Question

4. (a) What is meant by an "adverse pressure gradient what makes t adverse? [2] (b) Why will a lamınar boundary layer separate more easily than a turbulent one? (c) A simple approach for solving for the development of a boundary using the Momentum Integral Equation dx used is to assume a shape for the velocity profile. The following fom has sometimes been 3 where u, is the velocity at the edge of the boundary layer, y [6] [4] (i) what boundary conditions are satisfied by Equation (1)? (ii) It can be shown that relationship between the momentum thickness θ iu tu li 39 280 and boundary layer thickness & based on Equation (Derive an expression for the skin fiction coefficient c, in terms of θ pu (ii) Using the Momentum Integral Equation and the results from (ii) to predict the development of θ for a flat-plate boundary layer from the leading edge (: 0) to some arbitrary distance along the plate x Compare the predicted value of 0 with that from the exact solution due to Blasius, which gave [6] 8 0.664 where Re, - P [20]

Answer 1