Water at a flow rate of
(a) What is the required tube length if the coolant is air and its velocity is
(b) What is the tube length if the coolant is water and
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Fundamentals of Heat and Mass Transfer
Additional Engineering Textbook Solutions
Thinking Like an Engineer: An Active Learning Approach (3rd Edition)
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
Engineering Mechanics: Dynamics (14th Edition)
Introduction to Heat Transfer
Thinking Like an Engineer: An Active Learning Approach (4th Edition)
- 2- To solve these problems, refer to notes on Blackboard about convection inside pipes. Also, assume that the inside wall temperature of the cylinder is 100 °C Steam condensing circular tube of diameter D=50 mm and length L= 6 m maintains a uniform outer surface temperature of 100 °C Water flows through the tube at a rate m = 0.25 kg/s, and its inlet bulk temperature is To 15 °C. Determine: on the outer surface of a thin-walled a If the flow is laminar or turbulent b) The exit bulk temperature c) T (C) h (W/m2.K) d) Rate of heat transfer from steam to water e) A plot of T vs x, where x is the distance in axial direction along the pipe = 57 °C. Only State any assumptions made, and use L, guess one iteration is needed.arrow_forwardWater (cp = 4197 J / kgC, k = 0.67W / mC, Pr = 2.2, dynamic viscosity = 352 * 10 ^ -6 Ns / m ^ 2) with a flow rate of 0.01 kg / s and an inner diameter of 0.1 m at 20C temperature It is requested to be heated to 80C. If the pipe inner wall is kept constant at 120C, what is the average logarithmic temperature difference with fully developed flow acceptance? a. 65.48 C b. 43.3 C. c. 316.3 K D. 723.4 K e. 2300 K.arrow_forwardA 10 m long thin-walled stainless steel tube of diameter 15 mm is used to sterilize pharmaceutical products by heating it from 25 °C to 85 °C. A uniform heat flux is maintained on the outer surface of the tube by an electric resistance heater wrapped around it. If the flow rate of the liquid is 0.15 m/s, find the required heat flux. Is the flow in the tube laminar or turbulent? Assuming the fluid exits the tube with a fully developed velocity and temperature profile, determine the tube surface temperature at the exit. Explain the reasoning for assuming that the flow is fully developed.arrow_forward
- Water at 27°C flows with a mean velocity of 1 m/s through a 1 km-long pipe of 0.25 m inside diameter. Answer the following: a. Is the flow hydrodynamically fully developed? Support your answer with calculations. b. Is the flow thermally fully developed? Support your answer with calculations. c. What is the pressure drop over the pipe length, if the pipe surface is smooth? (Ans: 0.289 Bar) d. What is the pump power requirement, if the pipe surface is smooth? (Ans: 1.42 kW)arrow_forward6. Fluid in a round tube of radius R has a temperature profile of T = To(1+ :) and a velocity profile of u = uo(1 – ). (a) Calculate the mixed mean temperature. (b) Calculate the temperature you would get if you stopped the flow, dumped all the fluid in the tube into a cup, and mixed it until the temperature was uniform. (c) Explain why your answers to (a) and (b) are not the same.arrow_forwardQUESTION 9 A liquid cooled heat sink for a smartphone is sketched in Figure Q9. It uses water of density p = 997 kg m-3 and kinematic viscosity v = 1.19 x 10-6 m²-s-1 that runs in the x₁ direction through each of the five tubes of constant diameter D₁ = 5 mm and length Lx1 = 20 mm. It is supplied by a U = 0.017 m-s-1 uniform water inflow. Use Blasius' skin friction coefficient Cf = 0.664 / Rex1 0.5 to calculate the total skin friction drag force imparted by the flow on the heat sink walls. Calculate your answer in microNewtons, to one decimal place and enter the numerical value only. 1 microNewton = 10-6 Newtons. Partial credit is awarded for a reasonable approximation to the correct numerical answer. Lx₂ X2 Lx1 X1 Ő ve Heat Flux (9) (a) Figure Q9: Schematic of a liquid cooled heat sink LX3 4arrow_forward
- Water flows at a rate of 0.1 kg/s in a tube with a diameter of 250 mm. The tube is heated uniformly at a rate of 135 kW/m2. Find the wall temperature at a location where Tsat = 180 C and x = 25%. [Ans.: Ts = 188 C]arrow_forwardAir at 300 kPa and an average of 450 K is being heated as it flows through a rectangular conduit of 10 x 15 cm? at a velocity of 15 m/s. The heating medium is 500 K steam outside of the tube. Assume resistance of the conduit is small. Calculate the heat transfer for an L/d>60 and the heat transfer flux q/A.arrow_forwardQ2. Water is heated while following through a 1.5cmx 3.5cm rectangular cross section tube at a velocity of 1.2 m/s. The entering temperature of the water is 40°C and the tube wall is maintained at 85 C. Determine the length of the tube required to raise the temperature of water to 70 C. If the pressure loss in the tube is registered to be 10KPa. find the required pumping power. The properties of water are: p=985.5 kg/m², C- 4.18kJ/Kg. v-0.517x10 m/s, k-0.654 W/mK and Pr-3.26. Nu =0.023Re** Prarrow_forward
- A thick-walled cylinder tubing of hard rubber having an inside radius of 20mm is being used as temporary cooling coil in a bath. Ice water is flowing rapidly through inside tube and the inside wall temperature is 274.9K. The outside surface temperature is 297.1K. A total of 14.65W must be removed from the bath by cooling coil. How many m of tubing are required?arrow_forwardA shell-and-tube heat exchanger is used to cool compressed liquid methanol from 176 °F to 104 °F. The methanol flows on the shell side of the exchanger. The coolant is water that rises in temperature from 50 °F to 86 °F and flows within the tubes at a rate of 68.9 kg s1. Finding the appropriate thermophysical data and applying the proper equations, you are required to do the following: (a) Calculate i) methanol mass flow rate in the exchanger, ii) methanol volumetric flowrate at the inlet of the exchanger. (b) i) For the counter-current flow of the fluids calculate the log temperature difference, ii) explain the purpose of calculating this difference, iii) explain, quantitatively, why is the counter-current flow in heat exchangers preferred to co-current flow. meanarrow_forwardA liquid while flowing through a thin-walled cylindrical copper pipe (D=10 cm, L=1 m) with a mass flow rate of 0.001 kg/s is heated from Ti= 33 °C to Te= 98 °C by supplying constant surface heat flux to the pipe surface (all the heat is transferred to the fluid). Considering fully developed laminar flow in the pipe, what is the surface temperature of the pipe at the exit in Celsius? (For the fluid use, Cp 1800 J/kg.K, k= 0.2 W/m.K) = constant 117111 q's m = 0.001 kg/s 111 L=1m D= 10 cmarrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY