Question 4. The local friction coefficient for a fully turbulent boundary layer over a flat plate...
22. Consider the momentum integral equation turbulent boundary layer on an isothermal flat plate. The boundary layer is tripped at x-0. Assume constant properties and velocity. An experiment conducted to measure u and τ showed that for a steady, and τ= 0.0228 ρu® a) Determine the local friction coefficient, Cf/2 b) Using Colburn analogy, obtain an expression for the local Nusselt number.
1. (15 points] A boundary layer formed on one side of a plate of length L produces a friction drag force D. Using the expressions for tw given for laminar and turbulent boundary layers, how much must the plate be shortened if the drag on the new plate is to be D/4? (a) When the boundary layer is laminar (b) When the boundary layer is turbulent from the beginning? Assume everything else remains the same. 1. (15 points] A boundary...
The velocity profile for a turbulent boundary layer over a flat plate is to be approximated by the expression и an"* +b7072 where n=y/8 U a) (10P) Evaluate the coefficients a and b b) (20P) Obtain an expression for 8/x c) (5P) Obtain an expression for shear stress coefficient Cf. d) (5P) Draw velocity profile precisely.
Consider laminar flow of an incompressible fluid past a flat plate. The boundary layer velocity profile is given as u = U sin () a. Determine the boundary layer thicknesses 8, 8, as a function of x. Express in terms of Reynolds number. b. Using momentum integral theory, determine the wall shear stress tw, as a func. of x. Express in terms of Reynolds number. C. Determine the friction drag coefficient, Cof-
As shown in Fig. 1, the local velocity profile on a flat plate boundary layer is uz(x, y)/V = an+bn', where 7 = y/8(x) is a non-dimensional vertical coordinate, 8(x) is the boundary-layer 00 thickness, x is the streamwise coordinate, y is the coordinate normal to the wall, and V is the freestream velocity. (a) Calculate the local skin friction drag using the following momentum integral formula (Hint: x and 8(x) are treated as constants in the integral) (15 points)...
Air at 25 °C and 1 atm is flowing over a long flat plate with a velocity of 8 m/s. (a) Determine the distance from the leading edge of the plate where the flow becomes turbulent. (b) What will be the boundary layer thickness at the end of the plate? (c) If the plate is a 2m by 2 m square, what will be the friction drag acting on the plate? Schematic Given ssumptions Find v=8m/s xcr ,FD ,δ@x=L L-2m...
8) Air flows over a flat plate at a velocity of 20 m/s and a temperature of 20C. The surface temperature of the plate is 134C, and the length of the plate in the direction of flow is 1.5 m. Properties of air may be taken as A-0.030 W/m-C, Pr-0.700, and a/p 2.092E-5 m/s (5% ) What is the location from the leading edge, X, where the flow becomes turbulent Re (20)15 a l Ve30s T20 T LaLS 523 m...
10.13. The shear stress, Tw, on a flat surface that is caused by a fluid of density p and vis- cosity u flowing over the surface at a velocity V is given by where Re,- V Re where r is the distance from the upstream end of the flat surface. (a) Use the given shear stress distribution, w(x), to determine the drag force on a flat plate of width W and length L in terms of W, L, V, p,...
Consider air flows with velocity of U?=U= 10 m/s over a semi-finite smooth flat plate with L=97 cm long. Calculate the followings by assuming ? = 1.568 x 10-5 m2/s and ?=1.177 kg/m3. Figure 1 : Boundary layer over a flat plate Consider air flows with velocity of U?=U=10 m/s over a semi-finite smooth flat plate with L=97 cm long. Calculate the followings by assuming ? = 1.568 x 10-5 m2/s and ?=1.177 kg/m3. b) Under some flow and boundary...
Use the integral method for boundary layer flow and convective heat transfer over a flat plate heated by maintaining a constant heat flux q"w, for the case of very low Prandtl number, Pr0. Assume that the free stream velocity of the fluid, U, and free stream temperature, T-do not vary with x. Using the integral form of energy equation, show that under these conditions: (a) the temperature profile, (T- T) is given by, 41 2 CT-T oa (b) the wall...