Consider the velocity boundary layer profile for flow over a flat plate to be of the form
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Fundamentals of Heat and Mass Transfer
- The answer is handwritten and step by steparrow_forwardQ4-Q6: A device is used to cool hot copper spheres of diameter 5 mm from an average temperature of 200C to 50C by letting them fall in air at 25°C and latm. Use drag coefficient C, = 0.4 and Whitaker correlation in your calculations. Assume the spheres fall at their terminal velocities during the process. Q4 improve the accuracy? Iteration is not required. ) Determine the terminal velocity of a sphere. Is the use of C, = 0.4 appropriate? If not, how toarrow_forwardi need the answer quicklyarrow_forward
- 3barrow_forwardConsider the laminar boundary layer flow of an isothermal fluid ( U ∞ , T ∞ ) over a flat isothermal wall ( T 0 ). At a certain distance x from the leading edge, the local skin friction coefficient is C f , x = 0.0066. What is the value of the local Nusselt number at the same location if the Prandtl number is Pr = 7?arrow_forwardThis is a practice question, not graded assignment. Understand that to find the answer to below question, we need to solve Navier-Stokes and energy equation for this flow to derive the velocity profile and temperature profile. Please show step-by-step equations including step-by-step integration. Please also provide explanation. An incompressible fluid flows through a rectangular cross section duct, with width much larger than height of the cross section. The duct surface is heated at a uniform rate along its length. If the centreline of the flow is along the centre of the duct where y = 0, the distance from the centreline to the surface of the duct is b = 25 mm, and the thermal conductivity of the fluid is 0.6 W/mK, what is the local heat transfer coefficient in the developed region of the flow? Give your answer in W/m^2K to 1 decimal place.arrow_forward
- We are testing a flat plate of length L = 1.125 m and width W = 0.225 m in a stream of air flowing with a velocity of 20 m/s. In test case 1, the air is flowing parallel to L and in test case 2 air is flowing parallel to W. Find: What portion of the boundary layer flow is laminar in each case? What is the highest laminar boundary layer thickness in each case? Assuming the flow is entirely turbulent over the plate, calculate the drag force in both test cases Take air density as 1.2 kg/m3 and its viscosity as μ=18×10−6μ=18×10−6 N.s/m2.arrow_forwardConsider a commercial airliner flying at a speed of 540 mph (relative to the air) at analtitude of 30,000 feet. (c) With a mean molar mass of M = 28.9 g/mol, determine the Reynolds number andMach number in flight. Justify your choice of characteristic length by referencinga commercial aircraft currently in service.(d) Is this flow inviscid or viscous? Is this flow subsonic or supersonic? Qualitativelydescribe the differences between these flight regimes.arrow_forwardThe wing of the Fairchild Republic A-10A twin-jet close-support airplane is approximately rectangular with a wingspan (the length perpendicular to the flow direction) of 17.5 m and a chord (the length parallel to the flow direction) of 3 m. The airplane is flying at standard sea level with a velocity of 200 m/s. Assume the wing is approximated by a flat plate and incompressible flow. If the critical Reynolds number for transition is 106, calculate the skin friction drag for the wing. Use turbulent drag as 2830 N. (Round the final answer to the nearest whole number.)arrow_forward
- I want the detailed solution to understand a questionarrow_forwardPlease helparrow_forward2. Consider laminar flat plate flow with the following approximate velocity profile: U[1-exp(-5y/6)] which satisfies the conditions u=0 at y=0 and u=0.993U at y = 8 a) Does this expression satisfy boundary condition applicable to the laminar boundary layer velocity profile? Determine b) the boundary-layer thickness variation (8/x) c) the displacement thickness variation (6*/x) d) the momentum thickness variation (0/x) e) the drag coefficient f) the drag force (FD) on the surface of the plate g) the shear stress on both sides of the plate h) Now explain why your results in parts (b) through (c) are deplorably inaccurate compared to the exact Blasius solution.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning