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Chapter: 5 -Problem: 19 >> If the velocity in the channel of Problem 5.18 is given as u = 8[exp(y) – 1] m/s and the channel width is 2 m, what is the discharge in the channel and what is the mean velocity? Data from Problem 5.18The rectangular channel shown is 1.2 m wide. What is the discharge in the channel? Transcribed Image Text:
Answer Preview: The first step is to use the given velocity profile to find the discharge in the channel We can …

, Chapter: 4 -Problem: 8 >> There is a gasoline spill in a major river. The mayor of a large downstream city demands an estimate of how many hours it will take for the spill to get to the water supply plant intake. The emergency responders measure the speed of the leading edge of the spill, effectively focusing on one particle of fluid. Meanwhile, environmental engineers at the local university employ a computer model, which
Answer Preview: b The responders have a Lagrangian approach and the engine…

, Chapter: 10 -Problem: 72 >> Water is flowing through a gate valve (Kv = 0.2). Calculate the value of b in units of mm. The pipe is horizontal. The flow is steady and fully developed. Over a 3-meter pipe length upstream of the valve, the EGL drops by a = 430 mm. The pipe ID is 0.25 m and the friction factor in the pipe is 0.03. Choose the closest answer (mm): (a) 180, (b) 240, (c) 320, (d) 340, (e) 360.
Answer Preview: To calculate the value of b in units of mm we need to use the equation for head loss due to a valve …

, Chapter: 5 -Problem: 71 >> The globe valve shown in the figure is a very common device to control flow rate. The flow comes through the pipe at the left and then passes through a minimum area formed by the disc and valve seat. As the valve is closed, the area for flow between the disc and valve is reduced. The flow area can be approximated by the annular region between the disc and the seat. The pressure drop across the val
Answer Preview: To calculate the pressure drop across the valve we can use the following equation P 2 g h v 2 2 g wh…

, Chapter: 13 -Problem: 54 >> What is the water discharge over a rectangular weir 4 ft high and 18 ft long in a rectangular channel 18 ft wide if the head on the weir is 2.2 ft?
Answer Preview: The water discharge over a rectangular weir can be calculated using the f…

, Chapter: 9 -Problem: 9 >> A plate 2 mm thick and 3 m wide (normal to the page) is pulled between the walls shown in the figure at a speed of 0.5 m/s. Note that the space that is not occupied by the plate is filled with glycerin at a temperature of 20°C. Also, the plate is positioned midway between the walls. Sketch the velocity distribution of the glycerin at section A-A. Neglecting the weight of the plate, estimate the fo
Answer Preview: To estimate the force required to pull the plate at the given speed and determine the velocity distr…

, Chapter: 4 -Problem: 46 >> Kerosene at 20°C flows through a contraction section as shown. A pressure gage connected between the upstream pipe and throat section shows a pressure difference of 25 kPa. The gasoline velocity in the throat section is 8.7 m/s. What is the velocity (m/s) in the upstream pipe? Transcribed Image Text:
Answer Preview: The velocity in the upstream pipe can be calculated using the Bernoulli equation T…

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, Chapter: 14 -Problem: 21 >> An axial-flow blower is used for a wind tunnel that has a test section measuring 60 cm by 60 cm and is capable of airspeeds up to 40 m/s. If the blower is to operate at maximum efficiency at the highest speed and if the rotational speed of the blower is 2000 rpm at this condition, what are the diameter of the blower and the power required? Assume that the blower has the characteristics shown in Fi
Answer Preview: 2 2 To determine the diameter of the blower and the power required for a wind tunnel we will use the following steps Convert the test section dimensio…

, Chapter: 10 -Problem: 43 >> A pipe can be used to measure the viscosity of a fluid. A liquid flows in a 1.7-cm smooth pipe 0.52 m long with an average velocity of 8 m/s. A head loss of 5 cm is measured. Estimate the kinematic viscosity.
Answer Preview: HEAD LOSS IN PIPE FLOW IS GIVEN BY H 32 U L g D 2 …

, Chapter: 4 -Problem: 35 >> What pressure gradient is required to accelerate water (? = 1000 kg/m3) in a horizontal pipe at a rate of 7.7 m/s2?
Answer Preview: Given data The density of water 1000 kg m 3 Acceleration …

, Chapter: 5 -Problem: 38 >> What is the purpose of the Reynolds transport theorem?
Answer Preview: In fluid mechanics it is often more convenient to work with control …

, Chapter: 14 -Problem: 30 >> If a pump with the characteristics given in Fig. 14.10 is operated at a speed of 30 rps, what will be the shutoff head? Transcribed Image Text: 250 100 Efficiency 200 80 Power input, kW 150 Head (?? , m. 100 40 50 20 N = 2133.5 rpm n = 35.6 rps D = 37.1 cm 0.05 0.10 0.15 0.20 0.25 Discharge, m/s Hea
Answer Preview: To find the shutoff head of the pump we need to first understand what shutoff head means Shutoff hea…

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, Chapter: 5 -Problem: 55 >> A mechanical pump is used to pressurize a bicycle tire. The in flow to the pump is 0.4 cfm. The density of the air entering the pump is 0.075 lbm/ft3. The inflated volume of a bicycle tire is 0.050 ft3. The density of air in the inflated tire is 0.4 lbm/ft3. How many seconds does it take to pressurize the tire if there initially was no air in the tire?
Answer Preview: air that needs to be added to the tire and the mass flow rate of air entering the pump Given …

, Chapter: 15 -Problem: 19 >> How are head loss and slope related for nonuniform flow, as compared to uniform flow?
Answer Preview: In uniform flow head loss is directly proportional to t…

, Chapter: 3 -Problem: 90 >> The hydrometer shown weighs 0.015 N. If the stem sinks 7.2 cm in oil (z = 7.2 cm), what is the specific gravity of the oil?
Answer Preview: To find the specific gravity of the oil we can use the formula for buoyancy force F buoyan…

, Chapter: 10 -Problem: 53 >> Water (60°F) is pumped from a reservoir to a large, pressurized tank as shown. The steel pipe is 4 in. in diameter and 300 ft long. The discharge is 1 cfs. The initial water levels in the tanks are the same, but the pressure in tank B is 10 psig, and tank A is open to the atmosphere. The pump efficiency is 90%. Find the power necessary to operate the pump for the given conditions.
Answer Preview: To find the power necessary to operate the pump we can use the formula Power Flow Rate x Tot…

, Chapter: 4 -Problem: 61 >> Water in a flume is shown for two conditions. If the depth d is the same for each case, will gage A read greater or less than gage B? Explain. Transcribed Image Text: d A Pressure gage (a) V = 3 m/s d Pressure gage B (b)
Answer Preview: Assuming that the depth d is the same for both cases …

, Chapter: 6 -Problem: 12 >> This tank provides a water jet (70°F) to cool a vertical metal surface during manufacturing. Calculate V when a horizontal force of 180 lbf is required to hold the metal surface in place. Q = 3 cfs.
Answer Preview: Given data Horizontal force F 180 lbf Q 3 cfs …

, Chapter: 14 -Problem: 52 >> For a given Francis turbine, ?1 = 60°, ?2 = 90°, r1 = 5 m, r2 = 3 m, and B = 1 m. Th e discharge is 126 m3/s, and the rotational speed is 60 rpm. Assume T = 10°C.a. What should ?1 be for a non separating flow condition at the entrance to the runner?b. What is the maximum attainable power with the conditions noted?c. If you were to redesign the turbine blades of the runner, what changes would you s
Answer Preview: a In order to determine the value of 1 for a non separating flow condition at the entrance to the ru…

, Chapter: 14 -Problem: 10 >> A propeller 2 m in diameter, like the one for which characteristics are given in Fig. 14.3, is to be used on a swamp boat and is to operate at maximum efficiency when cruising. If the cruising speed is to be 40 km/h, what should the angular speed of the propeller be? Transcribed Image Text: 0.06 60
Answer Preview: The angular speed of the propeller can be calculated using the equation for the advance velocity of …

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, Chapter: 5 -Problem: 93 >> What is cavitation? Why does the tendency for cavitation in a liquid increase with increased temperatures?
Answer Preview: Cavitation is the phenomenon in which the pressure of the …

, Chapter: 14 -Problem: 61 >> A windmill is connected directly to a mechanical pump that is to pump water from a well 10 ft deep as shown. The windmill is a conventional horizontal-axis type with a fan diameter of 10 ft. The efficiency of the mechanical pump is 80%. The density of the air is 0.07 lbm/ft 3. Assume the windmill delivers the maximum power available. There is 20 ft of 2 in. galvanized pipe in the system. What woul
Answer Preview: To calculate the discharge of the pump we first need to calculate the power available from the windm…

, Chapter: 13 -Problem: 59 >> An engineer is designing a triangular weir for measuring the flow rate of a stream of water that has a discharge of 6 cfm. The weir has an included angle of 45° and a coefficient of discharge of 0.6. Find the head on the weir.
Answer Preview: A weir is a structure that is used to measure the flow rate of a stream of water by measur…

, Chapter: 10 -Problem: 16 >> Flow of a liquid in a smooth 3 cm pipe yields a head loss of 2 m per meter of pipe length when the mean velocity is 1 m/s. Calculate f and the Reynolds number. Prove that doubling the flow rate will double the head loss. Assume fully developed flow.
Answer Preview: The head loss in a pipe can be described by the Darcy Weisbach equation which states that the head l…

, Chapter: 4 -Problem: 53 >> A Pitot-static tube is used to measure the velocity at the center of a 12 in. pipe. If kerosene at 68°F is flowing and the deflection on a mercury-kerosene manometer connected to the Pitot tube is 5.5 in., what is the velocity?
Answer Preview: Thus mercury is highly dense liquid than water and kerosene It has less free flowi…

, Chapter: 5 -Problem: 45 >> Air is pumped into one end of a tube at a certain mass flow rate. Is it necessary that the same mass flow rate of air comes out the other end of the tube? Explain.
Answer Preview: It is not necessary that same mass flow rate cames out because …

, Chapter: 15 -Problem: 56 >> Water flows uniformly at a depth y1 = 32 cm in the concrete channel shown, which is 8 m wide. Estimate the height of the hydraulic jump that will form when a sill is installed to force it to form. Assume Manning’s n value is n = 0.012. Transcribed Image Text: Slope = 0.040
Answer Preview: The height of the hydraulic jump that will form when a sill is installed to force it to form …

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, Chapter: 10 -Problem: 39 >> Water (20°C) flows in a 35-cm cast iron pipe at a rate of 0.5 m3/s. For these conditions, determine or estimate the following: a. The Reynolds number b. Friction factor f (use Swamee-Jain Eq. (10.39) in §10.6.) c. Shear stress at the wall, ?0
Answer Preview: a The Reynolds number can be calculated using the following equation Re u D Where u is …

, Chapter: 5 -Problem: 54 >> A tank has a hole in the bottom with a cross-sectional area of 0.0025 m2 and an inlet line on the side with a cross-sectional area of 0.0025 m2, as shown. The cross-sectional area of the tank is 0.1 m2. The velocity of the liquid flowing out the bottom hole is V = ?2gh, where h is the height of the water surface in the tank above the outlet. At a certain time, the surface level in the tank is 1 m
Answer Preview: Given Area of tank A t 0 1 m 2 Inlet cross section area A 1 0 0025 m 2 Cr…

, Chapter: 14 -Problem: 48 >> A penstock 1 m in diameter and 10 km long carries water at 10°C from a reservoir to an impulse turbine. If the turbine is 85% efficient, what power can be produced by the system if the upstream reservoir elevation is 650 m above the turbine jet and the jet diameter is 16.0 cm? Assume that f = 0.016 and neglect head losses in the nozzle. What should the diameter of the turbine wheel be if it is to
Answer Preview: First we can calculate the flow rate of the water using the equation Q A v where A is the …

, Chapter: 13 -Problem: 58 >> The head on a 60° triangular weir is 1.8 ft . What is the discharge of water over the weir?
Answer Preview: The discharge of water over the weir is 1 8 ft 3 s This c…

, Chapter: 10 -Problem: 27 >> Velocity measurements are made in a 35-cm pipe. The velocity at the center is found to be 2 m/s, and the velocity distribution is observed to be parabolic. If the pressure drop is found to be 2 kPa per 100 m of pipe, what is the kinematic viscosity ? of the fluid? Assume that the fluid’s SG = 0.8.
Answer Preview: The velocity distribution in a pipe is given by the equation u r u max 1 r R 2 Where u r is the velo…

, Chapter: 5 -Problem: 12 >> The hypothetical velocity distribution in a circular duct is where r is the radial location in the duct, R is the duct radius, and V0 is the velocity on the axis. Find the ratio of the mean velocity to the velocity on the axis. Transcribed Image Text: V =1 - Vo
Answer Preview: Let V r and V m denote velocity at radial location r in duct and mean velocity respective…

, Chapter: 14 -Problem: 56 >> What determines the minimum and maximum wind speeds at which a wind turbine can operate?
Answer Preview: Wind turbines require a minimum wind speed generally 12 14 km h to begin turning and g…

, Chapter: 14 -Problem: 9 >> If the tip speed of a propeller is to be kept below 0.8c, where c is the speed of sound, what is the maximum allowable angular speed of propellers having diameters of 2 m, 3 m, and 4 m? Take the speed of sound as 335 m/s.
Answer Preview: The tip speed of a propeller is the speed at the outermost point of the propeller bla…

, Chapter: 9 -Problem: 25 >> A liquid (? = 1000 kg/m3; ? = 2 × 10–2 N?s/m2; v = 2 × 10–5 m2/s) flows tangentially past a flat plate. If the approach velocity is 1 m/s, what is the liquid velocity 2 m downstream from the leading edge of the plate, at 0.8 mm away from the plate?
Answer Preview: Calculating Reynold s number for laminar flow Vol …

, Chapter: 5 -Problem: 62 >> Two pipes, A and B, are connected to an open water tank. The water is entering the bottom of the tank from pipe A at 10 cfm. The water level in the tank is rising at 1.0 in./min, and the surface area of the tank is 80 ft 2. Calculate the discharge in a second pipe, pipe B, that is also connected to the bottom of the tank. Is the flow entering or leaving the tank from pipe B?
Answer Preview: To calculate the discharge in pipe B we need to know the flow rate in pipe A the rate of change of t…

, Chapter: 4 -Problem: 13 >> In the system in the figure, the valve at C is gradually opened in such a way that a constant rate of increase in discharge is produced. How would you classify the flow at B while the valve is being opened? How would you classify the flow at A? Transcribed Image Text: A B
Answer Preview: Energy presents in the form of pressure velocity and e…

, Chapter: 9 -Problem: 13 >> Uniform, steady flow is occurring between horizontal parallel plates as shown.a. In a few words, tell what other condition must be present to cause the odd velocity distribution.b. Where is the minimum shear stress located?
Answer Preview: a In a few words tell what other condition must be …

, Chapter: 5 -Problem: 26 >> Water flows through a 4.0 in. diameter pipeline at 75 lbm/min. Calculate the mean velocity. Assume T = 60°F.
Answer Preview: To calculate the mean velocity of the water flowing through the pipeline we need to …

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, Chapter: 10 -Problem: 44 >> For a 40 cm pipe, the resistance coefficient f was found to be 0.06 when the mean velocity was 3 m/s and the kinematic viscosity was 10–5 m2/s. If the velocity were doubled, would you expect the head loss per meter of length of pipe to double, triple, or quadruple?
Answer Preview: Ans We have given the followings in the question Diameter of pipe D 40 cm 0 4 m Resistance coeff…

, Chapter: 5 -Problem: 86 >> Venturi-type applicators are frequently used to spray liquid fertilizers. Water flowing through the venturi creates a sub atmospheric pressure at the throat, which in turn causes the liquid fertilizer to flow up the feed tube and mix with the water in the throat region. The venturi applicator shown uses water at 20°C to spray a liquid fertilizer with the same density. The venturi exhausts to the a
Answer Preview: In order to find the flow rate of liquid fertilizer in the feed tube Ql and the concentration of liquid fertilizer in the mixture we can use the Berno…

, Chapter: 14 -Problem: 15 >> The pump used in the system shown has the characteristics given in Fig. 14.8. What discharge will occur under the conditions shown, and what power is required? Transcribed Image Text: 100 10 80 Power Efficiency 60 40 ?ead 20 N = 690 rpm n= 11.5 rps D = 35.6 cm 0.05 0.10 0.15 0.20 0.25 0.30 Discharg
Answer Preview: Based on the pump curve in Fig 14 8 we need to find the discharge and power required for the given c…

, Chapter: 8 -Problem: 61 >> A tidal estuary is to be modeled at 1/600 scale. In the actual estuary, the maximum water velocity is expected to be 3.6 m/s, and the tidal period is approximately 12.5 h. What corresponding velocity and period would be observed in the model?
Answer Preview: In the model the maximum water velocity would be 0 006 m s and the tidal period would be a…

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, Chapter: 3 -Problem: 72 >> A plug in the shape of a hemisphere is inserted in a hole in the side of a tank as shown in the figure. The plug is sealed by an O-ring with a radius of 0.2 m. The radius of the hemispherical plug is 0.25 m. The depth of the center of the plug is 2 m in fresh water. Find the horizontal and vertical forces on the plug due to hydrostatic pressure.
Answer Preview: given data Diameter of hemisphere D 0 25 m the distance from the water surface to the …

, Chapter: 10 -Problem: 52 >> The house shown is flooded by a broken waterline. The owners siphon water out of the basement window and down the hill, with one hose, of length L, and thus an elevation difference of h to drive the siphon. Water drains from the siphon, but too slowly for the desperate home owners. They reason that with a larger head difference, they can generate more flow. So they get another hose, same length as
Answer Preview: a The flow rate for a siphon is determined by the height difference h and the length …

, Chapter: 5 -Problem: 15 >> In Problem 5.14, if Vmax = 8 m/s, Vmin = 6 m/s, and D = 2 m, what is the discharge in cubic meters per second and the mean velocity? Data from Problem 5.14,Water flows in a pipe that has a 4 ft diameter and the following hypothetical velocity distribution: The velocity is maximum at the centerline and decreases linearly with r to a minimum at the pipe wall. If Vmax = 15 ft /s and Vmin = 9 ft /s, w
Answer Preview: The discharge in cubic meters per second and the mean veloc…

, Chapter: 14 -Problem: 13 >> Answer the following questions about axial-flow pumps. a. Axial-flow pumps are best suited for what conditions of head produced and discharge?b. For an axial-flow pump, how does the head produced by the pump and the power required to operate a pump vary with flow rate through the pump?
Answer Preview: a Axial flow pumps are best suited for low head and high discharge conditions They are eff…

, Chapter: 9 -Problem: 7 >> The upper plate shown is moving to the right with a velocity V, and the lower plate is free to move laterally under the action of the viscous forces applied to it. For steady-state conditions, derive an equation for the velocity of the lower plate. Assume that the area of oil contact is the same for the upper plate, each side of the lower plate, and the fixed boundary.
Answer Preview: lets assume V lower be the velocity of lower plate Our a…

, Chapter: 6 -Problem: 20 >> A conveyor belt discharges gravel into a barge as shown at a rate of 40 yd3/min. If the gravel weighs 120 lbf/ft 3, what is the tension in the hawser that secures the barge to the dock? Transcribed Image Text: Conveyor belt V = 15 ft/s Gravel 20° Hawser, Barge Dock
Answer Preview: To determine the tension in the hawser that secures the barge to the dock we need to calcula…

, Chapter: 3 -Problem: 74 >> Three spheres of the same diameter are submerged in the same body of water. One sphere is steel, one is a spherical balloon filled with water, and one is a spherical balloon filled with air.a. Which sphere has the largest buoyant force?b. If you move the steel sphere from a depth of 1 ft to 10 ft, what happens to the magnitude of the buoyant force acting on that sphere?c. If all three spheres are
Answer Preview: a The buoyant force on an object submerged in a fluid is equal to the weight of the fluid that the o…

, Chapter: 10 -Problem: 49 >> Air flows in a 3-cm smooth tube at a rate of 0.015 m3/s. If T = 20°C and p = 110 kPa absolute, what is the pressure drop per meter of length of tube?
Answer Preview: Air flows in a 3 cm smooth tube at a rate of 0 015 m 3 s If T 20C and …

, Chapter: 5 -Problem: 34 >> State whether each of the following quantities is extensive or intensive:a. Massb. Volumec. Densityd. Energye. Specific energy
Answer Preview: An extensive property is a physical quantity whose value is proportional to the size of the system …

, Chapter: 3 -Problem: 82 >> A block of material of unknown volume is submerged in water and found to weigh 390 N (in water). The same block weighs 700 N in air. Determine the specific weight and volume of the material.
Answer Preview: Given data Weight of block in water 390 N weight of block in air 700N Sol…

, Chapter: 7 -Problem: 20 >> For this system, the discharge of water is 0.2 m3/s, x = 1.0 m, y = 1.5 m, z = 6.0 m, and the pipe diameter is 60 cm. Assuming a head loss of 0.5 m, what is the pressure head at point 2 if the jet from the nozzle is 10 cm in diameter? Assume ? = 1.0 at all locations.
Answer Preview: The pressure head at point 2 can be found using the Bernoulli equation which states that the pressur…

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, Chapter: 14 -Problem: 17 >> For a pump with the characteristics given in Fig. 14.7 or 14.8, what water discharge and head will be produced at maximum efficiency if the pump diameter is 20 in. and the angular speed is 1100 rpm? What power is required under these conditions?In Fig 14.8Fig 14.7 Transcribed Image Text: 100 10 80 P
Answer Preview: To determine the water discharge and head produced at maximum efficiency and the power required for …

, Chapter: 12 -Problem: 22 >> A shock wave occurs in a methane stream in which the Mach number is 3, the static pressure is 89 kPa absolute, and the static temperature is 20°C. Determine the downstream Mach number, static pressure, static temperature, and density.
Answer Preview: The pressure and temperature of the air at the inlet to the duct are 100 kPa and 10C respecti…

, Chapter: 5 -Problem: 85 >> The annular venturi meter is useful for metering flows in pipe systems for which upstream calming distances are limited. The annular venturi meter consists of a cylindrical section mounted inside a pipe as shown. The pressure difference is measured between the upstream pipe and at the region adjacent to the cylindrical section. Air at standard conditions flows in the system. The pipe diameter is 6
Answer Preview: The volume flow rate can be determined using the Bernoulli equation which relates the pressure veloc…

, Chapter: 14 -Problem: 33 >> Answer the following questions regarding pump sizing and selection.a. What is the difference between a system curve and a pump curve? Explain.b. The operating point for a pump system is established by what condition?
Answer Preview: a A system curve is a graph that shows the relationship between the flow rate and the head press…

, Chapter: 6 -Problem: 91 >> A reducing pipe bend is held in place by a pedestal as shown. There are expansion joints at sections 1 and 2, so no force is transmitted through the pipe past these sections. The pressure at section 1 is 20 psig, and the rate of flow of water (? = 62.4 lbm/ft 3) is 2 cfs. Find the force and moment that must be applied at section 3 to hold the bend stationary. Assume the flow is irrotational, and n
Answer Preview: To find the force and moment required to hold the bend stationary at section 3 we need to consider t…

, Chapter: 5 -Problem: 88 >> An atomizer utilizes a constriction in an air duct as shown. Design an operable atomizer making your own assumptions regarding the air source. Transcribed Image Text: Air source Water HH
Answer Preview: Designing an operable atomizer involves creating a device that can effectively break down a liquid into fine droplets and disperse them into the surrounding air Atomizers are used in various applicati…

, Chapter: 4 -Problem: 19 >> For a rotating body, is the acceleration toward the center of rotation a centripetal or centrifugal acceleration? Justify your answer. You may also want to look up word meanings and word roots.
Answer Preview: The cent rip et al acceleration is the acceleration that is directed toward the …

, Chapter: 9 -Problem: 24 >> Which of the following are features of a laminar boundary layer? (Select all that are correct.)a. Flow is smooth.b. The boundary layer thickness increases in the downstream direction.c. A decreasing boundary layer thickness correlates with decreasing shear stress.d. An increasing boundary layer thickness correlates with decreasing shear stress.
Answer Preview: a Flow is smooth b The boundary layer thickness increases in the downs…

, Chapter: 5 -Problem: 84 >> The flow pattern through the pipe contraction is as shown, and the Q of water is 60 cfs. For d = 2 ft and D = 6 ft , what is the pressure at point B if the pressure at point C is 3200 psf? Transcribed Image Text: C E d 20° D B A.
Answer Preview: Given data Q of water 60 cFs d 2ft d 6ft A 6 Ac Pc 3200 psf PB We know that at point c AB 2 m …

, Chapter: 3 -Problem: 79 >> An 800 ft ship has a weight of 40,000 tons, and the area defined by the waterline is 38,000 ft2. Will the ship take more or less draft when steaming from salt water to fresh water? How much will it settle or rise?
Answer Preview: The density of salt water is typically about 1 025 g cm3 while the …

, Chapter: 9 -Problem: 19 >> Two vertical parallel plates are spaced 0.012 ft apart. If the pressure decreases at a rate of 100 psf/ft in the vertical z direction in the fluid between the plates, what is the maximum fluid velocity in the z direction? The fluid has a viscosity of 10–3 lbf?s/ft 2 and a specific gravity of 0.80.
Answer Preview: The maximum fluid velocity in the z direction can be calculated using the equation of motion …

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, Chapter: 4 -Problem: 12 >> Which is the most correct way to characterize turbulent flow?a. 1-Db. 2-Dc. 3-D
Answer Preview: c 3 D Turbulent flow is characterized as a three dimensional fl…

, Chapter: 10 -Problem: 33 >> liquid flows in a round pipeline. The mass flow rate is 9800 kg/s. The Reynolds number is 6 million. Kinematic viscosity is 1.4E-6 m2/s and SG = 0.9. Calculate the pipe diameter in meters. Choose the closest answer (m): (a) 0.8, (b) 1.1, (c) 1.4, (d) 1.7,(e) 2.0.
Answer Preview: Density rho mass Volume Here S G 0 9 Therefore Density of liquid …

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, Chapter: 5 -Problem: 18 >> The rectangular channel shown is 1.2 m wide. What is the discharge in the channel? Transcribed Image Text: Vertical depth = 1m 1/3 u = y"3 m/s Water 30°
Answer Preview: b 1 2 m From fig vertical length 1 m Let depth in y dir…

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, Chapter: 9 -Problem: 4 >> A board 1 m by 1 m that weighs 55 N slides down an inclined ramp with a velocity of 40 cm/s. The board is separated from the ramp by a layer of oil 0.6 mm thick. Neglecting the edge effects of the board, calculate the dynamic viscosity ? of the oil.
Answer Preview: To solve this problem first of all inclination angle of ramp is not given and not given ot…

, Chapter: 5 -Problem: 51 >> In a food-drying facility, a constant-diameter heated pipe is used to raise the temperature of air. At the pipe entrance, the velocity is 12 m/s, the pressure is 100 kPa absolute, and the temperature is 20°C. At the outlet, the pressure is 90 kPa absolute and the temperature is 80°C. What is the velocity at the outlet? Can the Bernoulli equation be used to relate the pressure and velocity changes?
Answer Preview: To determine the velocity at the outlet we need to know the properties of the air at the entrance an…

, Chapter: 16 -Problem: 11 >> Consider water draining out of round hole in the bottom of a round tank. Assume constant density and also assume that the water does not swirl. Then,a. Select the general form of the continuity equation that best applies to this problem, andb. Show how to simplify the general equation from part (a) to develop the reduced form.
Answer Preview: Consider water draining out of a round hole in the bottom of a round tank Ass…

, Chapter: 4 -Problem: 14 >> Water flows in the passage shown. If the flow rate is decreasing with time, the flow is classified as (a) Steady, (b) Unsteady,(c) Uniform, or (d) Nonuniform. (Select all that apply.)
Answer Preview: b Unsteady A flow is classified as Steady if the fluid properties velocity p…

, Chapter: 10 -Problem: 56 >> A plastic siphon hose of length 7 m is used to drain water (15°C) out of a tank. For a flow rate of 1.5 L/s, what hose diameter is needed? Use H = 5 m and h = 0.5 m. Assume all head loss occurs in the tube. Transcribed Image Text: Siphon hose diameter D h Water (T = 15°C)
Answer Preview: Given Q 1 5 l s 1 5 x 10 3 m 3 s L 7m h 0 5m H 5m To find diameter d of the hose …

, Chapter: 5 -Problem: 44 >> Water flows through a full pipe. Is it possible for the volume flow rate into the pipe to be different than the flow rate out of the pipe? Explain.
Answer Preview: The volume flow rate of a fluid is defined as the volume of fluid that is passing through th…

, Chapter: 16 -Problem: 8 >> Compare and contrast the integral form of the continuity equation [(Eq. (5.28)] with the PDE form of the continuity equation [(Eq. (16.36)]. Address the following questions.a. Are the units and dimensions of each term the same? Or different?b. How do the physics compare? What is the same? What is different?c. How do the derivations compare? What is the same? What is different?d. When would you wan
Answer Preview: a The units and dimensions of each term in the integral form of the continuity equation Eq 5 28 and …

, Chapter: 14 -Problem: 22 >> An axial-flow blower is used to air-condition an office building that has a volume of 105 m3. It is decided that the air at 60°F in the building must be completely changed every 15 min. Assume that the blower operates at 600 rpm at maximum efficiency and has the characteristics shown in Fig. 14.7. Calculate the diameter and power requirements for two blowers operating in parallel.
Answer Preview: The dimensionless parameters are given by Capacity coefficient C Q C Q V wd 3 Here Flow …

, Chapter: 10 -Problem: 69 >> A pump is used to fill a tank from a reservoir as shown. The head provided by the pump is given by hp = h0(l–Q2/Q2 max)) where h0 is 50 meters, Q is the discharge through the pump, and Qmax is 2 m3/s. Assume f = 0.018 and the pipe diameter is 90 cm. Initially the water level in the tank is the same as the level in the reservoir. The cross-sectional area of the tank is 100 m2. How long will it take
Answer Preview: Solution Head loss coefficient for Entry 0 5 Exit 1 Friction …

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, Chapter: 15 -Problem: 20 >> Is critical flow a desirable or undesirable flow condition? Why?
Answer Preview: Critical flow is an undesirable flow condition because it is associated with a sudden uncon…

, Chapter: 4 -Problem: 9 >> Identify five examples of an unsteady flow and explain what features classify them as an unsteady flow.
Answer Preview: Passage of a Flood Wave Operation of Irrigation and Power Canals Tidal …

, Chapter: 10 -Problem: 8 >> The head loss from section 1 to 2 is 1.0 m. The Darcy friction factor is 0.01. D = 1.0 m. L = 100 m. The flow is steady and fully developed. Calculate the mean velocity in m/s. Choose the closest answer (m/s): (a) 1.2,(b) 2.4, (c) 3.2, (d) 4.4, (e) 5.6. Transcribed Image Text: 2.
Answer Preview: Let f friction factor d diameter of pipe L length of pipe v mean velocity h f head loss …

, Chapter: 6 -Problem: 9 >> A water jet of diameter 40 mm and speed v = 20 m/s is filling a tank. The tank has a mass of 23 kg and contains 28 liters of water at the instant shown. The water temperature is 15°C. Find the force acting on the bottom of the tank and the force acting on the stop block. Neglect friction. Transcribed Image Text:
Answer Preview: Step 1 …

, Chapter: 15 -Problem: 11 >> Determine the discharge in a 5 ft diameter smooth (troweled) concrete sewer pipe on a slope of 0.001 that is carrying water at a depth of 4 ft.
Answer Preview: To determine the discharge in a pipe we can use the Manning equation V 1 n R 2 3 S 1 2 where V is th…

, Chapter: 4 -Problem: 10 >> You are pouring a heavy syrup on your pancakes. As the syrup spreads over the pancakes, would the thin film of syrup be a laminar or turbulent flow? Why?
Answer Preview: when we will pour a thick liquid …

, Chapter: 10 -Problem: 70 >> A water turbine is connected to a reservoir as shown. The flow rate in this system is 4 cfs. What power can be delivered by the turbine if its efficiency is 90%? Assume a temperature of 70°F. Transcribed Image Text: Steel pipe d= 12 in. 100 ft L= 1000 ft
Answer Preview: Given data Flow rate Q 4 cfs 0 1132m sec Diametre D 12 inch 0 3048m Head available H …

, Chapter: 6 -Problem: 74 >> For laminar flow in a pipe, wall shear stress (?0) causes the velocity distribution to change from uniform to parabolic as shown. At the fully developed section, the velocity profile is u = umax[1 – (r/r0)2]. Derive a formula for the force on the wall due to shear stress, F?, between 1 and 2 as a function of U (the mean velocity in the pipe), ?, p1, p2, and D (the pipe diameter).
Answer Preview: The force on the wall due to shear stress F between 1 and 2 can be derived as follows First the wall …

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, Chapter: 3 -Problem: 96 >> A cylindrical block of wood 1 m in diameter and 1 m long has a specific weight of 7500 N/m3. Will it float in water with its axis vertical?
Answer Preview: The block of wood will float in water with its axis vertical The …

, Chapter: 8 -Problem: 16 >> A solid particle falls through a viscous fluid. The falling velocity, V, is believed to be a function of the fluid density, ?f, the particle density, ?p, the fluid viscosity, ?, the particle diameter, D, and the acceleration due to gravity, g:V = f (?f , ?p,?, D, g)By dimensional analysis, develop the ?-groups for this problem. Express your answer in the form
Answer Preview: V k f p D g where k is a dimensionless constant an…

, Chapter: 5 -Problem: 21 >> Engineers are developing a new design of a jet engine for an unmanned aerial vehicle (i.e., a drone). During testing, to simulate flight, air is supplied to the jet engine through an attached round duct. In the duct, just upstream of the jet engine, the following specifications are required: V = 280 m/s, m· = 180 kg/s, p = 60 kPa abs, and T = –17°C. What diameter pipe is needed to meet these specs
Answer Preview: To determine the diameter of the pipe needed to meet the specified velocity mass flow rate pressure …

, Chapter: 15 -Problem: 63 >> Consider the hydraulic jump shown for the long horizontal rectangular channel. What kind of water-surface profile (classification) is located upstream of the jump? What kind of water-surface profile is located downstream of the jump? If baffle blocks are put on the bottom of the channel in the vicinity of A to increase the bottom resistance, what changes are likely to occur given the same gate ope
Answer Preview: Consider the hydraulic jump shown for the long horizontal rectangular channel What kind of wa…

, Chapter: 4 -Problem: 21 >> The flow passing through a nozzle is steady. The speed of the fluid increases between the entrance and the exit of the nozzle. The acceleration halfway between the entrance and the nozzle isa. Convectiveb. Localc. Both
Answer Preview: a Convective The speed of the fluid increases between the entrance and the exit of the …

, Chapter: 10 -Problem: 46 >> A fluid flows through a pipe. Calculate the drop in piezometer level (?h) in units of cm. The flow is steady and fully developed. The fluid is Newtonian. The mean velocity is 0.4 m/s. The Reynolds number is 100,000. The relative roughness is 0.002. The length between piezometers is 50 m and the pipe ID is 3.0 cm. Choose the closest answer (cm): (a) 8, (b) 14, (c) 22,(d) 28, (e) 34.
Answer Preview: The drop in piezometer level h can be calculated using the Darcy Weisbach eq…

, Chapter: 6 -Problem: 5 >> Give five examples of jets and how they occur in practice.
Answer Preview: Moving fluid in natural or artificial systems may exert forces on objects in contact with it To anal…

, Chapter: 14 -Problem: 46 >> A water-cooled centrifugal compressor is used to compress air from 100 kPa to 600 kPa at the rate of 2 kg/s. The temperature of the inlet air is 15°C. Th e efficiency of the compressor is 50%. Calculate the necessary shaft power.
Answer Preview: To calculate the necessary shaft power for a water cooled centrifugal compressor we first need to ca…

, Chapter: 13 -Problem: 53 >> At one end of a rectangular tank 1 m wide is a sharp-crested rectangular weir 1 m high. In the bottom of the tank is a 10 cm sharp-edged orifice. If 0.10 m3/s of water flows into the tank and leaves the tank both through the orifice and over the weir, what depth will the water in the tank attain?
Answer Preview: At one end of a rectangular tank 1 m wide is a sharp crested re…

, Chapter: 10 -Problem: 41 >> Determine the head loss in 800 ft of a concrete pipe with a 6 in. diameter (ks = 0.0002 ft ) carrying 2.5 cfs of fluid. The properties of the fluid are ? = 3.33 × 10–3 ft 2/s and ? = 1.5 slug/ft 3.
Answer Preview: The head loss in 800 ft of a 6 in concrete pipe carrying …

, Chapter: 5 -Problem: 42 >> The law of conservation of mass for a closed system requires that the mass of the system isa. Constantb. Zero
Answer Preview: Well as per Law of conservation of mass for a closed system when t…

, Chapter: 14 -Problem: 51 >> Answer the following questions about reaction turbines.a. How does a reaction turbine differ from a centrifugal pump?b. What is meant by the “runner” in a reaction turbine?
Answer Preview: a A reaction turbine differs from a centrifugal pump in the way they convert energy A centrifugal pu…

, Chapter: 13 -Problem: 57 >> Water flows from the first reservoir to the second over a rectangular weir with a width-to-head ratio of 3. The height P of the weir is twice the head. The water from the second reservoir flows over a 60° triangular weir to a third reservoir. Th e discharge across both weirs is the same. Find the ratio of the head on the rectangular weir to the head on the triangular weir.
Answer Preview: The discharge Q across the rectangular weir is given …

, Chapter: 10 -Problem: 17 >> As shown, a round tube of diameter 0.5 mm and length 750 mm is connected to plenum. A fan produces a negative gage pressure of –1.5 inch H2O in the plenum and draws air (20°C) into the microchannel. What is the mean velocity of air in the microchannel? Assume that the only head loss is in the tube. Transcribed Image Text:
Answer Preview: The mean velocity of air in the microchannel can be calculated using the Berno…

, Chapter: 5 -Problem: 69 >> Oxygen and methane are mixed at 204 kPa absolute pressure and 100°C. The velocity of the gases into the mixer is 8 m/s. The density of the gas leaving the mixer is 2.2 kg/m3. Determine the exit velocity of the gas mixture. Transcribed Image Text: CH4 A =1 cm? A = 3 cm? A = 3 cm? O,
Answer Preview: Let s first calculate the mass flow rate of each gas into the mixer Since we know the velocity and the cross sectional area of each pipe we can use the equation m dot A v where m dot is the mass flow …

, Chapter: 15 -Problem: 21 >> Critical flow _____. (Select all of the following that are correct.)a. Occurs when specific energy is a minimum for a given discharge.b. Occurs when the discharge is maximum for a given specific energy.c. Occurs when Fr < 1.d. Occurs when Fr = 1.
Answer Preview: a Occurs when specific energy is a minimum for a given discharge d Occurs when Fr 1 Critical fl…

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, Chapter: 9 -Problem: 12 >> Uniform, steady flow is occurring between horizontal parallel plates as shown.a. The flow is Poiseuille; therefore, what is causing the fluid to move?b. Where is the maximum velocity located?c. Where is the maximum shear stress located?d. Where is the minimum shear stress located?
Answer Preview: a The flow is Poiseuille flow which is a type of laminar flow that occurs between para…

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, Chapter: 15 -Problem: 44 >> As waves in the ocean approach a sloping beach, they curve so that they are nearly parallel to the beach when they finally break (see accompanying figure). Explain why the waves curve like this. With a sloping beach, where is the water most shallow? Transcribed Image Text: Deep-water waves Wave dire
Answer Preview: When waves in the ocean approach a sloping beach they curv…

, Chapter: 3 -Problem: 77 >> As shown, a cube (L = 94 mm) suspended in carbon tetrachloride is exactly balanced by an object of mass m1 = 610 g. Find the mass m2 of the cube. Transcribed Image Text: Balance beam scale - Cube with mass m, Block with mass m, L Carbon tetrachloride
Answer Preview: The weight of the cube in air is equal to the buoyant force acting on it when it is submerged in car…

, Chapter: 10 -Problem: 66 >> Water will be siphoned through a 3/16-in.-diameter, 50 in. long Tygon tube from a jug on an upside-down wastebasket into a graduated cylinder as shown. The initial level of the water in the jug is 21 in. above the tabletop. The graduated cylinder is a 500 mL cylinder, and the water surface in the cylinder is 12 in. above the tabletop when the cylinder is full. The bottom of the cylinder is 1/2 in.
Answer Preview: In order to calculate the time it will take to fill the cylinder from an initial depth of 2 inches o…

, Chapter: 5 -Problem: 23 >> An empirical equation for the velocity distribution in a horizontal, rectangular, open channel is given by u = umax (y/d)n, where u is the velocity at a distance y meters above the floor of the channel. If the depth d of flow is 1.7 m, umax = 9 m/s, and n = 1/6, what is the discharge in cubic meters per second per meter of width of channel? What is the mean velocity?
Answer Preview: The discharge in cubic meters per second per meter of width of channel is …

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, Chapter: 4 -Problem: 2 >> Is the pattern produced by smoke rising from a chimney on a windy day analogous to a path line or a streak line? Explain based on the definition of each.
Answer Preview: The pattern produced by smoke rising from a chimney on a windy …

, Chapter: 10 -Problem: 22 >> Oil (SG = 0.94; ? = 0.048 N?s/m2) is pumped through a horizontal 10 cm pipe. Mean velocity is 0.3 m/s. What is the pressure drop per 10 m of pipe?
Answer Preview: According to Hagen Poiseuille s Formula circular pipe for laminar flow P 1 P 2 32 v L d 2 in …

, Chapter: 5 -Problem: 36 >> What is a control surface and a control volume? Can mass pass through a control surface?
Answer Preview: Control Volume Analysis Control volume is a volume …

, Chapter: 16 -Problem: 9 >> Start with the conservation form of the continuity equation in Cartesian coordinates and derive the non-conservation form.
Answer Preview: The conservation form of the continuity equation in Cartesian coordinates is given by t u 0 where is …

, Chapter: 3 -Problem: 91 >> The hydrometer shown sinks 4.7 cm (z = 4.7 cm) in water (15°C). Th e bulb displaces 1.0 cm3, and the stem area is 0.1 cm2. Find the weight of the hydrometer. Transcribed Image Text: A = 0.1 cm? +=1.0 cm
Answer Preview: To find the weight of the hydrometer we can use the formula for buoyancy force F buoyancy V de…

, Chapter: 10 -Problem: 25 >> Glycerine (T = 20°C) flows through a funnel with D = 1.3 cm as shown. Calculate the mean velocity of the glycerine exiting the tube. Assume the only head loss is due to friction in the tube. Transcribed Image Text: 30 cm 20 cm D
Answer Preview: To calculate the mean velocity of the glycerine exiting the tube we will follow these steps 1 Calcul…

, Chapter: 5 -Problem: 28 >> Water from a pipeline is diverted into a weigh tank for 15 min. The increased weight in the tank is 4765 lbf. What is the average flow rate in gallons per minute and in cubic feet per second? Assume T = 60°F.
Answer Preview: To calculate the average flow rate in gallons per minute and cubic feet per second we need to know t…

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, Chapter: 4 -Problem: 16 >> Correctly match the items in column A with those in column B. Transcribed Image Text: A B Steady flow Unsteady flow aVlds = 0 aVlds + 0 Uniform flow av,ldt + 0 Nonuniform flow av,ldt = 0
Answer Preview: Answer for the given question is matched correctly in the above table The e…

, Chapter: 12 -Problem: 26 >> The truncated nozzle shown in the figure is used to monitor the mass flow rate of methane. The area of the nozzle is 3 cm2, and the area of the pipe is 12 cm2. The upstream total pressure and total temperature are 150 kPa absolute and 30°C. The back pressure is 100 kPa. a. Calculate the mass flow rate of methane. b. Calculate the mass flow rate assuming the Bernoulli equation is valid, with the de
Answer Preview: Given Process constant k 1 31 Area of the …

, Chapter: 6 -Problem: 19 >> A jet of water (60°F) is discharging at a constant rate of 2.0 cfs from the upper tank. If the jet diameter at section 1 is 4 in., what forces will be measured by scales A and B? Assume the empty tank weighs 300 lbf, the cross-sectional area of the tank is 4 ft 2, h = 1 ft , and H = 9 ft .
Answer Preview: To determine the forces measured by scales A and B we would need to know the specific deta…

, Chapter: 15 -Problem: 3 >> Two channels have the same cross-sectional area, but different geometry, as shown.a. Which channel has the largest wetted perimeter?b. Which channel has more contact between water and channel wall?c. Which channel will have more energy loss to friction?
Answer Preview: a The channel with the rectangular cross section has the largest wetted perimeter b The channel wit…

, Chapter: 4 -Problem: 17 >> Classify each of the following as a one-dimensional, two–dimensional, or three-dimensional flow.a. Water flow over the crest of a long spillway of a dam.b. Flow in a straight horizontal pipe.c. Flow in a constant-diameter pipeline that follows the contour of the ground in hilly country.d. Airflow from a slit in a plate at the end of a large rectangular duct. Airflow past an automobile.f. Airflow p
Answer Preview: a Water flows over the crest of a long spillway of a dam two dimension…

, Chapter: 12 -Problem: 31 >> A wind tunnel using air is designed to have a Mach number of 3, a static pressure of 1.5 psia, and a static temperature of ?10°F in the test section. Determine the area ratio of the nozzle required and the reservoir conditions that must be maintained if air is to be used.
Answer Preview: To determine the area ratio of the nozzle required we can use the equation for the ideal gas flow th…

, Chapter: 5 -Problem: 13 >> Water flows in a two-dimensional channel of width W and depth D as shown in the diagram. The hypothetical velocity profile for the water is where Vs is the velocity at the water surface midway between the channel walls. The coordinate system is as shown; x is measured from the center plane of the channel and y downward from the water surface. Find the discharge in the channel in terms of Vs, D, an
Answer Preview: To find the discharge in the channel we need to integrate the velocity profile over the cr…

, Chapter: 15 -Problem: 15 >> A rectangular concrete channel 4 m wide on a slope of 0.004 is designed to carry a water (T = 10°C) discharge of 25 m3/s. Estimate the uniform flow depth for these conditions. The channel has a rectangular cross section, and the concrete is rough, unfinished.
Answer Preview: To estimate the uniform flow depth in the channel we can use the Manning s equation which relates th…

, Chapter: 3 -Problem: 94 >> A barge 20 ft wide and 40 ft long is loaded with rocks as shown. Assume that the center of gravity of the rocks and barge is located along the centerline at the top surface of the barge. If the rocks and the barge weigh 400,000 lbf, will the barge float upright or tip over? Transcribed Image Text: G
Answer Preview: St…

, Chapter: 12 -Problem: 21 >> A Pitot-static tube is used to measure the Mach number on a supersonic aircraft . The tube, because of its bluntness, creates a normal shock wave as shown. The absolute total pressure downstream of the shock wave (pt2) is 150 kPa. The static pressure of the free stream ahead of the shock wave (p1) is 40 kPa and is sensed by the static pressure tap on the probe. Determine the Mach number (M1) graph
Answer Preview: The given information is Absolute total pressure downstream of the shock wave pt2 150 kPa St…

, Chapter: 6 -Problem: 31 >> A horizontal jet of water (at 10°C) that is 6 cm in diameter and has a velocity of 20 m/s is deflected by the vane as shown. If the vane is moving at a rate of 7 m/s in the x-direction, what components of force are exerted on the vane by the water in the x-and y-directions? Assume negligible friction between the water and the vane. See §6.5 for useful knowledge about moving CV's.
Answer Preview: The force exerted by the water on the vane can be calculated using the principle of momentum conserv…

, Chapter: 15 -Problem: 29 >> The discharge in a trapezoidal channel is 10 m3/s. The bottom width of the channel is 3.0 m, and the side slopes are 1 vertical to 1 horizontal. If the depth of flow is 1.0m, is the flow supercritical or subcritical?
Answer Preview: The flow in the trapezoidal channel is supercritical This can be determined by c…

, Chapter: 4 -Problem: 6 >> At time t = 0, a dye streak was started at point A in a flow field of liquid. The speed of the flow is constant over a 10s period, but the flow direction is not necessarily constant. At any particular instant, the velocity in the entire field of flow is the same. The streak line produced by the dye is shown head. Draw (and label) a streamline for the flow field at t = 8 s. Draw (and label) a path
Answer Preview: Shown the origin of the streak line at point A as in fig a …

, Chapter: 11 -Problem: 61 >> The landing speed of an airplane is 7 m/s faster than its stalling speed. The lift coefficient at landing speed is 1.2, and the maximum lift coefficient (stall condition) is 1.4. Calculate both the landing speed and the stalling speed.
Answer Preview: We know that Landing speed stalling speed 7 m s We also know that the lift coefficie…

, Chapter: 16 -Problem: 7 >> Consider a flat horizontal plate that is infinite in size in both dimensions. Above the plate is a fluid of viscosity ?. The plate is at rest. Then, at time equals zero seconds, the plate is set in motion to the right with a constant velocity V acting to the right. Consider the velocity field in the fluid above the plate and simplify the general form of the velocity field by answering the followin
Answer Preview: a The u and w velocity components are nonzero while the v component is zero T…

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, Chapter: 12 -Problem: 35 >> A rocket nozzle has the configuration shown. The diameter of the throat is 4 cm, and the exit diameter is 8 cm. The half-angle of the expansion cone is 15°. Gases with a specific heat ratio of 1.2 flow into the nozzle with a total pressure of 250 kPa. The back pressure is 100 kPa. First, using an iterative or graphical method, determine the area ratio at which the shock occurs. Then determine the
Answer Preview: The area ratio Ae At is a measure of the expansion of the gases within the nozzle where Ae is the ex…

, Chapter: 15 -Problem: 40 >> A rectangular channel that is 10 ft wide is very smooth except for a small reach that is roughened with angle irons attached to the bottom. Water flows in the channel at a rate of 200 cfs and at a depth of 1.0 ft upstream of the rough section. Assume frictionless flow except over the roughened part, where the total drag of all roughness (all of the angle irons) is assumed to be 2000 lbf. Determine
Answer Preview: The depth of the water downstream of the rough section can be determined using the energy equation T…

, Chapter: 4 -Problem: 24 >> Tests on a sphere are conducted in a wind tunnel at an air speed of U0. The velocity of flow toward the sphere along the longitudinal axis is found to be u = –U0 (1 – r30/x3), where r0 is the radius of the sphere and x the distance from its center. Determine the acceleration of an air particle on the x-axis upstream of the sphere in terms of x, r0, and U0.
Answer Preview: To determine the acceleration of an air particle on the x axis upstream of the sphere we ca…

, Chapter: 11 -Problem: 62 >> The figure shows the pressure distribution for a Göttingen 387-FB lifting vane (19) when the angle of attack is 8°. If such a vane with a 20 cm chord were used as a hydrofoil at a depth of 70 cm, at what speed in 10°C freshwater would cavitation begin? Also, estimate the lift per unit of length of foil at this speed. Trans
Answer Preview: Cavitation would begin at a speed of approximately 5 7 m s or 20 5 km h The lift per unit of length …

, Chapter: 15 -Problem: 64 >> The steep rectangular concrete spillway shown is 4 m wide and 500 m long. It conveys water from a reservoir and delivers it to a free outfall. The channel entrance is rounded and smooth (negligible head loss at the entrance). If the water-surface elevation in the reservoir is 2 m above the channel bottom, what will the discharge in the channel be?
Answer Preview: The steep rectangular concrete spillway shown is 4 m wide and 500 m long It …

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, Chapter: 7 -Problem: 7 >> An engineer is considering the development of a small wind turbine (D = 1.25 m) for home applications. The design wind speed is 15 mph at T = 10°C and p = 0.9 bar. The efficiency of the turbine is ? = 20%, meaning that 20% of the kinetic energy in the wind can be extracted. Estimate the power in watts that can be produced by the turbine. Hint: In a time interval ?t, the amount of mass that flows t
Answer Preview: To estimate the power in watts that can be produced by the turbine we can use the formula Power Watt…

, Chapter: 15 -Problem: 28 >> Water flows uniformly at a rate of 320 cfs in a rectangular channel that is 12 ft wide and has a bottom slope of 0.005. If n is 0.014, is the flow subcritical or supercritical?
Answer Preview: The flow in the rectangular channel is subcritical This can be determined by calculating the Froude …

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, Chapter: 7 -Problem: 27 >> A minor artery in the human arm, diameter D = 1 cm, tapers gradually over a distance of 10 cm to a diameter of d = 0.8 cm. The blood pressure (gage) at diameter D is 110 mm Hg, and at d is 85 mm Hg. What is the head loss (m) that occurs over this distance if the blood (SG = 1.06) is moving with a flow rate of 20 cm3/s and the arm is being held horizontally? Idealize the flow in the artery as stead
Answer Preview: The head loss in this case can be calculated using the equation of continuity and the equation of en…

, Chapter: 15 -Problem: 39 >> Water flows with a velocity of 3 m/s in a rectangular channel 3 m wide at a depth of 3 m. What is the change in depth and in water-surface elevation produced when a gradual contraction in the channel to a width of 2.6 m takes place? Determine the greatest contraction allowable without altering the specified upstream conditions.
Answer Preview: The change in depth is 0 3 m and the change in water surface elevation is 0 1

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