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Chapter: 9 -Problem: 21 >> Beginning with the appropriate form of the Navier€“ Stokes equations, develop an equation in the appropriate coordinate system to describe the velocity of a fluid that is flowing in the annular space as shown in the figure. The fluid is Newtonian, and is flowing in steady, in-compressible, fully developed, laminar flow through an infinitely long vertical round pipe annulus of inner radius RIand ou
Answer Preview: Need to begin with zdirection NavierStokes equation in cylindrical coordinates Applying the assu…

, Chapter: 26 -Problem: 16 >> As part of a process to fabricate materials with ordered pore arrays, the diffusion-limited solvent etching process shown in the figure (next column) is used to remove a contaminant (solid solute A, lithium carbonate) from an array of pores within a slab. There are presently 16 cylindrical pores, each of 0.10 cm diameter and 0.5 cm depth, and the overall dimensions of the slab are 4.0 cm per side
Answer Preview: a. The total transfer rate of solute A can be calculated using Fick's law of diffusion. J = -D*(dcA/…

, Chapter: 26 -Problem: 7 >> Consider the €œdrug patch€ shown in Problem 26.4. The patch consists of a pure solid drug source mounted on top of a water-swollen polymer, which acts as a controlled diffusion barrier. The square patch is 4.0 cm × 4.0 cm. The bottom surface of the diffusion barrier is in direct contact with the skin. The desired amount of cumulative drug release is 0.02 µtmole after 10 hours. Independent experi
Answer Preview: A drug B waterswollen polymer Estimate drug …

, Chapter: 20 -Problem: 29 >> An electric light bulb rated at 60 W has a surface temperature of 145°C when cooled by atmospheric air at 25°C. The air flows past the bulb with a velocity of 0.5 m/s. The bulb can be modeled as a sphere with a diameter of 7.5 cm. Determine the heat transfer from the bulb by the mechanism of forced convection.
Answer Preview: Sphere D 0075 m T 25CT s 145C v 155 1x10 5 1837x10 …

, Chapter: 10 -Problem: 9 >> At what point on the surface of the circular cylinder in a potential flow does the pressure equal the free-stream pressure?
Answer Preview: P v 2 2 Constant …

, Chapter: 25 -Problem: 9 >> Consider the catalytic reaction process shown in the figure below. The control volume has two catalytic zones: a porous catalyst (catalyst I) that fills the control volume, and a nonporous catalyst surface (catalyst II) on the left side of the control volume (x = 0; y = 0 to H). Reactant A diffuses into the porous catalytic material (catalyst I) with effective diffusion coefficient DAe, and is con
Answer Preview: 4 species A1 B2 C3 D4 inert R 1 k 1 c 1 r 1s k s c 1s a Assume 1 Dilute process with respect to …

, Chapter: 19 -Problem: 27 >> Water, at 60°F, enters a 1-in.-ID tube that is used to cool a nuclear reactor. The water flow rate is 30 gal/min. Determine the total heat transfer and the exiting water temperature for a 15-ft-long tube if the tube surface temperature is a constant value of 300°F. Compare the answer obtained using the Reynolds and Colburn analogies.
Answer Preview: v 1225 fts Reynolds analogy Assume T L 240 o F T avg 150 o F T F 225 o F f 00036 St 000…

, Chapter: 8 -Problem: 6 >> A thin rod of diameter d is pulled at constant velocity through a pipe of diameter D. If the wire is at the center of the pipe, find the drag per unit length of wire. The fluid filling the space between the rod and the inner pipe wall has density ? and viscosity ?.
Answer Preview: This is same configuration as shown in Prob 85 In…

, Chapter: 30 -Problem: 26 >> A “rotating disk” shown in the figure (at right) is used to plate a thin film of copper onto a silicon wafer by an electroless plating process at 25 C. The disk is 8.0 cm in diameter and rotates at a speed of 2.0 rev/s. The plating bath liquid volume is 500 cm3. In the electroless plating process, copper metal is deposited on a surface without an applied electrical potential. Instead, copper is de
Answer Preview: (a) The convective mass-transfer coefficient (kL) for copper ion diffusion across the liquid boundary layer formed by the spinning disk can be calcula…

, Chapter: 24 -Problem: 15 >> A microchannel reactor is being developed for the reforming of methane gas (CH4) to CO2and H2gas using steam (H2O vapor) at high temperature. Prior to entering the reforming reactor, CH4(species A) and H2O vapor (species B) at a nonreactive temperature of 400°C are mixed within a microchannel gas preheater zone with an inner diameter of only 50 microns (0.0050 cm). The Peclet number, defined asmus
Answer Preview: A CH 4 B H 2 O T 673 K d pore 5 10 3 cm v 40 cms a Knudsen diffusion coefficie…

, Chapter: 21 -Problem: 5 >> Four immersion heaters in the shape of cylinders 15 cm long and 2 cm in diameter are immersed in a water bath at 1 atm total pressure. Each heater is rated at 500 W. If the heaters operate at rated capacity, estimate the temperature of the heater surface. What is the convective heat-transfer coefficient in this case?
Answer Preview: Using English units Assume nu…

, Chapter: 9 -Problem: 23 >> A wide moving belt passes through a container of a viscous liquid. The belt moves vertically upward with constant velocity vw, as illustrated in the figure. Because of viscous forces, the belt picks up a thin film of fluid having a thickness h. Use the appropriate form of the Navier–Stokes equations to derive an expression for the velocity of the fluid film as it is dragged up the belt. Assume t
Answer Preview: Begin with the ydirection equation in rectangular coordinate…

, Chapter: 22 -Problem: 14 >> Compressed air is used in a heat-pump system to heat water, which is subsequently used to warm a house. The house demand is 95,000 Btu/h. Air enters the exchanger at 200°F and leaves at 120°F, and water enters and leaves the exchanger at 90°F and 125°F, respectively. Choose from the following alternative units the one that is most compact:a. A counter flow surface with U = 30 Btu/h ft2 °F and a su
Answer Preview: Counter flow UAC min 165 Cross flow air mixed UAC min …

, Chapter: 9 -Problem: 22 >> Two immiscible fluids are flowing down between two flat, infinitely long flat parallel plates as shown in the figure below. The plate on the left is moving down with a velocity of vA, and the plate on the right is moving up with a velocity vB. The dotted line is the interface between the two fluids. The fluids maintain constant widths as they flow downward and L1and L2are not equal. The flow is in
Answer Preview: I will show two different solutions the second solution may be slightly easier The only difference i…

, Chapter: 20 -Problem: 54 >> Compressed natural gas is fed into a small underground pipeline having an inside diameter of 5.9 in. The gas enters at an initial temperature of 120°C and constant pressure of 132.3 psig. The metered volumetric flow rate at standard pressure of 14.7 psia and standard temperature of 25°C is 195.3 ft3/min. The ground temperature is constant at 15°C, as it serves as an ‘infinite sink” for heat transf
Answer Preview: T T o 120C P 10 atm D 59 in 150 cm v o v D 2 4 v o 0010 m 3 sec at T 50C P 10 at…

, Chapter: 8 -Problem: 12 >> A continuous belt passes upward through a chemical bath at velocity v0 and picks up a film of liquid of thickness h, density, ?, and viscosity ?. Gravity tends to make the liquid drain down, but the movement of the belt keeps the fluid from running off completely. Assume that the flow is a well developed laminar flow with zero pressure gradient, and that the atmosphere produces no shear at the out
Answer Preview: For an element in liquid film In …

, Chapter: 26 -Problem: 33 >> Develop a model equation, in final, integrated algebraic form, to determine the total transfer rate of ethylene WA, units mole A/time, product of flux and surface area) into the cylindrical catalyst pellet. The model equation should include terms for the diffusion coefficient (D Ae), the dimensions of the pellet (Ro, R1, L), and concentration of ethylene. If the required transfer rate of ethylene.
Answer Preview: The model equation for the ethylene transfer rate is given by: A = -D Ae (Ce/r) (r2 - R1^2) (/L) whe…

, Chapter: 23 -Problem: 6 >> A tungsten filament, radiating as a gray body, is heated to a temperature of 4000°R. At what wavelength is the emissive power maximum? What portion of the total emission lies within the visible-light range, 0.3 to 0.75 ?m?
Answer Preview: From Wiens displacement law m…

, Chapter: 19 -Problem: 28 >> Work Problem 19.27 for the case in which the flowing fluid is air at 15 fps. Data From Problem 19.27Water, at 60°F, enters a 1-in.-ID tube that is used to cool a nuclear reactor. The water flow rate is 30 gal/min. Determine the total heat transfer and the exiting water temperature for a 15-ft-long tube if the tube surface temperature is a constant value of 300°F. Compare the answer obtained using
Answer Preview: T 0 300 240e 720St q DL vC p T s T b St 471 vC p St …

, Chapter: 9 -Problem: 16 >> Using the Navier–Stokes equations as given in Appendix E, work Problems 8.17 and 8.18.
Answer Preview: Taking z as positive down with v r v z 0 v z f…

, Chapter: 24 -Problem: 13 >> A process is being developed to deposit a thin film of silicon electronic grade silicon (Si) onto the inner surface of a hollow glass optical fiber by thermal decomposition of silane (SiH4) to solid Si. Silane gas is diluted in inert He gas to a composition of 1.0 mole% SiH4 and fed into the hollow glass fiber, which has an inner diameter of 10.0 microns (10.0 mm). The CVD process is carried out a
Answer Preview: A SiH 4 B He y A 001 y B 099 d pore 10 10 4 cm T 900 K a …

, Chapter: 20 -Problem: 26 >> Solve Problem 20.29 if the medium flowing past the tube in forced convection is water at 60°F. Data From Problem 20.29An electric light bulb rated at 60 W has a surface temperature of 145°C when cooled by atmospheric air at 25°C. The air flows past the bulb with a velocity of 0.5 m/s. The bulb can be modeled as a sphere with a diameter of 7.5 cm. Determine the heat transfer from the bulb by the me
Answer Preview: Water a Flow parallel to tube T f 150 F …

, Chapter: 23 -Problem: 11 >> Determine the fraction of total energy emitted by a black body, which lies in the wavelength band between 0.8 and 5.0 mm for surface temperatures of 500, 2000, 3000, and 4500 K.
Answer Preview: 1 08 m 2 5 m F 1T 1T F 0 2T F …

, Chapter: 22 -Problem: 6 >> As part of a food-processing operation, a single-pass, counter current, shell-and-tube heat exchanger must be designed to warm up a stream of liquid glycerin. The heat exchanger must be constructed of 0.75-in, outer diameter. gage 12 (relatively thick-walled) stainless steel tubes (k = 43 W/m · K) with inner diameters of 0.532 inch (1.35 cm) and total length of 5 m. In the present process, liquid
Answer Preview: Input Parameters 1253 kgm 3 C p 2501 JkgK 015 kgmsec k 0295 …

, Chapter: 5 -Problem: 27 >> Sea water, ρ = 64 lbm/ft3, flows through the impeller of a centrifugal pump at the rate of 800 gal/min. Determine the torque exerted on the impeller by the fluid and the power required to drive the pump. Assume that the absolute velocity of the water entering the impeller is radial. The dimensions are as follows:ω = 1180 rpm               t2 = 0.6 in.r1 = 2 in.                        Î¸2 = 135or
Answer Preview: Steady in compressible flow Rotation is …

, Chapter: 26 -Problem: 23 >> The immobilized enzyme layer shown in the figure below is designed to convert substrate A to product B according to the simplified reaction A ? B with simplified rate equation RA = –kcA. In this process, the steady-state concentrations of substrate A in the bulk liquid and the interface between the enzyme layer and its inert support surface were measured, with cA? = 1.0 mmol/m3 at z = 0, and cAL =
Answer Preview: Calculation. Q: What are valid boundary conditions for this process? A: The valid bounda…

, Chapter: 24 -Problem: 27 >> In a chromatographic separation process, a biomolecule of 20 nm diameter is diffusing into a random porous particle with void fraction (e) of 0.70 filled with elution solvent. However, the reduced pore diameter (j) for the diffusion process is only 0.010, and hindered diffusion of the solute within the solvent-filled pore can be neglected. If the desired effective diffusion coefficient (D'Ae) of t
Answer Preview: A solute B solvent Find solvent viscosity to achieve a D Ae of 10 x 10 7 cm …

, Chapter: 20 -Problem: 50 >> Air is transported through a rectangular duct measuring 2 ft by 4 ft.The air enters at 120°F and flows with amass velocity of 6 lbm/s · ft2. If the duct walls are at a temperature of 80°F, how much heat is lost by the air per foot of duct length? What is the corresponding temperature decrease of the air per foot?
Answer Preview: For the short distance in…

, Chapter: 6 -Problem: 2 >> Sea water, p = 1025 kg/m3, flows through a pump at 0:21 m3/s. The pump inlet is 0.25 m in diameter. At the inlet the pressure is -0.15 m of mercury. The pump outlet, 0.152 m in diameter, is 1.8 m above the inlet. The outlet pressure is 175 kPa. If the inlet and exit temperature are equal, how much power does the pump add to the fluid?
Answer Preview: Steady Flow m v 102521 21525 kgs v 1 vA 1 4278 m…

, Chapter: 23 -Problem: 21 >> A circular duct 2 ft long with a diameter of 3 in. has a thermocouple in its center with a surface area of 0.3 in.2. The duct walls are at 200°F, and the thermocouple indicates 310°F. Assuming the convective heat-transfer coefficient between the thermocouple and gas in the duct to be 30 Btu/h ft2 °F, estimate the actual temperature of the gas. The emissivity of the duct walls may be taken as 0.8 a
Answer Preview: Assuming thermocouple at geometric center …

, Chapter: 21 -Problem: 9 >> A circular pan has its bottom surface maintained at 200°F and is situated in saturated steam at 212°F. Construct a plot of condensate depth in the pan vs. time up to 1 h for this situation. The sides of the pan may be considered nonconducting.
Answer Preview: at a given depth y f hours ft x10 2 inches 0 0 0 02 0586 0…

, Chapter: 5 -Problem: 34 >> You have been given a project where you must attach a particular reducing pipe fitting into a Freon-12 delivery system. Freon-12 is a potentially hazardous material so you must be certain that the reducing pipe fitting is attached properly and will withstand the force due to the reduction in pipe diameter. The direction of the flow and the inlet and outlet positions are labeled in the figure below
Answer Preview: F x P 2 A 2 cos v 2 2 A 2 cos F x v 2 2 A 2 cos P …

, Chapter: 6 -Problem: 31 >> Referring to the figure below, assume the flow to be frictionless in the siphon. Find the rate of discharge in cubic feet per second, and the pressure head at B if the pipe has a uniform diameter of 1 in. How long will it take for the water level to decrease by 3 ft? The tank diameter is 10 ft. Transcribed Image Text:
Answer Preview: Calculations. The rate of discharge is given by; Q= A*v where; Q…

, Chapter: 25 -Problem: 11 >> The design of €œartificial organs€ for growing transplant able human tissues require that the cell type of interest, for example pancreatic cells, be grown and sustained within a three-dimensional array where the cells closely pack together to form a continuous living tissue. Furthermore, engineered systems for maintaining the tissues within the three-dimensional array require that oxygen be deli
Answer Preview: a System Tissue in quad IV A dissolved O 2 B tissue Assume 1 Steady state O 2 transport …

, Chapter: 21 -Problem: 14 >> If eight tubes of the size designated in Problem 21.13 are oriented horizontally in a vertical bank, what heat-transfer rate will occur?
Answer Preview: Horizontal tube c…

, Chapter: 5 -Problem: 15 >> Consider the differential control volume shown below. By applying the conservation of mass and the momentum theorem, show that dP + pv dv + g dy = 0 Transcribed Image Text: ?2, ?2? V2, A2 ?s (1) ?? P1, P1 V1, A1
Answer Preview: Cons of Mass Technique is to let …

, Chapter: 24 -Problem: 18 >> Estimate the liquid diffusion coefficients of the following solutes that are transferred through dilute solutions:a. Methanol in water at 288 Kb. Water in methanol at 288 Kc. n-butanol in water at 288 Kd. Water in n-butanol at 288 KCompare these estimated values to the available experimental values reported in Appendix J.2.
Answer Preview: T 288 K Physical property information Interpolate and convert Pas to cP from Appendix I to find visc…

, Chapter: 22 -Problem: 3 >> Air at 203 kPa and 290 K flows in a long rectangular duct with dimensions 10 cm by 20 cm. A 2.5-m length of this duct is maintained at 395 K, and the average exit air temperature from this section is 300 K. Calculate the air flow rate and the total heat transfer.
Answer Preview: 224 continued T b avg 295 K T f 3…

, Chapter: 5 -Problem: 18 >> The pressure on the control volume illustrated below is constant. The x components of velocity are as illustrated. Determine the force exerted on the cylinder by the fluid. Assume in-compressible flow. Transcribed Image Text: Vx = Vo 6d lale vo Ux = Vo
Answer Preview: Flow is steady incompressib…

, Chapter: 23 -Problem: 39 >> A duct with square cross section measuring 20 cm by 20 cm has water vapor at 1 atmosphere and 600 K flowing through it. One wall of the duct is held at 420 K and has an emissivity of 0.8. The other three walls may be considered refractory surfaces. Determine the rate of radiant-energy transfer to the cold wall from the water vapor.
Answer Preview: q gas to reradiating walls q gas re…

, Chapter: 20 -Problem: 4 >> A 2-in. copper cylinder, 6 in. in length, at a uniform temperature of 200°F, is plunged vertically into a large tank of water at 50°F. a. How long will it take for the outside surface of the cylinder to reach 100°F? b. How long will it take for the center of the cylinder to reach 100°F? c. What is the surface temperature when the center temperature is 100°F? Heat transfer from ends of the cylinder
Answer Preview: For T f 100F Gr L 107x10 6 12 3 100 1337x10 9 Pr 451 Re 60…

, Chapter: 5 -Problem: 2 >> If, in the system for Problem 5-1, the total drag on the object is measured to be 800 N/m of length normal to the direction of flow, and frictional forces at the walls are neglected, find the pressure difference between inlet and outlet sections. Data From Problem 5.1A two-dimensional object is placed in a 4-ft-wide water tunnel as shown. The upstream velocity, v1 is uniform across the cross secti
Answer Preview: System shown in Pr…

, Chapter: 24 -Problem: 9 >> Tetrachlorosilane (SiCl4) gas is reacted with hydrogen gas (H2) to produce electronic-grade polycrystalline silicon at 800°C and 1.5 × 105 Pa according to the reaction equation:SiCl4(g) + 2H2(g) ? Si(s) + 4HCl(g).The reaction rate may experience diffusion limitations at the growing Si solid surface. To address this concern, the diffusion coefficient coefficients in this system must be estimated.a.
Answer Preview: T 1073 K a Estimate D AB for SiCl 4 in H 2 A SiCl 4 and B H 2 From Appen…

, Chapter: 20 -Problem: 56 >> Consider a continuous-flow device described below used to pasteurize liquid milk, whose properties approach those of water. Milk at 20°C enters a preheater tube at a volumetric flow rate of 6 L/min. The inner diameter of the tube is 1.5 cm. The tube winds through a steam chest, which heats the milk. The outer tube wall temperature is maintained at 115°C using pressurized steam. Since the thermal c
Answer Preview: Input Parameters Process To 20 o C T s 115 o C D 15 cm 0015 m …

, Chapter: 6 -Problem: 10 >> In Problem 6.26, compute the upward force on the device from water and air. Use the results of Problem 6.26 as well as any other data given in that problem that you may need. Explain why you cannot profitably use Bernoulli's equation here for a force calculation. Data From Problem 6.26Water flows steadily up the vertical pipe and is then deflected to flow outward with a uniform radial velocity. If
Answer Preview: CVis red dashed line in the figure P A 10 Psig Flow rate must …

, Chapter: 31 -Problem: 18 >> A countercurrent gas absorption tower packed with 1.5 in ceramic Intalox saddles is used to process 360 kgmole/h of an inlet gas stream containing 10 mole% sulfur dioxide (SO2) in nitrogen (N2) gas. The process is temperature is 32 C, and the total system pressure is 1.5 atm. Since SO2 is not very soluble in water itself, 2.0Msodium hydroxide was added to the scrubbing solution. The mass flow rate
Answer Preview: a What is the required tower diameter (D) if the process is to operate at 60% of the flooding veloci…

, Chapter: 23 -Problem: 13 >> A small circular hole is to be drilled in the surface of a large, hollow, spherical enclosure maintained at 2000 K. If 100 W of radiant energy exits through the hole, determine (a) the hole diameter, (b) the number of watts emitted in the visible range from 0.4 and 0.7 ?m, (c) the ultraviolet range between 0 and 0.4 mm, and (d) the  infrared range from 0.7 to 100 ?m.
Answer Preview: For surroundings at 0 K D 00118 m 1188 cm In visible range 0…

, Chapter: 20 -Problem: 42 >> When the valve on the water line in Problem 20.38 is opened wide, the water velocity is 35 fps. What is the heat loss per 5 ft of water line in this case if the water and pipe temperatures are the same as specified in Problem 20.38? Data From Problem 20.38A tube bank employs tubes that are 1.30 cm in outside diameter at ST = SL = 1.625 cm. There are eight rows of tubes, which are held at a surface
Answer Preview: Re 307000 turbulent T f 130F us…

, Chapter: 6 -Problem: 22 >> The solution to 5.22 is Show that Bernoulli's equation applied between sections 1 and 2 does not give this result. Derive all expressions for the change in total head across a hydraulic jump. Transcribed Image Text: 1/2 h? h2 2 ghi,
Answer Preview: From Prob 522 For Bernoulli Eqn to be v solid h …

, Chapter: 24 -Problem: 2 >> Starting with Fick’s rate equation for the diffusion of A through a binary mixture of components A and B, provea. NA + NB = cVb. nA + nB = ? vc. jA + jB = 0
Answer Preview: a Prove N A N B cV Thus N A N B cV b Prove n A n B V From par…

, Chapter: 21 -Problem: 2 >> Plot values of the heat-transfer coefficient for the case of pool boiling of water on horizontal metal surfaces at 1 atm total pressure and surface temperatures varying from 390 to 450 K. Consider the following metals:(a) Nickel;(b) Copper;(c) Platinum;(d) Brass.
Answer Preview: In English units C L 103 Pr 17 274 h fg 97…

, Chapter: 6 -Problem: 36 >> Repeat the previous problem without the assumption that the velocity in the heating section is negligible. The ratio of the flow area of the heating section to the chimney flow area is R. Data From Problem 6.35A fluid of density ρ1 enters a chamber where the fluid is heated so that the density decreases to ρ2 The fluid then escapes through a vertical chimney that has a height L. Neglecting frict
Answer Preview: From Prob 628 Cons of Mass 1 v 2 2 v 3 2 vR …

, Chapter: 24 -Problem: 3 >> The general form of the Stefan€“Maxwell equation for mass transfer of species i in an n-component ideal gas mixture along the z-direction for flux is given by Show that for a gas-phase binary mixture of species A and B, this relationship is equivalent to Fick€™s rate equation: Transcribed Image Text:
Answer Preview: Given i A j B a…

, Chapter: 20 -Problem: 13 >> A “swimming-pool” nuclear reactor, consisting of 30 rectangular plates measuring 1 ft in width and 3 ft in height, spaced 21/2 in. apart, is immersed in water at 80°F. If 200°F is the maximum allowable plate temperature, what is the maximum power level at which the reactor may operate?
Answer Preview: Assuming each plate is independent T plate 200F T …

, Chapter: 5 -Problem: 29 >> A water sprinkler consists of two 1/2-in. diameter jets at the ends of a rotating hollow rod as shown. If the water leaves at 20 fps, what torque would be necessary to hold the sprinkler in place? Transcribed Image Text: 30° 12 in.
Answer Preview: For CV sh…

, Chapter: 23 -Problem: 18 >> A 7.5-cm-diameter hole is drilled in a 10-cm-thick iron plate. If the plate temperature is 700 K and the surroundings are at 310 K, determine the energy loss through the hole. The hole sides may be considered to be black.
Answer Preview: F 3 surr 034 q 3 surr …

, Chapter: 20 -Problem: 39 >> Rework Problem 20.53 for a staggered arrangement. All other conditions remain the same. Data From Problem 20.53Air at atmospheric pressure and 10°C enters a rectangular duct that is 6 m long having dimensions of 7.5 and 15 cm in cross section. The surfaces are maintained at 70°C by solar irradiation. If the exiting air temperature is to be 30°C, what is the required flow rate of the air?
Answer Preview: Same conditions as Prob 2053 excep…

, Chapter: 2 -Problem: 24 >> A watertight bulkhead 22 ft high forms a temporary dam for some construction work. The top 12 ft behind the bulkhead consists of sea water with a density of 2 slugs/ft3, but the bottom 10 ft begin a mixture of mud and water can be considered a fluid of density 4 slugs/ft3. Calculate the total horizontal load per unit width and the location of the center of pressure measured from the bottom.
Answer Preview: P A P atm p w g12 24g P B P atm 24g 40g 64g Between 0 A P P …

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, Chapter: 23 -Problem: 14 >> A furnace that has black interior walls maintained at 1500 K contains a peephole with a diameter of 10 cm. The glass in the peephole has a transmissivity of 0.78 between 0 and 3.2 µm and 0.08 between 3.2 µm and ?. Determine the heat lost through the peephole.
Answer Preview: T 1500 K Peephole D 10 cm 078 for 0 32 m 008 …

, Chapter: 21 -Problem: 15 >> Determine the heat-transfer coefficient for a horizontal 5/8 -in:-OD tube with its surface maintained at 100°F surrounded by steam at 200°F.
Answer Preview: Single horizontal tube h …

, Chapter: 6 -Problem: 24 >> A 1968 Volkswagen sedan is driving over a 7300-ft-high mountain pass at a speed of v m/s into a headwind of W m/s. Compute the gage pressure in mPa at a point on the auto where the velocity relative to the auto is v - W m/s. The local air density is 0.984 kg/m3.
Answer Preview: Bernoulli Eqn between fr…

, Chapter: 27 -Problem: 9 >> A new type of porous material serves as food packaging film, as shown in the figure below. The film rests on a nonporous metal plate. The packaging film is 0.20 cm thick (2.0 mm). The food contains liquid water, which exerts a vapor pressure of 0.030 atm at 25 C. At 25 C, the effective diffusion coefficient of water vapor in the porous film is 1.3 x 10-4 cm2/s, and the molecular diffusion coeffici
Answer Preview: Calculations. The time it will take for the water vapor to ac…

, Chapter: 22 -Problem: 25 >> Determine the required heat-transfer surface area for a heat exchanger constructed from 10-cm OD tubes. A 95% ethanol solution (cp = 3.8l0kJ/kg · K), flowing at 6.93 kg/s is cooled from 340 to 312 K by 6.30 kg/s of water that is available at 283 K. The overall heat-transfer coefficient based on outside tube area is 568 W/m2 · K. Three different exchanger configurations are of interest:a. Counterfl
Answer Preview: T w 281 Counter flow T LM 29 o …

, Chapter: 22 -Problem: 11 >> A shell-and-tube heat exchanger is used to cool oil (CH = 2.2kJ/kg · K) from 110°C to 65°C. The heat exchanger has two shell passes and four tube passes. The coolant (Cc = 4.20 kJ/kg · K) enters the shell at 20°C and leaves the shell at 42°C. For an overall tube-side heat-transfer coefficient of 1200 W/m2 · K and an oil flow of 11 kg/s. determine a. The coolant mass flow rate b. The required surfa
Answer Preview: To find F Fig 2…

, Chapter: 9 -Problem: 4 >> Find Dv/Dt in polar coordinates by taking the derivative of the velocity. (v = vr (r, ?, t)er + v? (r, ?, t)e?. Remember that the unit vectors have derivatives.)
Answer Preview: In similar fashion Giving UverVeo du drd0 dt dr de d…

, Chapter: 6 -Problem: 9 >> A liquid flows from A to B in a horizontal pipe line shown at a rate of 3 ft3/s with a friction loss of 0.45 ft of flowing fluid. For a pressure head at B of 24 in., what will be the pressure head at A? Transcribed Image Text: PA 24 in. 6 in. B 12 in.
Answer Preview: V 3 ft 3 s Between …

, Chapter: 25 -Problem: 5 >> A liquid flows over a thin, flat sheet of a slightly soluble solid. Over the region in which diffusion is occurring, the liquid velocity may be assumed to be parallel to the plate and to be given by v = ay, where y is the vertical distance from the plate and a is a constant. Show that the equation governing differential equation mass transfer of solute A to the flowing liquid, under certain simpli
Answer Preview: General differential equation for mass transfer rectangular coordinates Assume 1 Ste…

, Chapter: 20 -Problem: 21 >> What thickness of insulation having a thermal conductivity as given in Problem 20.22 must be added to the steam pipe of Problem 20.40 in order that the outside temperature of the insulation not exceed 250°F?
Answer Preview: Equations to be solved are Trial and error T …

, Chapter: 9 -Problem: 2 >> In Cartesian coordinates, show thatmay be written (v €¢ ˆ‡). What is the physical meaning of the term (v €¢ ˆ‡)? Transcribed Image Text: ? ? ? + Vz ? ?? dy ??
Answer Preview: vvexvyey vz talez dz d…

, Chapter: 5 -Problem: 1 >> A two-dimensional object is placed in a 4-ft-wide water tunnel as shown. The upstream velocity, v1is uniform across the cross section. For the downstream velocity profile as shown, find the value of v2. Transcribed Image Text: 2 ft 4 ft U2 v1 = 20 fps
Answer Preview: Cons of Mass v 1 A …

, Chapter: 23 -Problem: 26 >> A room measuring 12 ft by 20 ft by 8 ft high has its floor and ceiling temperatures maintained at 85°F and 65°F, respectively. Assuming the walls to be re-radiating and all surfaces to have an emissivity of 0.8, determine the net-energy exchange between the floor and ceiling.
Answer Preview: Walls assumed to be at a …

, Chapter: 21 -Problem: 1 >> An electrically heated square plate measuring 200 cm on a side is immersed vertically in water at atmospheric pressure. As the electrical energy supplied to the plate is increased, its surface temperature rises above that of the adjacent saturated water. At low power levels the heat-transfer mechanism is natural convection, becoming a nucleate-boiling phenomenon at higher ?Ts. At what value of ?T
Answer Preview: Plate is assumed to be copper For H 2 O 323 K L 0565 ft Natural c…

, Chapter: 10 -Problem: 8 >> In Problem 10.7, explain how one could obtain ?v? /?? at the stagnation point, using only r and ?vr /?r. Data From Problem 10.7For the flow about a cylinder, find the velocity variation along the streamline leading to the stagnation point. What is the velocity derivative ?vr/?r at the stagnation point?
Answer Preview: From contin…

, Chapter: 5 -Problem: 5 >> a. Determine the magnitude of the x and y components of the force exerted on the fixed blade shown by a 3-ft3/s jet of water flowing at 25 fps.b. If the blade is moving to the right at 15 fps, find the magnitude and velocity of the water jet leaving the blade. Transcribed Image Text: + 25 fps 30°
Answer Preview: Part a Steady incompressible flow In xdirection F x vA…

, Chapter: 23 -Problem: 5 >> A radiation detector, oriented as shown in the sketch, is used to estimate heat loss through an opening in a furnace wall. The opening in this case is circular with a diameter of 2.5 cm. The detector has a surface area of 0.10 cm2and is located 1 m from the furnace opening. Determine the amount of radiant energy reaching the detector under two conditions:a. The detector has a clear view of the ope
Answer Preview: a b With window q A A cos A T 21500 3000 F …

, Chapter: 21 -Problem: 7 >> A horizontal circular cylinder 1 in. in diameter has its outside surface at a temperature of 1200°F . This tube is immersed in saturated water at a pressure of 40 psi. Estimate the heat flux due to film boiling that may be achieved with this configuration. At 40 psi, the temperature of saturated water is 267°F.
Answer Preview: h 062 OA kpyApg hfg 04CpAT Duv Ts …

, Chapter: 8 -Problem: 9 >> Determine the velocity profile for fluid flowing between two parallel plates separated by a distance 2h. The pressure drop is constant.
Answer Preview: Fully developed steady lamin…

, Chapter: 2 -Problem: 30 >> A large industrial waste collection tank contains butyl alcohol, benzene, and water at 80°F that have separated into three distinct phases as shown in the figure. The diameter of the circular tank is 10 feet and its total depth is 95 feet. The gauge at the top of the tank reads 2116 lbf/ft3. Please calculate (a) The pressure at the butyl alcohol/benzene interface, (b) Pressure at the benzene/wate
Answer Preview: a The pressure at the butyl alcoholbenze…

, Chapter: 24 -Problem: 5 >> Consider the following properties of the atmosphere of the planet Mars at a particular measurement point on the surface, as measured by the Mars Rover:Average surface pressure: 6.1 mbarAverage temperature: 210 KAtmospheric gas composition (by volume): carbon dioxide(CO2) 95.32%; nitrogen (N2) 2.7%; argon (Ar) 1.6%; oxygen (O2) 0.13%; carbon monoxide (CO) 0.08%.a. What is the partial pressure of CO
Answer Preview: P 61 10 3 bar T 210 K yc O2 09532 y N2 0027 y Ar 0016 y O2 000…

, Chapter: 21 -Problem: 6 >> Two thousand watts of electrical energy are to be dissipated through copper plates measuring 5 cm by 10 cm by 0.6 cm immersed in water at 390 K. How many plates would you recommend? Substantiate all of the design criteria used.
Answer Preview: 2000 W 6826 Btuhr Per Plate A 2005 01 00…

, Chapter: 7 -Problem: 8 >> At what temperature is the kinematic viscosity of glycerin the same as the kinematic viscosity of helium?
Answer Preview: Properties of Helium Glycerin from …

, Chapter: 6 -Problem: 35 >> A fluid of density ρ1enters a chamber where the fluid is heated so that the density decreases to ρ2The fluid then escapes through a vertical chimney that has a height L. Neglecting friction and treating the flow processes as in-compressible except for the heating, determine the velocity, v, in the stack. The fluid velocity entering the heating chamber may be neglected, and the chimney is immerse
Answer Preview: From 1 to 2 From 3 to 4 Note …

, Chapter: 24 -Problem: 26 >> A size-exclusion based molecular separation process is being developed to purify a mixture of proteins dissolved in aqueous solution at 20°C. The solution is dilute and approximates the properties of water, which has a viscosity of 1.0 cP at 20°C. One protein of interest (protein A) is spherical with a mean molecular diameter of 25 nm. It is desired to design a porous membrane that has a stearic p
Answer Preview: a D AB for protein A …

, Chapter: 19 -Problem: 31 >> Work Problem 19.27 for the case in which the flowing fluid is sodium entering the tube at 200°F. Data From Problem 19.27Water, at 60°F, enters a 1-in.-ID tube that is used to cool a nuclear reactor. The water flow rate is 30 gal/min. Determine the total heat transfer and the exiting water temperature for a 15-ft-long tube if the tube surface temperature is a constant value of 300°F.
Answer Preview: T L T 0 Te St4LD Pr 000118 F f 00044 St 00022 Reyn…

, Chapter: 9 -Problem: 15 >> Obtain the equations for one-dimensional inviscid, unsteady, compressible flow.
Answer Preview: Continuity d…

, Chapter: 6 -Problem: 13 >> An automobile is driving into a 45-mph headwind at 40 mph. If the barometer reads 29 in. Hg and the temperature is 40°F, what is the pressure at a point on the auto where the wind velocity is 120 fps with respect to the auto?
Answer Preview: Energy Eqn reduces to P 2 v …

, Chapter: 25 -Problem: 10 >> Consider the drug treatment system shown in the figure below. A hemispherical cluster of unhealthy cells is surrounded by a larger hemisphere of stagnant dead tissue (species B), which is turn surrounded by a flowing fluid. The bulk, wellmixed fluid contains a drug compound (species A) of constant but dilute bulk concentration cAo. Drug A is also soluble in the unhealthy tissue but does not prefer
Answer Preview: a Assume 1 Steady state constant source and sink for A 2 1D flux along r 3 Diffusion limite…

, Chapter: 20 -Problem: 22 >> A cooking oven has a top surface temperature of 45°C when exposed to still air. At this condition the inside oven temperature and room air temperature are 180°C and 20°C, respectively, and heat is transferred from the top surface at 40 W. To reduce the surface temperature, as required by safety regulations, room air is blown across the top with a velocity of 20 m/s. Conditions inside the oven may
Answer Preview: For natural convection case plane upward facing hot surface Nu L 014Re L 13 if 2x10 7 Re 1…

, Chapter: 7 -Problem: 5 >> Estimate the viscosity of nitrogen at 175 K using equation (7-10). Transcribed Image Text: 28 · 183 1.200 · 10- µ = 2.6693 · 10-6. Pa · s (3.681)²(1.175)
Answer Preview: Nitrogen 175 K 26693x10 …

, Chapter: 5 -Problem: 35 >> The horizontal Y-fitting (see figure on the next page) splits 80°F water into two equal parts. The first part goes through Exit 1 and the second part goes through Exit 2 (as shown in the figure). The volumetric flow rate at the entrance is 8 ft3/sec, and the gage pressures at the three positions are 25 lbf/in.2at the entrance, 1713 lbf/ft2at exit 1, and 3433 lbf/ft2at exit 2. The diameters at the
Answer Preview: First calculate the force in the xdirection F x P entry A entry P 1 A 1 cos 50 P 2 A 2 cos 45 v 2 …

, Chapter: 23 -Problem: 36 >> A heavily oxidized aluminum surface at 755 K is the source of energy in an enclosure, which radiantly heats the side walls of a circular cylinder surface as shown, to 395 K. The side wall is made of polished stainless steel. The top of the enclosure is made of fire clay brick and is adiabatic. For purposes of calculation, assume that all three surfaces have uniform temperatures and that they are d
Answer Preview: F 13 018 F 12 082 R 5 0388 m …

, Chapter: 20 -Problem: 2 >> Repeat Problem 20.1 if the stagnant liquid is a. Bismuth at 700°F b. Hydraulic fluid at 0°F Data From Problem 20.1A 750-W immersion heater in the form of a cylinder with 3/4-in. diameter and 6 in. in length is placed in 95°F stagnant water. Calculate the surface temperature of the heater if it is oriented with its axis a. Vertical b. Horizontal
Answer Preview: Bismuth T 700 F As in problem 201 qA 26100 Btuhr ft 2 Vertical same formula as ab…

, Chapter: 9 -Problem: 11 >> Derive equation (2-3) from equation (9-27). Transcribed Image Text: Dv = pg – VP Dt
Answer Preview: For o of coordin…

, Chapter: 6 -Problem: 8 >> Find the change in temperature between stations (1) and (2) in terms of the quantities A1, A3, v1, v3, cv, and θ. The internal energy is given by cvT . The fluid is water and T1= T3, P1= P3. Transcribed Image Text: Top view (3
Answer Preview: Steady Flow Energy Eqn Cons of Mass v 1 A 1 …

, Chapter: 23 -Problem: 3 >> An opaque gray surface with ? = 0.3 is irradiated with 1000 W/cm. For an effective convective heat-transfer coefficient of 12W/m2 · K applying, and air at 20°C adjacent to the plate, what will be the net heat flux to or from a 30°C surface?
Answer Preview: Lee Lin bout net …

, Chapter: 22 -Problem: 8 >> Water enters a counter flow, double-pipe heat exchanger at a rate of 150 lbm/min and is heated from 60°F to 140°F by an oil with a specific heat of 0.45 Btu/lbm °F. The oil enters at 240°F and leaves at 80°F. The overall heat-transfer coefficient is 150 Btu/h ft2 °F.a. What heat-transfer area is required? b. What area is required if all conditions remain the same except that a shell-and-tube heat
Answer Preview: a b Water in shell oil 2 passes A cant be …

, Chapter: 9 -Problem: 6 >> Using the Navier€“Stokes equations and the continuity equation, obtain an expression for the velocity profile between two flat, parallel plates. Continuity equation, Transcribed Image Text: ?v0 ?? ??? ??
Answer Preview: Incompressi…

, Chapter: 5 -Problem: 19 >> Water flows in a pipe at 3 m/s. A valve at the end of the pipe is suddenly closed. Determine the pressure rise in the pipe.
Answer Preview: Fluid is H 2 0 V sonic 1433 …

, Chapter: 23 -Problem: 40 >> A gas of mixture at 1000 K and a pressure of 5 atm is introduced into an evacuated spherical cavity with a diameter of 3 m. The cavity walls are black and initially at a temperature of 600 K. What initial rate of heat transfer will occur between the gas and spherical walls if the gas contains 15% CO2 with the remainder of the gas being non-radiating?
Answer Preview: q net A G T 4 G G T 4 w A 4r 2 3 …

, Chapter: 20 -Problem: 33 >> The Solar World manufacturing facility in Portland, Oregon, is the largest producer of silicon-based solar cells in the United States. The manufacturing process begins with the melt crystallization of electronic grade silicon into a cylindrical ingot of poly crystalline silicon. The newly formed silicon ingots must then be cooled before they can be sliced into thin silicon wafers. In the present c
Answer Preview: Input Parameters D 30 cm 03m L 30 in K si 30 WmK T s 860K T 300K v 050 msec a b Heat transfer ra…

, Chapter: 7 -Problem: 11 >> An automobile crankshaft is 3.175 cm in diameter. A bearing on the shaft is 3.183 cm in diameter and 2.8 cm long. The bearing is lubricated with SAE 30 oil at a temperature of 365 K. Assuming that the shaft is centrally located in the bearing, determine how much heat must be removed to maintain the bearing at constant temperature. The shaft is rotating at 1700 rpm, and the viscosity of the oil is
Answer Preview: D i 3175 cm D o 3…

, Chapter: 6 -Problem: 33 >> Assume that the level of water in the tank remains the same and that there is no friction loss in the pipe, entrance, or nozzle. Determine a. The volumetric discharge rate from the nozzle b. The pressure and velocity at points A, B, C, and D Transcribed Image Text: 20 ft 20 ft 2 in. Diameter 23 ft 4
Answer Preview: Between 1 top of tank 2 at the exit of the nozzle v 2 2 0 2 gy 2 y 1 0 v 2 232220 12 359 fs In 4 …

, Chapter: 31 -Problem: 17 >> A counter-current packed tower will be used to remove H2S vapor from a N2-rich gas stream. In the present process, the inlet gas stream entering the bottom of the tower contains 5.0 mole% H2S at a superficial molar flowrate of 10 kgmole/m2/h, and the processed gas stream exiting the top of the tower must contain no more than 1.0 mole% H2S. Pure solvent containing no H2S enters the top of the tower
Answer Preview: To answer this problem, we need to use the equilibrium distribution of H2S between the gas and liquid, as provided in the table. The superficial molar …

, Chapter: 23 -Problem: 20 >> A cryogenic fluid flows in a 20-mm-diameter tube with an outer surface temperature of 75 K and an emissivity of 0.2. A larger tube, having a diameter of 50 mm, is concentric with the smaller one. This larger tube is gray, with ? = 0.05 and its surface temperature is 300 K. The intervening space between the two tubes is evacuated. Determine the heat gain by the cryogenic fluid, in watts per meter o
Answer Preview: 1 is inner cylinder 2 is outer cylinder With ra…

, Chapter: 20 -Problem: 3 >> An immersion heater, rated at 1000 W, is in the form of a rectangular solid with dimensions 16 cm by 10 cm by 1 cm. Determine the surface temperature of the heater if it is oriented in 295 K water with a. The 16-cm dimension vertical b. The 10-cm dimension vertical
Answer Preview: 16 cm 0525 ft vertical height 203 continued T …

, Chapter: 9 -Problem: 20 >> Determine the velocity profile in a fluid situated between two coaxial rotating cylinders. Let the inner cylinder have radius R1, and angular velocity ?1; let the outer cylinder have radius R2 and angular velocity ?2.
Answer Preview: From Prob 919 steady fl…

, Chapter: 5 -Problem: 8 >> At the end of a water pipe of 3-in. diameter is a nozzle that discharges a jet having a diameter of 1 1/2 in into the open atmosphere. The pressure in the pipe is 60 psig (pounds per square inch gage), and the rate of discharge is 400 gal/min. What are the magnitude and direction of the force necessary to hold the nozzle to the pipe?
Answer Preview: Fluid is H 2 0 P 1 60 Psig P 2 147 Psi…

, Chapter: 25 -Problem: 6 >> A device has been proposed that will serve as a €œblood oxygenator€ for a heart€“lung bypass machine, as shown in the figure below. In this process, blood containing no dissolved oxygen (O2, species A) enters the top of the chamber and then falls vertically down as a liquid film of uniform thickness, along a surface designed to appropriately wet blood. Contacting the liquid surface is a 100% O2ga
Answer Preview: a General differential equation for O 2 transfer in liquid film in terms of the …

, Chapter: 20 -Problem: 23 >> A €œhot stage€ for a manufacturing process is shown in the accompanying figure, where a slab of stainless steel is mounted on top of an electrical resistance heater. The stainless steel slab is 20 cm wide, 60 cm long, and 2 cm thick. A load material, which is placed on top of the stainless steel hot plate, requires a power input of 600 W. The dimensions of the load material are 20 cm in width, 60
Answer Preview: Process Input Parameters W 20 cm 02 m L 60 cm 06 m k s 16 WmK k m 20 WmK Air flow V 3…

, Chapter: 10 -Problem: 4 >> In polar coordinates, the continuity equation for steady in-compressible flow becomes Derive equations (10-10), using this relation. Transcribed Image Text: 1 dve = 0 r ?0 : (rv,) + - r ?r 1 ? Ur ? V? r ?0 ?r
Answer Preview: Let rv r …

, Chapter: 2 -Problem: 28 >> The float in a toilet tank is a sphere of radius R and is made of a material with density p. An upward buoyant force F is required to shut the ballcock valve. The density of water is designated pw. Develop an expression for x, the fraction of the float submerged, in terms of R, p, F, g, and pw.
Answer Preview: Spherical Float Upwar…

, Chapter: 23 -Problem: 33 >> Two disks are oriented on parallel planes separated by a distance of 10 in., as shown in the accompanying figure. The disk to the right is 4 in. in diameter and is at a temperature of 500°F. The disk to the left has an inner ring cut out such that it is annular in shape with inner and outer diameters of 2.5 in. and 4 in., respectively. The disk surface temperature is 210°F. Find the heat exchange
Answer Preview: From Figs 2314 2315 F 2 3 1 F 123 004 F 31 004 For black …

, Chapter: 21 -Problem: 17 >> Given the conditions of Problem 21.16, what height of vertical wall will cause the film at the bottom of the tube to be turbulent?
Answer Preview: L 34 327 L 485 ft 4Arc P…

, Chapter: 7 -Problem: 6 >> Calculate the viscosity of oxygen at 350 K and compare with the value given in Appendix I.
Answer Preview: Oxygen 350 K Eqn 7…

, Chapter: 5 -Problem: 32 >> Water flows at 30 gal/min through the 0.75-in.-diameter double-pipe bend. The pressures are p1= 30 lbf/in.2and p2= 24 lbf/in.2. Compute the torque T at point B necessary to keep the pipe from rotating. Transcribed Image Text: B 1 50° 3 ft 2
Answer Preview: 1 B 50 3 ft 2 MSSc Txvz pv dA ex ey ez …

, Chapter: 25 -Problem: 14 >> Consider the diffusion of solute A into the single cylindrical pore shown in the figure below. The end of the pore at z = L is sealed. The pore space is initially filled with inert fluid B. As solute A diffuses into the quiescent fluid space inside the pore space, it adsorbs onto the inner walls of the pore. The €œadsorption isotherm€ of solute A onto the solid surface of the pore is described by
Answer Preview: a Suggest system A phenol B H 2 O A species 1 in analysis below …

, Chapter: 20 -Problem: 49 >> Air at 25 psia is to be heated from 60°F to 100°F in a smooth, 3/4-in.-ID tube whose surface is held at a constant temperature of 120°F. What is the length of the tube required for an air velocity of 25 fps? At 15 fps?
Answer Preview: a v 25 fts Use Colburn anal…

, Chapter: 10 -Problem: 6 >> Make an analytical model of a tornado using an irrotational vortex (with velocity inversely proportional to distance from the center) outside a central core (with velocity directly proportional to distance). Assume that the core diameter is 200 ft and the static pressure at the center of the core is 38 psf below ambient pressure. Find a. The maximum wind velocity b. The time it would take a tornad
Answer Preview: In the core Eulers Eqn Since velocity variation is li…

, Chapter: 6 -Problem: 15 >> The pump shown in the figure delivers water at 59°F at a rate of 550 gal/min. The inlet pipe has an inside diameter of 5.95 in. and it is 10 ft long. The inlet pipe is submerged 6 ft into the water and is vertical. Estimate the pressure inside the pipe at the pump inlet.
Answer Preview: V 550 gm 1225 …

, Chapter: 26 -Problem: 1 >> The chemical vapor deposition of silane vapor (SiH4) forms a thin film of solid silicon as described in example 1, Chapter 25. Consider that the simplified CVD unit shown in Figure 25.5 is operating at 900 K and with a very-low-pressure total system pressure of 70 Pa. The diffusion path length (δ) is 5.0 cm, and the silane feed gas diluted in H2gas to a composition of 20 mole% silane. The Lennard
Answer Preview: A SiH 4 vapor B H 2 gas a Estimate the rate of Si film formation y As 0 DetermineD AB Materi…

, Chapter: 20 -Problem: 20 >> Solve Problem 20.18 if 3 in. of insulation having a thermal conductivity of 0.060 Btu/h ft °F is applied to the outside of the pipe. Neglect radiation from the insulation. What will be the outside surface temperature of the insulation? Data From Problem 20.18If the steam line described in Problem 20.40 is bare and surrounded by still air at 70°F, what total heat transfer would be predicted from a
Answer Preview: Insulation on outside wnatural convection on …

, Chapter: 7 -Problem: 10 >> Repeat the preceding problem for air. Data From Problem 7.9According to the Hagen–Poiseuille laminar flow model, the volumetric flow rate is inversely proportional to the viscosity. What percentage change in volumetric flow rate occurs in a laminar flow as the water temperature changes from near freezing to 140°F?
Answer Preview: For Air 140 F 134x105 LB m s…

, Chapter: 6 -Problem: 6 >> During the test of a centrifugal pump, a Bourdon pressure gage just outside the casing of the 12-in.-diameter suction pipe reads -6 psig (i.e., vacuum). On the 10-in.-diameter discharge pipe, another gage reads 40 psig. The discharge pipe is 5 ft above the suction pipe. The discharge of water through the pump is measured to be 4 ft3/s . Compute the horsepower input of the test pump.
Answer Preview: V 4ft 3 s P 1 6 …

, Chapter: 23 -Problem: 4 >> A black solar collector, with a surface area of 60 m2, is placed on the roof of a house. Incident solar energy reaches the collector with a flux of 800 W/m2. The surroundings are considered black with an effective temperature of 30°C. The convective heat-transfer coefficient between the collector and the surrounding air, at 30°C, is 35 W/m · K. Neglecting any conductive loss from the collector, de
Answer Preview: Energy balance for collector q in 800A W q out …

, Chapter: 22 -Problem: 19 >> In a biofuels plant a shell-and-tube heat exchanger is used to cool a stream of 100% carbon dioxide off-gas from a beer column from 77°C to 27°C (350 to 300 K) at 1 atm total system pressure. The total molar flow rate of CO2 gas is 36 kgmol/h (806.4 m3/h at STP). Liquid water will be used as the coolant. Cooling water is available at 20°C (293 K). CO2 gas flows in the tube side, water in the shell
Answer Preview: Appendix I M W 3 R k w 386 WmK Schedule 40 1 pipe D i 1049 in 267 x 10 2 m D o 1315 i…

, Chapter: 7 -Problem: 9 >> According to the Hagen–Poiseuille laminar flow model, the volumetric flow rate is inversely proportional to the viscosity. What percentage change in volumetric flow rate occurs in a laminar flow as the water temperature changes from near freezing to 140°F?
Answer Preview: For H 2 0 V 1 120 F w 0391x10 …

, Chapter: 2 -Problem: 21 >> A rectangular block of concrete 3 ft × 3 ft × 6 in. has its 6- in. side half buried at the bottom of a lake 23 ft deep. What force is required to lift the block free of the bottom? What force is required to maintain the block in this position? (Concrete weights 150 1b/ft3.)
Answer Preview: a To lift block from bottom F wt of concrete wt of H 2 …

, Chapter: 23 -Problem: 29 >> A circular heater, measuring 20 cm in diameter, has its surface temperature maintained at 1000°C. The bottom of a tank, having the same diameter, is oriented parallel to the heater with a separation distance of 10 cm. The heater surface is gray (? = 0.6) and the tank surface is also gray (? = 0.7). Determine the radiant energy reaching the bottom of the tank if a. The surroundings are black at 27°
Answer Preview: Problem statement asks for radiant energy reachin…

, Chapter: 20 -Problem: 25 >> A 1-in., 16-BWG copper tube, 10ft long, has its outside surface maintained at 240°F. Air at 60°F and atmospheric pressure is forced past this tube with a velocity of 40 fps. Determine the heat flux from the tube to the air if the flow of air is a. Parallel to the tube b. Normal to the tube axis
Answer Preview: q hT 180 h a Flow parallel to tub…

, Chapter: 9 -Problem: 8 >> The atmospheric density may be approximated by the relation ? = ?0 exp(-y/?), where ? = 22,000 ft. Determine the rate at which the density changes with respect to body falling at v fps. If v = 20,000 fps at 100,000 ft, evaluate the rate of density change.
Answer Preview: At y 100000 ft …

, Chapter: 5 -Problem: 9 >> A water jet pump has an area Aj= 0.06 ft2and a jet velocity vj= 90 fps, which entrains a secondary stream of water having a velocity vs= 10 fps in a constant-area pipe of total area A = 0.6 ft2. At section 2, the water is thoroughly mixed. Assuming one dimensional flow and neglecting wall shear a. find the average velocity of mixed flow at section 2; b. find the pressure rise (P2P1), assuming the
Answer Preview: H 2 0 Flow is …

, Chapter: 25 -Problem: 13 >> Consider a single, porous, spherical, inert mineral particle. The pores inside the particle are filled with liquid water (species B). We are interested in analyzing the molecular diffusion of the contaminant benzene (species A) within the water filled pores of the particle. Benzene is very sparingly soluble in water, and does not adsorb onto the inter surfaces of the pores. The process is isotherm
Answer Preview: A C 6 H 6 B H 2 O liq T 298 K c A is constant a Assume 1 Unsteady state control …

, Chapter: 19 -Problem: 29 >> Water at 60°F enters a 1-in.-ID tube that is used to cool a nuclear reactor. The water flow rate is 30 gal/min. Determine the total heat transfer, the exiting water temperature, and the wall temperature at the exit of a 15-ft long tube if the tube wall condition is one of uniform heat flux of 500 Btu/hr ft2.
Answer Preview: q mC p T 1960 T w ex…

, Chapter: 7 -Problem: 13 >> Two ships are traveling parallel to each other and are connected by flexible hoses. Fluid is transferred from one ship to the other for processing and then returned. If the fluid is flowing at 100 kg/s, and at a given instant the first ship is making 4 m/s whereas the second ship is making 3.1 m/s, what is the net force on ship one when the above velocities exist?
Answer Preview: Ship 1 v 1 4 ms Ship 2 v 2 31 ms Choose control volum…

, Chapter: 5 -Problem: 7 >> Oil (sp. gr. = 0.8) flows smoothly through the circular reducing section shown at 3 ft3/s. If the entering and leaving velocity profiles are uniform, estimate the force that must be applied to the reducer to hold it in place.  Transcribed Image Text: P = 5 psig D = 2.5 in. P = 50 psig D = 12 in.
Answer Preview: Flow is Steady Incompressible m v 086243 ft …

, Chapter: 25 -Problem: 13 >> Consider the cylindrical porous pellet shown in the figure below. A gas mixture of species A and B continually flows over the top face of the pellet. The sides and bottom of the pellet are sealed, and so serve as an impermeable barrier. Within the porous layer, species A forms species B by A B, with first order rate equation RA k cA.a. List at least three relevant assumptions of the mass transfer
Answer Preview: a. List at least three relevant assumptions of the mass transfer process, including the likely direc…

, Chapter: 4 -Problem: 11 >> A shock wave moves down a pipe as shown below. The fluid properties change across the shock, but they are not functions of time. The velocity of the shock is vw. Write the continuity equation and obtain the relation between p2, p1, v2, and vw. The mass in the control volume at any time is M = p2Ax + p1Ay. Use a control volume that is moving to the right at velocity vw.
Answer Preview: For the C V shown Steady flo…

, Chapter: 24 -Problem: 11 >> Steam reforming of hydrocarbons is one way to make hydrogen gas (H2) for fuel cell applications. However, the H2-rich pr

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