Consider pressurized water, engine oil (unused), and NaK
(a) Determine the mean velocity, the hydrodynamic entry length, and the thermal entry length 11r each of the fluids when the fluid temperature is 366 K and the flow rate is
(b) Determine the mass flow rate, the hydrodynamic entry length, and the thermal entry length for water and engine oil at 300 and 400 K and a mean velocity of
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Fundamentals of Heat and Mass Transfer
Additional Engineering Textbook Solutions
Machine Elements in Mechanical Design (6th Edition) (What's New in Trades & Technology)
Applied Fluid Mechanics (7th Edition)
INTERNATIONAL EDITION---Engineering Mechanics: Statics, 14th edition (SI unit)
Fundamentals Of Thermodynamics
Fox and McDonald's Introduction to Fluid Mechanics
Degarmo's Materials And Processes In Manufacturing
- 6.1 Determine the heat transfer coefficient at the stagnation point and the average value of the heat transfer coefficient for a single 5-cm-OD, 60-cm-long tube in cross-flow. The temperature of the tube surface is , the velocity of the fluid flowing perpendicular to the tube axis is 6 m/s, and the temperature of the fluid is . Consider the following fluids: (a) air, (b) hydrogen, and (c) water.arrow_forward6.3 Steam at 100 kPa and is flowing across a 5-cm- OD tube at a velocity of 6 m/s. Estimate the Nusselt number, the heat transfer coefficient, and the rate of heat transfer per meter length of pipe if the pipe is at .arrow_forwardMerrill et al. (1965) in a series of classic experiments studied the flow of blood in capillary tubes of various diameters. The blood had a hematocrit of 39.3 and the temperature was 20°C. They measured the pressure drop as a function of the flow rate for five tube diameters ranging from 288 to 850 μm. When they expressed the measured pressure drops in terms of the wall shear stress, and the volumetric flow rates in terms of the reduced average velocity, all of the data for the various tube sizes formed, within the experimental accuracy, a single line as predicted by the Rabinowitsch equation expressed in terms of reduced average velocity. From their results they provide the following values of the Casson parameters at 20°C: τy = 0.0289 dynes cm−2 and s = 0.229 (dynes s cm−2)1/2. Using these values for τy and s, show that the equation below for reduced average velocity provides an excellent fit to their data summarized in the following table. (Wall shear stress) τw , dynes cm-2…arrow_forward
- 5. Steam condensing on the outer surface of a thin-walled circular tube of 50 mm diameter and 6 m length maintains a uniform surface temperature of 100 C. Water flows through the tube at a rate of m= 0.25 kg/s, and its inlet and outlet temperatures are Tmi = 15 C and Tmo = 57C. What is the average convection coefficient associated with the water flow? Data: Pvater = 1000 kg/m³ ; c, = 4.2 kJ/kg-K.arrow_forwardDetermine the mean heat-transfer coefficient and the quantity of heat transferred in water flowing in a horizontal tube 3 mm in diameter (d) and 2 m long (l), if ω = 0.3 m/sec; tf = 60 deg C and tω = 20 deg C. Constants: @ tf = 60oC, λf = 0.567 kcal/m-hr-oC; νf = 0.478 x 10-6 m2/sec β = 5.11 x 10-4 1/oC and Prf = 2.98. @ tω = 20oC, Pr? = 7.02arrow_forwardTwelve liters per minute of hot water at 330 K flow through a 0.5 inch schedule 40 (0.622 in wall thickness) domestic hot water line. What is the heat transfer coefficient inside the pipe? The kinematic viscosity is 0.5 x 106. The Prandtl number is 3.2.arrow_forward
- A tube with 2 cm inner diameter and 1 m length has uniform wall temperature water at 300 k with fully developed Velocity enters the tube with a mean Velocity of 0.05 m/s. The mean water exit temperature is 350 k. (a) find the surface temperature by using a thermally developed flow correlation? (b) if the Boundary Condition was Constant heat flux what would be the required heat flux? (C) for part b calculated the heat transfer coefficient and wall temperature at the middle of the tube?arrow_forward1. Experimental analysis was carried out about turbulent convective heat transfer in trapezoidal cross-sectioned duct.Average Nusselt numbers and Reynolds numbers were determined for each experiment and the following data set have beenobtained from this investigation. Find an engineering correlation between the average Nusselt number and Reynolds numberin the form ofNu = aRebarrow_forwardHeat transfer problem Water flows through a thin-walled cylindrical tube of diameter 1 cm, maintained at a uniform temperature, ?s = 360 K. The inlet and outlet temperature of water was found to be ?i= 280 K and ?o = 355 K, respectively. (a) What is the log mean temperature difference in this case? (b) If the mass flow rate is 0.005 kg/s, what is the total rate of heat transfer from the tube to the water? (c) What is the Reynolds number corresponding to the given flow conditions? (d) Assuming fully developed flow in the entire tube, what should be the length of the tube to allow the abovementioned operating conditions ?arrow_forward
- Liquid ammonia is transported from a production plant to a processing center via a 0.6-m diameter pipeline at a mass flow rate of 0.15 kg/s. Surface temperature of the pipe is maintained 0°C by using a cooling jacket with ice-cold water. Ammonia enters the pipeline at -17°C and exits at -3°C. Assume the flow is both hydrodynamically and thermally fully developed in the pipe. What is the length of the pipe? 1857marrow_forwardChoose the right answer 1. The mean Nusselt number for fully developed laminar flow in a circular tube under a constant heat flux a. depends on Reynolds number b. depends on Prandtl number c. is constant 2. The Prandtl number for a flowing fluid greater than unity indicates that the hydrodynamic boundary layer thickness is a. less than the thermal boundary layer thickness b. equal to the thermal boundary layer thickness c. greater than the thermal boundary layer thickness 3. In natural convection heat transfer, the Nusselt number is a function of a. Re and Pr b. Re and Gr c. Gr and Pr 4. A fluid is flowing coefficient along the length a. decreases long a plate ng a uniform heat flux. The local transfer b. remain constant c. increases 5. For fully developed laminar flow and heat transfer in a heated long circular tube, if the flow velocity is doubled and the tube diameter is halved, the heat transfer coefficient will be b. half of the original value a. four times of the original value…arrow_forwardChoose the right answer 1. The mean Nusselt number for fully developed laminar flow in a circular tube under a constant heat flux a. depends on Reynolds number b. depends on Prandtl number c. is constant 2. The value of Prandtl number for air is about а. О.1 b. 0.3 с. 0.7 3. In natural convection heat transfer, the Nusselt number is a function of a. Re and Pr b. Re and Gr c. Grand Pr 4. A fluid is flowing along a plate having a high uniform wall temperature. The heat transfer along the length a. decreases b. remain constant c. increases 5. For fully developed laminar flow and heat transfer in a heated long circular tube, if the flow velocity is doubled and the tube diameter is halved, the heat transfer coefficient will be a. four times of the original value before b. half of the original value с. same as d. double of the original valuearrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning