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.

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.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.24P: Engine oil at 100C flows over and parallel to a flat surface at a velocity of 3 m/s. Calculate the...

See similar textbooks

Similar questions

Air at 1000C flows at an inlet velocity of 2 m/s between two parallel flat plates spaced 1 cm apart. Estimate the distance from the entrance to the point where the boundary layers meet.
Air flow at a constant speed (Us = 10 m/s) is forming a two-dimensional incompressible laminar boundary layer along a flat plate The velocity profile inside the boundary layer is given by: =2-² A wind tunnel designer plans to build a two dimensional test section for a low speed wind tunnel. The design specification requires that in the test section the free stream flow must be equal to the air velocity at the entrance of the test section. (Figure Q2). U 30 m/s h₁ = 2²-² x,-0.0 Top wall Bottom wall -300 mm X-300 mm Figure Q2 Assuming the same velocity profile as in equation 1, and by using the momentum integral equation determine how much the bottom and top walls should be displaced at point 2 (x₂ = 300 mm) in order to achieve the design requirement as was stated above. In not more than 30-40 words justify your solution. Equation 1:
An approximation for the boundary-layer shape in is the formula u(y) - U sin 0 sys d where U is the stream velocity far from the wall and d is the boundary layer thickness, as in Fig. If the fluid is helium at 20°C and 1 atm, and if U = 10.8 m/s and 8= 3 cm, use the formula to (a) estimate the wall shear stress Tw in Pa, and (b) find the position in the boundary layer where t is one-half of Tw. -- y = 6 u(y)
Air (p= 1.2 kg/m³, kinematic viscosity v =1.8 + 10-5 m²/s )flows along a flat plat 3 m long and 1.5 m width with a velocity of 30 km/hr. 1)Find the distance over which the boundary layer is laminar 2) determine the friction drag force and the shear stress at location where boundary layer is laminar.
A fluid with viscosity of u = 1.752 x 10-5kg/m. s and density of p = 1.2kg/m3 flows at U=1 m/s over a flat plate. The boundary layer displacement thickness %3D at the end of the plate is reported 0.01315 m. Assuming the flow is laminar, (a) Find the boundary layer thickness at the end of the plate. (b) Find the momentum thickness at that location. (c) Find the drag force of the plate.
A 20 °C water flows to 50cmx60cm flat plate with velocity of 3m/s . The flat plate surface temperature is maintained at 40 °C. The air flows parallel to the 50cm side of the plate. If the kinematic viscosity of water is 78x10-8 m2/s, at what length the flow become turbulent?
(b) In two-dimensional boundary layer, shear stress was changed linearly from the solid surface toward y-axis until it reaches the value of zero at y = 8. Based on Table 2 and setting given to you; (i) Derive the equation of displacement thickness and momentum thickness using Von Karman Approximation Method; and (ii) Determine the accuracy of this method in determining the value of displacement thickness and momentum thickness. Table 2: Equation of Velocity Profile Equation u/U = 3(y/8)/2 – (y/8)³/2 Setting 2
(b) In two dimensional boundary layer, shear stress was changed linearly from the solid surface toward y-axis until it reach the value of zero at y = 6. Based on Table 2 and setting given to you; () Derive the equation of displacement thickness and momentum thickness using Von Karman Approximation Method ; and (ii) Determine the accuracy of this method in determining the value of displacement thickness and momentum thickness. Table 2 : Equation of Velocity Profile Setting Equation wU = 3(y/8)/2 – (y/8j?/2
3. Use scale analysis to find an expression for S/L and Nu, for flow over a flat plate with both boundary layers of equal thickness (8=ST)
A 20degC water flows to 50cmx60cm flat plate with velocity of 3m/s . The flat plate surface temperature is maintained at 40deg C. The air flows parallel to the 50cm side of the plate. If the kinematic viscosity of water is 78x10-8 m2/s, at what length the flow become turbulent? Round your answer to 2 decimal places.
Engine oil at 100°C flows on the top surface of a 1-m-long flat plate maintained at 20°C. The oil’s freestream speed (u infinity) is 0.1 m/s. Find the engine oil properties from the table A.5 A. Evaluate the Reynolds number, local convection coefficient, heat flux and shear stress at the end of the plate (x = L). Is the air flow laminar or turbulent over the plate?B. Evaluate the average convection coefficient, average heat flux, average shear stress and drag force over the plate.
A flow of air at 37m/s and at 1.6m from the leading edge. The transition Reynolds number is 3 x 10^5. If the boundary layer is laminar at this point If the boundary layer is turbulent at this point What is the boundary layer thickness in metres? Assuming that the air density is 1.226 kg/m3 and dynamic viscosity is 1.79 x 10-5 kg/ms