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Chapter: 13- OPEN-CHANNEL FLOW -Problem: 50 >> A 3-ft-diameter semicircular channel made of unfinished concrete is to transport water to a distance of 1 mi uniformly. If the flow rate is to reach 90 ft3/s when the channel is full, determine the minimum elevation difference across the channel.
Answer Preview: To determine the minimum elevation difference across the semicircular channel you can use the princi…

, Chapter: 14- TURBOMACHINERY -Problem: 120 >> For each statement, choose whether the statement is true or false, and discuss your answer briefly:(a) A gear pump is a type of positive-displacement pump.(b) A rotary pump is a type of positive-displacement pump.(c) The pump performance curve (net head versus capacity) of a positive-displacement pump is nearly vertical throughout its recommended operating range at a given rotational speed.(d) At
Answer Preview: a True A gear pump is a type of positive displacement pump that uses meshed gears to trap and move fluid b True A rotary pump is a type of positive di…

, Chapter: 2- Properties Of Fluids -Problem: 54 >> Reconsider Prob. 2–53. Assuming a linear pressure increase during the compression, estimate the energy needed to compress the water isothermally. Data from Problem 53.A frictionless piston-cylinder device contains 10 kg of water at 20°C at atmospheric pressure. An external force F is then applied on the piston until the pressure inside the cylinder increases to 100 atm. Assuming the coefficient of
Answer Preview: To estimate the energy needed to compress the water isothermally assuming a linear pressure increase …

, Chapter: 8- INTERNAL FLOW -Problem: 112 >> What is the operating principle of variable-area flowmeters (rotameters)? How do they compare to other types of flowmeters with respect to cost, head loss, and reliability?
Answer Preview: Variable area flowmeters commonly known as rotameters operate on the principle of measuring fluid flow by varying the cross sectional area of a tapere…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 122 >> The primary dimensions of kinematic viscosity are(a) m·L/t2 (b) m/L·t (c) L2/t (d) L2/m·t (e) L/m·t2
Answer Preview: The primary dimensions of kinematic viscosity are e L mt 2 Explanation Kinematic viscosity is def…

, Chapter: 13- OPEN-CHANNEL FLOW -Problem: 150 >> Which choices are examples of open-channel flow?I. Flow of water in riversII. Draining of rainwater off highwaysIII. Upward draft of rain and snowIV. Sewer lines(a) I and II (b) I and III(c) II and III(d) I, II, and IV (e) I, II, III, and IV
Answer Preview: Open channel flow refers to the flow of fluids typically water in open channels such …

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, Chapter: 2- Properties Of Fluids -Problem: 44 >> The volume of an ideal gas is to be reduced by half by compressing it isothermally. Determine the required change in pressure.
Answer Preview: To determine the required change in pressure to reduce the volume of an id…

, Chapter: 8- INTERNAL FLOW -Problem: 166 >> Air flows in a 5 cm by 8 cm cross section rectangular duct at a velocity of 4 m/s at 1 atm and 15°C. The Reynolds number for this flow is(a) 13,605 (b) 16,745 (c) 17,690 (d) 21,770(e) 23,235
Answer Preview: The Reynolds number for the given airflow is c 17 690 To calculate the Reynolds number we can use …

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 52 >> A subtle point, often missed by students of fluid mechanics (and even their professors!), is that an inviscid region of flow is not the same as an irratational (potential) region of flow (Fig. P10–52C). Discuss the differences and similarities between these two approximations. Give an example of each. FIGURE P10–52C Transc
Answer Preview: In fluid mechanics both inviscid and irrotational flow are simplified approximations used to study fluid behavior under certain conditions While they …

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, Chapter: 15- INTRODUCTION TO COMPUTATIONAL FLUID DYNAMICS -Problem: 44 >> For each statement, choose whether the statement is true or false, and discuss your answer briefly:(a) The physical validity of a CFD solution always improves as the grid is refined.(b) The x-component of the Navier–Stokes equation is an example of a transport equation.(c) For the same number of nodes in a two-dimensional mesh, a structured grid typically has fewer cells than an unstructured trian
Answer Preview: a False The physical validity of a CFD solution does not always improve as the grid is refined In fact it is possible to refine the grid to the point where the solution becomes physically inaccurate T…

, Chapter: 2- Properties Of Fluids -Problem: 37 >> What does the coefficient of compressibility of a fluid represent? How does it differ from isothermal compressibility?
Answer Preview: The coefficient of compressibility often denoted as beta represents a fundamental property of a flui…

, Chapter: 8- INTERNAL FLOW -Problem: 10 >> What is the generally accepted value of the Reynolds number above which the flow in smooth pipes is turbulent?
Answer Preview: The generally accepted value of the Reynolds number above which the flow in smooth pipes is consider…

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, Chapter: 15- INTRODUCTION TO COMPUTATIONAL FLUID DYNAMICS -Problem: 8 >> Write a brief (a few sentences) discussion about the significance of each of the following in regards to an iterative CFD solution: (a) Initial conditions, (b) Residual, (c) Iteration,(d) Postprocessing.
Answer Preview: a Initial conditions Initial conditions are the values of the flow variables at the beginning of the simulation They are important because they determ…

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, Chapter: 8- INTERNAL FLOW -Problem: 126 >> The volume flow rate of liquid refrigerant-134a at 10°F (? = 83.31 lbm/ft3) is to be measured with a horizontal Venturi meter with a diameter of 5 in at the inlet and 2 in at the throat. If a differential pressure meter indicates a pressure drop of 6.4 psi, determine the flow rate of the refrigerant. Take the discharge coefficient of the Venturi meter to be 0.98.
Answer Preview: To determine the flow rate of refrigerant 134a using a Venturi meter you can use the following equat…

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, Chapter: 4- Fluid kinematics -Problem: 96 >> Reduce the following expression as far as possible: Transcribed Image Text: F(t) x=Bt d dt Jx=At e-2x² dx
Answer Preview: To reduce the expression F t d dt At Bt e 2x 2 dx as far as possible we ll first find the integral o…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 76 >> What is a trip wire, and what is its purpose?
Answer Preview: A tripwire is a simple mechanical or sensory device typically used for triggering a specific action or alarm when it is tripped or activated Its purpo…

, Chapter: 14- TURBOMACHINERY -Problem: 148 >> In wind turbines, the minimum wind speed at which useful power can be generated is called the(a) Rated speed (b) Cut-in speed(c) Cut-out speed(d) Available speed (e) Betz speed
Answer Preview: The minimum wind speed at which useful power can be generated in wind turbines is called the cut in …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 53 >> Albert Einstein is pondering how to write his (soon-to-be-famous) equation. He knows that energy E is a function of mass m and the speed of light c, but he doesn't know the functional relationship (E = m2c? E = mc4?). Pretend that Albert knows nothing about dimensional analysis, but since you are taking a fluid mechanics class, you help Albert come up with his equation. Use the step-by-step method
Answer Preview: Let s help Albert Einstein derive his famous equation using the method of dimensional analysis We ll …

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 7 >> What is the most important criterion for use of the modified pressure P´ rather than the thermodynamic pressure P in a solution of the Navier–Stokes equation?
Answer Preview: The most important criterion for using the modified pressure P often called the dynamic pressure rat…

, Chapter: 14- TURBOMACHINERY -Problem: 104 >> Verify that turbine specific speed and pump specific speed are related as follows: Transcribed Image Text: St Nsp Vn turbine =
Answer Preview: The equation you ve provided relates turbine specific speed Nst pump specific speed Nsp and specific …

, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 22 >> If a flow field is compressible, what can we say about the material derivative of density? What about if the flow field is incompressible?
Answer Preview: In a compressible flow field where changes in density ar…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 78 >> Although we usually think of a model as being smaller than the prototype, describe at least three situations in which it is better for the model to be larger than the prototype.
Answer Preview: While it s common to think of a model as being smaller than the prototype there are indeed situations where it is better for the model to be larger He…

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, Chapter: 15- INTRODUCTION TO COMPUTATIONAL FLUID DYNAMICS -Problem: 7 >> Suppose you are using CFD to simulate flow through a duct in which there is a circular cylinder as in Fig. P15–7C. The duct is long, but to save computer resources you choose a computational domain in the vicinity of the cylinder only. Explain why the downstream edge of the computational domain should be further from the cylinder than the upstream edge. FIGURE P15–7C
Answer Preview: The downstream edge of the computational domain should be further from the cylinder than the upstrea…

, Chapter: 8- INTERNAL FLOW -Problem: 128 >> The flow rate of water at 20°C (? = 998 kg/m3 and ? = 1.002 × 10–3 kg/m · s) through a 4-cm-diameter pipe is measured with a 2-cm-diameter nozzle meter equipped with an inverted air–water manometer. If the manometer indicates a differential water height of 44 cm, determine the volume flow rate of water and the head loss caused by the nozzle meter.
Answer Preview: To determine the volume flow rate of water and the head loss caused by the nozzle meter we can apply …

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 55 >> Consider fully developed Couette flow—flow between two infinite parallel plates separated by distance h, with the top plate moving and the bottom plate stationary as illustrated in Fig. P7–55. The flow is steady, incompressible, and two-dimensional in the xy-plane. Use the method of repeating variables to generate a dimensionless relationship for the x-component of fluid velocity u as a function o
Answer Preview: To generate a dimensionless relationship for the x component of fluid velocity u as a function of fluid viscosity top plate speed V distance h fluid d…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 17 >> Write a one-word description of each of the five terms in the incompressible Navier–Stokes equation,When the creeping flow approximation is made, only two of the five terms remain. Which two terms remain, and why is this significant? Transcribed Image Text: P ?V at I P(V.)V = P + pg + ?V²V II III V
Answer Preview: One word descriptions of the five terms in the incompressible Navier Stokes equation Local accele…

, Chapter: 15- INTRODUCTION TO COMPUTATIONAL FLUID DYNAMICS -Problem: 9 >> Briefly discuss how each of the following is used by CFD codes to speed up the iteration process: (a) Multigridding(b) Artificial time.
Answer Preview: a Multigridding is a technique that is used to speed up the iteration process in CFD codes by using …

, Chapter: 8- INTERNAL FLOW -Problem: 185 >> A pump moves water from a reservoir to another reservoir through a piping system at a rate of 0.15 m3/min. Both reservoirs are open to the atmosphere. The elevation difference between the two reservoirs is 35 m and the total head loss is estimated to be 4 m. If the efficiency of the motor pump unit is 65 percent, the electrical power input to the motor of the pump is(a) 1664 W (b) 1472 W (c) 1238
Answer Preview: To calculate the electrical power input to the motor of the pump you can use the following formu…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 79 >> Discuss the purpose of a moving ground belt in wind tunnel tests of flow over model automobiles. Think of an alternative if a moving ground belt is unavailable.
Answer Preview: A moving g…

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, Chapter: 8- INTERNAL FLOW -Problem: 122 >> Reconsider Prob. 8–121. Letting the pressure drop vary from 1 kPa to 10 kPa, evaluate the flow rate at intervals of 1 kPa, and plot it against the pressure drop. Data from Problem  8–121A Venturi meter equipped with a differential pressure gage is used to measure the flow rate of water at 15°C (? = 999.1 kg/m3) through a 5-cm-diameter horizontal pipe. The diameter of the Venturi neck is 3 cm, and
Answer Preview: To evaluate the flow rate at different pressure drops between 1 kPa and 10 kPa we can use the Ventur…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 23 >> A slipper-pad bearing (Fig. P10–23) is often encountered in lubrication problems. Oil flows between two blocks; the upper one is stationary, and the lower one is moving in this case. The drawing is not to scale; in actuality, h ? L. The thin gap between the blocks converges with increasing x. Specifically, gap height h decreases linearly from h0 at x = 0 to hL at x = L. Typically, the gap height l
Answer Preview: To generate a characteristic scale for pressure difference P P P0 in terms of L h0 viscosity and V v…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 113 >> When a capillary tube of small diameter D is inserted into a container of liquid, the liquid rises to height h inside the tube (Fig. P7–113). h is a function of liquid density ?, tube diameter D, gravitational constant g, contact angle ?, and the surface tension ?s of the liquid. (a) Generate a dimensionless relationship for h as a function of the given parameters.(b) Compare your result to the ex
Answer Preview: a To generate a dimensionless relationship for h as a function of the given parameters we can use th…

, Chapter: 8- INTERNAL FLOW -Problem: 170 >> Engine oil at 40°C (? = 876 kg/m3, ? = 0.2177 kg/m?s) flows in a 20-cm-diameter pipe at a velocity of 1.2 m/s. The pressure drop of oil for a pipe length of 20 m is(a) 4180 Pa (b) 5044 Pa (c) 6236 Pa (d) 7419 Pa(e) 8615 Pa
Answer Preview: To calculate the pressure drop of the engine oil flowing in the pipe you can use the Darcy Weisbach …

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 36 >> For each case, calculate an appropriate Reynolds number and indicate whether the flow can be approximated by the creeping flow equations. (a) A microorganism of diameter 5.0 ?m swims in room temperature water at a speed of 0.25 mm/s. (b) Engine oil at 140°C flows in the small gap of a lubricated automobile bearing. The gap is 0.0012 mm thick, and the characteristic velocity is 15 m/s. (c) A fog dr
Answer Preview: To determine whether the flow can be approximated by the creeping flow equations we need to calculate the Reynolds number Re for each case The Reynold…

, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 7 >> Transform the position x(vector) = (2, 4, –1) from Cartesian (x, y, z) coordinates to cylindrical (r, ?, z) coordinates, including units. The values of x(vector) are in units of meters.
Answer Preview: To transform the position vector x 2 4 1 from Cartesian coordinates to c…

, Chapter: 4- Fluid kinematics -Problem: 48 >> Explain the relationship between vorticity and rotationality.
Answer Preview: Vorticity and rotationality are two related concepts in fluid dynamics that describe the behavior of fluid motion particularly in the context of rotat…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 130 >> Which similarity condition is related to force-scale equivalence?(a) Geometric (b) Kinematic (c) Dynamic(d) Kinematic and dynamic (e) Geometric and kinematic
Answer Preview: The similarity condition related to force scale equivalence is c Dynamic The similarity condition re…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 135 >> Consider a boundary layer growing along a thin flat plate. This problem involves the following parameters: boundary layer thickness ?, downstream distance x, freestream velocity V, fluid density ?, and fluid viscosity ?. The number of expected nondimensional parameters ?s for this problem is(a) 5 (b) 4 (c) 3 (d) 2 (e) 1
Answer Preview: In fluid mechanics the Buckingham Pi theorem can be used to determine the number of dimensionless pa…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 45 >> Some students want to visualize flow over a spinning baseball. Their fluids laboratory has a nice water tunnel into which they can inject multicolored dye streaklines, so they decide to test a spinning baseball in the water tunnel (Fig. P7–45E). Similarity requires that they match both the Rey n olds number and the Strouhal number between their model test and the actual baseball that moves through
Answer Preview: To match the Reynolds number and Strouhal number between the model test and the actual baseball we c…

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, Chapter: 8- INTERNAL FLOW -Problem: 186 >> Consider a pipe that branches out into three parallel pipes and then rejoins at a junction downstream. All three pipes have the same diameters (D = 3 cm) and friction factors (f = 0.018). The lengths of pipe 1 and pipe 2 are 5 m and 8 m, respectively while the velocities of the fluid in pipe 2 and pipe 3 are 2 m/s and 4 m/s, respectively. The length of pipe 3 is(a) 8 m (b) 5 m (c) 4 m (d) 2 m (e)
Answer Preview: To solve this problem we can use the principles of fluid mechanics and the continuity equation The c…

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, Chapter: 14- TURBOMACHINERY -Problem: 150 >> The available power from a wind turbine is calculated to be 50 kW when the wind speed is 5 m/s. If the wind velocity is doubled, the available wind power becomes(a) 50 kW (b) 100 kW (c) 200 kW (d) 400 kW(e) 800 kW
Answer Preview: The available power from a wind turbine is pro…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 137 >> Consider a boundary layer growing along a thin flat plate. This problem involves the following parameters: boundary layer thickness ?, downstream distance x, free-stream velocity V, fluid density ?, and fluid viscosity ?. The number of primary dimensions represented in this problem is(a) 1 (b) 2 (c) 3 (d) 4 (e) 5
Answer Preview: In fluid mechanics the Buckingham Pi theorem also known as the Buckingham Pi m…

, Chapter: 2- Properties Of Fluids -Problem: 149 >> The surface tension of soap water at 20°C is ?s = 0.025 N/m. The gage pressure inside a soap bubble of diameter 2 cm at 20°C is(a) 10 Pa (b) 5 Pa (c) 20 Pa (d) 40 Pa (e) 0.5 Pa
Answer Preview: To find the gauge pressure inside a soap bubble you can …

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 37 >> Estimate the speed and Reynolds number of the sperm shown in Fig. 10–10. Is this microorganism swimming under creeping flow conditions? Assume it is swimming in room-temperature water. Figure 10-10 Transcribed Image Text: 2
Answer Preview: Given data The temperature of the water T s 20 0 C The diame…

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, Chapter: 8- INTERNAL FLOW -Problem: 175 >> Consider air flow in a 10-cm-diameter pipe at a high velocity so that the Reynolds number is very large. The roughness of the pipe is 0.002 mm. The friction factor for this flow is(a) 0.0311 (b) 0.0290 (c) 0.0247 (d) 0.0206 (e) 0.0163
Answer Preview: To calculate the friction factor f for high velocity flow in a pipe with a given roughness you can u…

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, Chapter: 4- Fluid kinematics -Problem: 68 >> From the results of Prob. 4–67,(a) Is this flow rotational or irrotational?(b) Calculate the z-component of vorticity for this flow field. Data from Problem 67Consider the steady, incompressible, two-dimensional flow field of Prob. 4–64. Using the results of Prob. 4–64(a), do the following:From the fundamental definition of the rate of rotation (average rotation rate of two initially perpendicular
Answer Preview: a A flow field is rotational if the vorticity vector is non zero The vorticity vector is defined as …

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, Chapter: 14- TURBOMACHINERY -Problem: 147 >> In a hydroelectric power plant, water flows through a large tube through the dam. This tube is called a(a) Tailrace(b) Draft tube (c) Runner (d) Penstock(e) Propeller
Answer Preview: The large tube through which water flows through a dam in a hydroelectric power plant is …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 82 >> What is the rule of thumb about the Mach number limit in order that the incompressible flow approximation is reasonable? Explain why wind tunnel results would be incorrect if this rule of thumb were violated.
Answer Preview: The rule of thumb regarding the Mach number limit for the incompressible flow approximation is that it is reasonable to use this approximation when th…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 78 >> Compare flow separation for a laminar versus turbulent boundary layer. Specifically, which case is more resistant to flow separation? Why? Based on your answer, explain why golf balls have dimples.
Answer Preview: Flow separation is a phenomenon that can occur in both laminar and turbulent boundary layers but the characteristics and resistance to separation diff…

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, Chapter: 2- Properties Of Fluids -Problem: 147 >> A viscometer constructed of two 30-cm-long concentric cylinders is used to measure the viscosity of a fluid. The outer diameter of the inner cylinder is 9 cm, and the gap between the two cylinders is 0.18 cm. The inner cylinder is rotated at 250 rpm, and the torque is measured to be 1.4 N·m. The viscosity of the fluid is(a) 0.0084 N·s/m2 (b) 0.017 N·s/m2 (c) 0.062 N·s/m2(d) 0.0049 N·s/m2 (e) 0.56
Answer Preview: To find the viscosity of the fluid you can use the formula for the shear stress in a viscometer wit…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 73 >> For each statement, choose whether the statement is true or false and discuss your answer briefly. These statements concern a laminar boundary layer on a flat plate (Fig. P10–73C).(a) At a given x-location, if the Reynolds number were to increase, the boundary layer thickness would also increase.(b) As outer flow velocity increases, so does the boundary layer thickness.(c) As the fluid viscosity i
Answer Preview: a False If the Reynolds number were to increase the boundary layer thickness would decrease This is because the Reynolds number is a measure of the ra…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 8 >> A vacuum gage connected to a chamber reads 36 kPa at a location where the atmospheric pressure is 92 kPa. Determine the absolute pressure in the chamber.
Answer Preview: To determine the absolute pressure in the chamber y…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 69 >> Bill is working on an electrical circuit problem. He remembers from his electrical engineering class that voltage drop ?E is a function of electrical current I and electrical resistance R. Unfortunately, he does not recall the exact form of the equation for ?E. However, he is taking a fluid mechanics class and decides to use his newly acquired knowledge about dimensional analysis to recall the for
Answer Preview: Dimensional Analysis of Voltage Drop Repeating Variables Method Identify the variables …

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 72 >> We usually think of boundary layers as occurring along solid walls. However, there are other flow situations in which the boundary layer approximation is also appropriate. Name three such flows, and explain why the boundary layer approximation is appropriate.
Answer Preview: The boundary layer approximation is a fundamental concept in fluid dynamics that is not limited to flow along solid walls It can be applied to various …

, Chapter: 15- INTRODUCTION TO COMPUTATIONAL FLUID DYNAMICS -Problem: 15 >> List six boundary conditions that are used with CFD to solve incompressible fluid flow problems. For each one, provide a brief description and give an example of how that boundary condition is used.
Answer Preview: Six boundary conditions that are used with CFD to solve incompressible fluid flow problems are Velocity inlet This boundary condition specifies the velocity of the fluid entering the computational dom…

, Chapter: 8- INTERNAL FLOW -Problem: 174 >> Air at 1 atm and 258C (v = 1.562 × 10–5 m2/s) flows in a 9-cm-diameter cast iron pipe at a velocity of 5 m/s. The roughness of the pipe is 0.26 mm. The head loss for a pipe length of 24 m is(a) 8.1 m (b) 10.2 m (c) 12.9 m (d) 15.5 m (e) 23.7 m
Answer Preview: To calculate the head loss in a pipe you can use the Darcy Weisbach equation which relates the head …

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, Chapter: 14- TURBOMACHINERY -Problem: 139 >> A centrifugal blower rotates at 1400 rpm. Air enters the impeller normal to the blades (?1 = 0°) and exits at an angle of 25° (?2 = 25°). The inlet radius is r1 = 6.5 cm, and the inlet blade width b1 = 8.5 cm. The outlet radius and blade width are r2 = 12 cm and b2 = 4.5 cm, respectively. The volume flow rate is 0.22 m3/s. What is the net head produced by this blower in meters of air?(a) 12.3 m (b
Answer Preview: To calculate the net head produced by the centrifugal blower we can use the following equation Net h…

, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 31 >> Consider the following steady, three-dimensional velocity field in Cartesian coordinates:where a, b, c, and d are constants. Under what conditions is this flow field incompressible? Transcribed Image Text: V= (u, v, w) = (ax²y + b)i + cxy²7+ dx²yk
Answer Preview: For a flow field to be incompressible the divergence of the velocity field must be equal to zero In …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 123 >> The thermal conductivity of a substance may be defined as the rate of heat transfer per unit length per unit temperature difference. The primary dimensions of thermal conductivity are(a) m2·L/t2·T (b) m2·L2/t·T (c) L2/m·t2·T(d) m·L/t3·T (e) m·L2/t3·T
Answer Preview: The thermal conductivity of a substance is defined as the rate of heat t…

, Chapter: 14- TURBOMACHINERY -Problem: 77 >> Briefly discuss the main difference in the way that dynamic pumps and reaction turbines are classified as centrifugal (radial), mixed flow, or axial.
Answer Preview: The main difference in how dynamic pumps and reaction turbines are classified as centrifugal radial mixed flow or axial lies in their operational prin…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 53 >> What flow property determines whether a region of flow is rotational or irrotational? Discuss.
Answer Preview: The flow property that determines whether a region of flow is rotational or irrotational is known as …

, Chapter: 14- TURBOMACHINERY -Problem: 74 >> Name and briefly describe the differences between the two basic types of dynamic turbine.
Answer Preview: The two basic types of dynamic turbines are axial flow turbines and radial flow turbines Axial Flow …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 71 >> A liquid of density ? and viscosity ? is pumped at volume flow rate V? through a pump of diameter D. The blades of the pump rotate at angular velocity v. The pump supplies a pressure rise DP to the liquid. Using dimensional analysis, generate a dimensionless relationship for ?P as a function of the other parameters in the problem. Identify any established non dimensional parameters that appear in
Answer Preview: To generate a dimensionless relationship for P pressure rise as a function of the other parameters in the problem density viscosity volume flow rate V …

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 121 >> Which one is not a primary dimension?(a) Velocity (b) Time (c) Electric current(d) Temperature (e) Mass
Answer Preview: The primary dimensions as defined in the International System of Units SI inclu…

, Chapter: 14- TURBOMACHINERY -Problem: 73 >> What is a draft tube, and what is its purpose? Describe what would happen if turbomachinery designers did not pay attention to the design of the draft tube.
Answer Preview: A draft tube is a key component often found in the design of hydraulic turbines specifically in reaction turbines like Francis and Kaplan turbines Its …

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, Chapter: 2- Properties Of Fluids -Problem: 146 >> The dynamic viscosity of air at 20°C and 200 kPa is 1.83 × 10–5 kg/m·s. The kinematic viscosity of air at this state is(a) 0.525 × 10–5 m2/s (b) 0.77 × 10–5 m2/s(c) 1.47 × 10–5 m2/s (d) 1.83 × 10–5 m2/s(e) 0.380 × 10–5 m2/s
Answer Preview: The kinematic viscosity of a fluid is defined as the dynamic viscosity divided by the density of the …

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, Chapter: 14- TURBOMACHINERY -Problem: 78 >> A hydroelectric plant has 14 identical Francis turbines, a gross head of 284 m, and a volume flow rate of 13.6 m3/s through each turbine. The water is at 25°C. The efficiencies are ?turbine = 95.9%, ?generator 5 94.2%, and ?other 5 95.6%, where ?other accounts for all other mechanical energy losses. Estimate the electrical power production from this plant in MW.
Answer Preview: To estimate the electrical power production from the hydroelectric plant we can break down the proce…

, Chapter: 8- INTERNAL FLOW -Problem: 111 >> Explain how flow rate is measured with a turbine flowmeter, and discuss how they compare to other types of flowmeters with respect to cost, head loss, and accuracy.
Answer Preview: A turbine flowmeter is a type of flowmeter used to measure the flow rate of fluids such as liquids and gases in a pipeline or conduit It operates on t…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 60 >> Consider a steady, two-dimensional, incompressible, irrotational velocity field specified by its velocity potential function,(a) Calculate velocity components u and v. (b) Verify that the velocity field is irrotational in the region in which ? applies. (c) Generate an expression for the stream function in this region. Tran
Answer Preview: To solve this problem we ll first calculate the velocity components u and v using the given velocity …

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, Chapter: 8- INTERNAL FLOW -Problem: 121 >> A Venturi meter equipped with a differential pressure gage is used to measure the flow rate of water at 15°C (? = 999.1 kg/m3) through a 5-cm-diameter horizontal pipe. The diameter of the Venturi neck is 3 cm, and the measured pressure drop is 5 kPa. Taking the discharge coefficient to be 0.98, determine the volume flow rate of water and the average velocity through the pipe.
Answer Preview: To determine the volume flow rate of water and the average velocity through the pipe using a Venturi meter you can use the Bernoulli s equation and th…

, Chapter: 4- Fluid kinematics -Problem: 72 >> Consider a steady, two-dimensional, incompressible flow field in the xy-plane. The linear strain rate in the x-direction is 2.5 s–1. Calculate the linear strain rate in the y-direction.
Answer Preview: In a steady two dimensional incompressible flow field the li…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 133 >> A centrifugal pump consists simply of a shaft and a few blades attached normally to the shaft. If the shaft is rotated at a constant rate of 2400 rpm, what would the theoretical pump head due to this rotation be? Take the impeller diameter to be 35 cm and neglect the blade tip effects.
Answer Preview: The theoretical pump head due to the rotation of a centrifugal pump can be calculated using …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 51 >> A stirrer is used to mix chemicals in a large tank (Fig. P7–51). The shaft power W? supplied to the stirrer blades is a function of stirrer diameter D, liquid density r, liquid viscosity ?, and the angular velocity ? of the spinning blades. Use the method of repeating variables to generate a dimensionless relationship between these parameters. Show all your work and be sure to identify your ? grou
Answer Preview: Method of Repeating Variables The method of repeating variables is a systematic way to generate dimensionless relationships between physical quantitie…

, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 71 >> We briefly mention the compressible stream function ?? in this chapter, defined in Cartesian coordinates as ?u = (???/?y) and ?v = –(???/?x). What are the primary dimensions of ??? Write the units of ?? in primary SI units and in primary English units.
Answer Preview: The compressible stream function is a dimensionless quantity and it doesn t have prim…

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 115 >> A water tank is being towed on an uphill road that makes 14° with the horizontal with a constant acceleration of 3.5 m/s2 in the direction of motion. Determine the angle the free surface of water makes with the horizontal. What would your answer be if the direction of motion were downward on the same road with the same acceleration?
Answer Preview: Let s start by calculating the angle the free surface of water makes with the horizontal when the water tank is being towed uphill with a constant acc…

, Chapter: 8- INTERNAL FLOW -Problem: 168 >> Consider laminar flow of water in a 0.8-cm-diameter pipe at a rate of 1.15 L/min. The velocity of water halfway between the surface and the center of the pipe is(a) 0.381 m/s (b) 0.762 m/s (c) 1.15 m/s(d) 0.874 m/s (e) 0.572 m/s
Answer Preview: The velocity of water halfway between the surface and the center of the pip…

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, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 17 >> Consider a spiraling line vortex/sink flow in the xy-or r?-plane as sketched in Fig. P9–17. The two-dimensional cylindrical velocity components (ur, u?) for this flow field are ur = C/2?r and u? = ?/2pr, where C and G are constants (m is negative and ? is positive). Transform these two-dimensional cylindrical velocity components into two dimensional Cartesian velocity components (u, v). Your final
Answer Preview: To transform two dimensional cylindrical velocity components ur u into two dimensional Cartesian vel…

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, Chapter: 8- INTERNAL FLOW -Problem: 138 >> Oil at 20°C is flowing steadily through a 5-cmdiameter 40-m-long pipe. The pressures at the pipe inlet and outlet are measured to be 745 and 97.0 kPa, respectively, and the flow is expected to be laminar. Determine the flow rate of oil through the pipe, assuming fully developed flow and that the pipe is (a) Horizontal, (b) Inclined 15° upward, (c) Inclined 15° downward. Also, verify that the flow
Answer Preview: To determine the flow rate of oil through the pipe and verify that the flow is laminar you can use the Hagen Poiseuille equation for laminar flow in a …

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 44 >> Consider the common situation in which a researcher is trying to match the Reynolds number of a large prototype vehicle with that of a small-scale model in a wind tunnel. Is it better for the air in the wind tunnel to be cold or hot? Why? Support your argument by comparing wind tunnel air at 10°C and at 40°C, all else being equal.
Answer Preview: In the context of matching the Reynolds number of a large prototype vehicle with that of a small scale model in a wind tunnel it is generally better f…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 145 >> A vertical, frictionless piston–cylinder device contains a gas at 500 kPa. The atmospheric pressure outside is 100 kPa, and the piston area is 30 cm2. Determine the mass of the piston.
Answer Preview: To determine the mass of the piston in a vertical frictionless piston cylinder device you can use th…

, Chapter: 8- INTERNAL FLOW -Problem: 125 >> A vertical Venturi meter equipped with a differential pressure gage shown in Fig. P8–125 is used to measure the flow rate of liquid propane at 10°C (? = 514.7 kg/m3) through an 10-cm-diameter vertical pipe. For a discharge coefficient of 0.98, determine the volume flow rate of propane through the pipe. Figure 125 Transcrib
Answer Preview: To determine the volume flow rate of liquid propane through the pipe using a vertical Venturi meter …

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, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 134 >> A steady, two-dimensional, incompressible flow field in the xy-plane has a stream function given by ? = ax2 + by2 + cy, where a, b, and c are constants. The expression for the velocity component v is(a) 2ax (b) 2by + c (c) –2ax (d) –2by – c(e) 2ax + 2by + c
Answer Preview: In a two dimensional incompressible flow field in the xy plane the velocity comp…

, Chapter: 8- INTERNAL FLOW -Problem: 127 >> A 22-L kerosene tank (? = 820 kg/m3) is filled with a 2-cm-diameter hose equipped with a 1.5-cm-diameter nozzle meter. If it takes 20 s to fill the tank, determine the pressure difference indicated by the nozzle meter.
Answer Preview: To determine the pressure difference indicated by the nozzle meter you can use Bernoulli s equation …

, Chapter: 2- Properties Of Fluids -Problem: 140 >> The coefficient of compressibility of a truly incompressible substance is(a) 0 (b) 0.5 (c) 1 (d) 100 (e) Infinity
Answer Preview: The coefficient of compressibility also known as the bulk modul…

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, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 20 >> The product rule can be applied to the divergence of scalar f times vectorExpand both sides of this equation in Cartesian coordinates and verify that it is correct. Transcribed Image Text: Gas: V.(fG) = GVƒ+ ƒV. G.
Answer Preview: To verify the correctness of the given equation using the product rule we can expand both sides of t…

, Chapter: 9- DIFFERENTIAL ANALYSIS OF FLUID FLOW -Problem: 129 >> The Navier-Stokes equation is also known as(a) Newton’s first law (b) Newton’s second law(c) Newton’s third law (d) Continuity equation(e) Energy equation
Answer Preview: b Newtons second law The Navier Stokes equation is indeed known as Newton s second law of motion fo…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 38 >> What is the main difference between the steady, incompressible Bernoulli equation for irrotational regions of flow, and the steady incompressible Bernoulli equation for rotational but inviscid regions of flow?
Answer Preview: The main difference between the steady incompressible Bernoulli equation for irrotational regions of …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 117 >> Engineers at MIT have developed a mechanical of a tuna fish to study its locomotion. The “Robotuna” shown in Fig. P7–117 is 1.0 m long and swims at speeds up to 2.0 m/s. Real bluefin tuna can exceed 3.0 m in length and have been clocked at speeds greater than 13 m/s. How fast would the 1.0-m Robotuna need to swim in order to match the Reynolds number of a real tuna that is 2.0 m long and swims at
Answer Preview: To match the Reynolds number of a real tuna we need to find the velocity at which the 1 0 meter R…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 61 >> Consider a planar irrotational region of flow in the r?-plane. Show that stream function ? satisfies the Laplace equation in cylindrical coordinates.
Answer Preview: To show that the stream function satisfies the Laplace equation in cylindrical coordinates for a pla…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 114 >> Repeat part (a) of Prob. 7–113, except instead of height h, find a functional relationship for the time scale trise needed for the liquid to climb up to its final height in the capillary tube. Data from Problem 7–113When a capillary tube of small diameter D is inserted into a container of liquid, the liquid rises to height h inside the tube (Fig. P7–113). h is a function of liquid density ?, tube
Answer Preview: a To generate a dimensionless relationship for h as a function of the given parameters we can use th…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 88 >> Consider two pressure taps along the wall of a laminar boundary layer as in Fig. P10–87. The fluid is air at 25°C, U1 = 10.3 m/s, and the static pressure P1 is 2.44 Pa greater than static pressure P2, as measured by a very sensitive differential pressure transducer. Is outer flow velocity U2 greater than, equal to, or less than outer flow velocity U1? Explain. Estimate U2. FIGURE P10–87
Answer Preview: The outer flow velocity U2 is less than the outer flow velocity U1 To understand this we can conside…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 35 >> Estimate the speed at which you would need to swim in room temperature water to be in the creeping flow regime. (An order-of-magnitude estimate will suffice.) Discuss.
Answer Preview: To estimate the speed at which you would need to swim in room temperature water to be in the creepin…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 77 >> Discuss the implication of an inflection point in a boundary layer profile. Specifically, does the existence of an inflection point infer a favorable or adverse pressure gradient? Explain.
Answer Preview: An inflection point in a boundary layer profile is a point where the second derivative of the velocity profile with respect to the wall normal distanc…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 81 >> Define wind tunnel blockage. What is the rule of thumb about the maximum acceptable blockage for a wind tunnel test? Explain why there would be measurement errors if the blockage were significantly higher than this value.
Answer Preview: Wind tunnel blockage refers to the obstruction or interference caused by the presence of a model or test object inside a wind tunnel When conducting w…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 85 >> Air flows parallel to a speed limit sign along the highway at speed V = 8.5 m/s. The temperature of the air is 25°C, and the width W of the sign parallel to the flow direction (i.e., its length) is 0.45 m. Is the boundary layer on the sign laminar or turbulent or transitional?
Answer Preview: To determine whether the boundary layer on the sign is laminar turbulent or transitional you can use …

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 185 >> A 1.8-m-diameter and 3.6-m-long cylindrical container contains a fluid with a specific gravity of 0.73. The container is positioned vertically and is full of the fluid. Disregarding atmospheric pressure, the hydrostatic force acting on the top and bottom surfaces of this container, respectively, are(a) 0 kN, 65.6 kN (b) 65.6 kN, 0 kN (c) 65.6 kN, 65.6 kN(d) 25.5 kN, 0 kN (e) 0 kN, 25.5 kN
Answer Preview: To find the hydrostatic forces acting on the top and bottom surfaces of the cylindrical container yo…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 44 >> Water at T = 20°C rotates as a rigid body about the z-axis in a spinning cylindrical container (Fig. P10–44). There are no viscous stresses since the water moves as a solid body; thus the Euler equation is appropriate. (We neglect viscous stresses caused by air acting on the water surface.) Integrate the Euler equation to generate an expression for pressure as a function of r and z everywhere in t
Answer Preview: The Euler equation for a rotating fluid in a cylindrical container is given by P v g where P is the …

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 149 >> When measuring small pressure differences with a manometer, often one arm of the manometer is inclined to improve the accuracy of the reading. (The pressure difference is still proportional to the vertical distance and not the actual length of the fluid along the tube.) The air pressure in a circular duct is to be measured using a manometer whose open arm is inclined 25° from the horizontal, as sh
Answer Preview: To determine the gauge pressure of the air in the duct and the length of the fluid column in the inclined arm above the fluid level in the vertical ar…

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, Chapter: 2- Properties Of Fluids -Problem: 150 >> A 0.4-mm-diameter glass tube is inserted into water at 20°C in a cup. The surface tension of water at 20°C is ?s = 0.073 N/m. The contact angle can be taken as zero degrees. The capillary rise of water in the tube is(a) 2.9 cm (b) 7.4 cm (c) 5.1 cm(d) 9.3 cm (e) 14.0 cm
Answer Preview: The capillary rise of a liquid in a thin tube can be calculated using the Jurin s Law formula h 2s c…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 113 >> A water tank is being towed by a truck on a level road, and the angle the free surface makes with the horizontal is measured to be 12°. Determine the acceleration of the truck.
Answer Preview: To determine the acceleration of the truck towing the water tank we can use the following physics pr…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 50 >> Repeat Prob. 7–49, but with an additional independent parameter included, namely, the speed of sound c in the fluid. Use the method of repeating variables to generate a dimensionless relationship for Kármán vortex shedding frequency fk as a function of free-stream speed V, fluid density ?, fluid viscosity ?, cylinder diameter D, and speed of sound c. Show all your work. Data from Problem 49A perio
Answer Preview: To solve this problem we will use the Buckingham Pi theorem This theorem states that the number of i…

, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 131 >> A one-third scale model of a car is to be tested in a wind tunnel. The conditions of the actual car are V = 75 km/h and T = 0°C and the air temperature in the wind tunnel is 20°C. The properties of air at 1 atm and 0°C: ? = 1.292 kg/m3, ? = 1.338 × 10–5 m2/s.The properties of air at 1 atm and 20°C: ? = 1.204 kg/m3, ? = 1.516 × 10–5 m2/s. In order to achieve similarity between the model and the pro
Answer Preview: In order to achieve similarity between the model and the prototype the following conditions must be …

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 87 >> Repeat Prob. 3–86 for 0.4-m-wide concrete blocks. Data from Problem 86A retaining wall against a mud slide is to be constructed by placing 1.2-m-high and 0.25-m-wide rectangular concrete blocks (? = 2700 kg/m3) side by side, as shown in Fig. P3–86. The friction coefficient between the ground and the concrete blocks is f = 0.4, and the density of the mud is about 1400 kg/m3. There is concern that t
Answer Preview: In Problem 3 86 we calculated the mud height at which the concrete blocks would start sliding and tip over for blocks that were 0 25 meters wide Now w…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 58 >> Two water tanks are connected to each other through a mercury manometer with inclined tubes, as shown in Fig. P3–58. If the pressure difference between the two tanks is 20 kPa, calculate a and ?. FIGURE P3–58 Transcribed Image Text: Water A a 26.8 cm 2a a Mercury SG = 13.6 Water B
Answer Preview: To calculate a and we can use the following steps Calculate the height difference between the two wa…

, Chapter: 13- OPEN-CHANNEL FLOW -Problem: 68 >> How does gradually varied flow (GVF) differ from rapidly varied flow (RVF)?
Answer Preview: Gradually Varied Flow GVF and Rapidly Varied Flow RVF are two different types of flow conditions that occur in open channels or rivers and they differ …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 57 >> The speed of sound c in an ideal gas is known to be a function of the ratio of specific heats k, absolute temperature T, and specific ideal gas constant Rgas (Fig. P7–57). Showing all your work, use dimensional analysis to find the functional relationship between these parameters. Fig. P7–57 Transcribed Image Text:
Answer Preview: To use dimensional analysis to find the functional relationship between the speed of sound c ratio o…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 111 >> Consider two identical glasses of water, one stationary and the other moving on a horizontal plane with constant acceleration. Assuming no splashing or spilling occurs, which glass will have a higher pressure at the (a) Front, (b) Midpoint, (c) Back of the bottom surface?
Answer Preview: In this scenario we can analyze the situation by considering the principles of fluid dynamics and the effects of acceleration on a fluid in this case …

, Chapter: 13- OPEN-CHANNEL FLOW -Problem: 92 >> While the GVF equation cannot be used to predict a hydraulic jump directly, it can be coupled with the ideal hydraulic jump depth ratio equation in order to help locate the position at which a jump will occur in a channel. Consider a jump created in a wide (Rh ? y) horizontal (S0 = 0) laboratory flume having a length of 3m and a Manning coefficient of 0.009. The supercritical flow under the head g
Answer Preview: To determine the location of the hydraulic jump in the given flume we will follow these steps a Calculate the critical depth and verify the initial an…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 112 >> Consider a vertical cylindrical container partially filled with water. Now the cylinder is rotated about its axis at a specified angular velocity, and rigid-body motion is established. Discuss how the pressure will be affected at the midpoint and at the edges of the bottom surface due to rotation.
Answer Preview: When a vertical cylindrical container partially filled with water is rotated about its axis it under…

, Chapter: 13- OPEN-CHANNEL FLOW -Problem: 133 >> Consider two identical channels, one rectangular of bottom width b and one circular of diameter D, with identical flow rates, bottom slopes, and surface linings. If the flow height in the rectangular channel is also b and the circular channel is flowing half-full, determine the relation between b and D.
Answer Preview: To determine the relation between the bottom width b of the rectangular channel and the diameter D of the circular channel given that they have identi…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 124 >> The primary dimensions of the gas constant over the universal gas constant R/Ru are(a) L2/t2·T (b) m·L/N (c) m/t·N·T(d) m/L3 (e) N/m
Answer Preview: The gas constant R and the universal gas constant Ru have different units The universal …

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 184 >> A 2-m-long and 3-m-wide horizontal rectangular plate is submerged in water. The distance of the top surface from the free surface is 5 m. The atmospheric pressure is 95 kPa. Considering atmospheric pressure, the hydrostatic force acting on the top surface of this plate is(a) 307 kN (b) 688 kN (c) 747 kN(d) 864 kN (e) 2950 kN
Answer Preview: To find the hydrostatic force acting on the top surface of the rectangular plate submerged in water …

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 142 >> The pressure in a steam boiler is given to be 90 kgf/cm2. Express this pressure in psi, kPa, atm, and bars.
Answer Preview: To express the pressure of 90 kgf cm in different units you can use the following …

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 21 >> A good swimmer can swim 100 m in about a minute. If a swimmer’s body is 1.85 m long, how many body lengths does he swim per second? Repeat the calculation for the sperm of Fig. 10–10. In other words, how many body lengths does the sperm swim per second? Use the sperm’s whole body length, not just that of his head, for the calculation. Compare the two results and discuss. Figure 10-10
Answer Preview: To calculate how many body lengths a swimmer and a sperm swim per second we can use the formula Numb…

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 115 >> Sound intensity I is defined as the acoustic power per unit area emanating from a sound source. We know that I is a function of sound pressure level P (dimensions of pressure) and fluid properties ? (density) and speed of sound c.(a) Use the method of repeating variables in mass-based primary dimensions to generate a dimensionless relationship for I as a function of the other parameters. Show all
Answer Preview: a To generate a dimensionless relationship for sound intensity I as a function of sound pressure lev…

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, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 79 >> In your own words, summarize the five steps of the boundary layer procedure.
Answer Preview: The five steps of the boundary layer procedure are Calculate the outer flow velocity distribution U …

, Chapter: 4- Fluid kinematics -Problem: 1 >> What does the word kinematics mean? Explain what the study of fluid kinematics involves.
Answer Preview: Kinematics is a branch of physics that deals with the description of motion without considering the underlying causes of that motion forces In simpler …

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, Chapter: 7- DIMENSIONAL ANALYSIS AND MODELING -Problem: 52 >> Repeat Prob. 7–51 except do not assume that the tank is large. Instead, let tank diameter Dtank and average liquid depth htank be additional relevant parameters. Data from Exercises 51A stirrer is used to mix chemicals in a large tank (Fig. P7–51). The shaft power W? supplied to the stirrer blades is a function of stirrer diameter D, liquid density r, liquid viscosity ?, and the angular velocity ?
Answer Preview: To generate a dimensionless relationship between the parameters using the method of repeating variables we first need to identify the repeating variab…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 71 >> Superpose a uniform stream of velocity V? and a line source of strength V?/L at the origin. This generates potential flow over a two-dimensional half-body called the Rankine half-body (Fig. P10–71). One unique streamline is the dividing streamline that forms a dividing line between free-stream fluid coming from the left and fluid coming from the source.(a) Generate an equation for the dividing str
Answer Preview: a The stream function for a uniform stream of velocity V in the x direction is given by V y The stream function for a line source of strength V L at t…

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 167 >> A 5-m-long, 4-m-high tank contains 2.5-m-deep water when not in motion and is open to the atmosphere through a vent in the middle. The tank is now accelerated to the right on a level surface at 2 m/s2. Determine the maximum pressure in the tank relative to the atmospheric pressure. Transcribed Image Text:
Answer Preview: To determine the maximum pressure in the tank relative to atmospheric pressure we need to consider the effects of acceleration on the water inside the …

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 41 >> The maximum blood pressure in the upper arm of a healthy person is about 120 mmHg. If a vertical tube open to the atmosphere is connected to the vein in the arm of the person, determine how high the blood will rise in the tube. Take the density of the blood to be 1040 kg/m3. Transcribed Image Text:
Answer Preview: To determine how high the blood will rise in the vertical tube when connected to the vein we can use …

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 189 >> A 3-kg object with a density of 7500 kg/m3 is placed in water. The weight of this object in water is(a) 29.4 N (b) 25.5 N (c) 14.7 N (d) 30 N (e) 3 N
Answer Preview: To find the weight of the 3 kg object in water you can use the concept of buoyancy and Archimedes pr…

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, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 37 >> A manometer containing oil (? =  850 kg/m3) is attached to a tank filled with air. If the oil-level difference between the two columns is 150 cm and the atmospheric pressure is 98 kPa, determine the absolute pressure of the air in the tank.
Answer Preview: To determine the absolute pressure of the air in the tank you can use the hydrostatic pressure formu…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 54 >> Write the Bernoulli equation, and discuss how it differs between an inviscid, rotational region of flow and a viscous, irrotational region of flow. Which case is more restrictive (in regards to the Bernoulli equation)?
Answer Preview: The Bernoulli equation is a fundamental equation in fluid mechanics that relates the pressure veloci…

, Chapter: 3- PRESSURE AND FLUID STATICS -Problem: 43 >> Consider a U-tube whose arms are open to the atmosphere. Now water is poured into the U-tube from one arm, and light oil (? = 790 kg/m3) from the other. One arm contains 70-cm-high water, while the other arm contains both fluids with an oil-to-water height ratio of 6. Determine the height of each fluid in that arm. Transcr
Answer Preview: To determine the height of each fluid in the U tube we can use th…

, Chapter: 10- APPROXIMATE SOLUTIONS OF THE NAVIER–STOKES EQUATION -Problem: 59 >> Consider a steady, two-dimensional, incompressible, irrotational velocity field specified by its velocity potential function,(a) Calculate

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