Entropy Generation Analysis of a Flat Plate Boundary Layer with Various Solution Methods

Steady state boundary layer equations over a flat plate with a constant wall temperature canbe solved by an integral solution (with three profiles for velocity and temperature), a similaritysol ution (exact) and a blasi us series solution. the analysis of entropy generation for each solutionis carried out. the results show that the exact solution (similarity) is the one that minimizes therate of total entropy generation in the boundary layer. then, the blasius solution has the leastentropy generation of all. the bell-shaped profile (sinus profile) in the integral solution generatesless entropy than the piecewise linear profile, consequently. so, with this method, if the exactsolution for a specified problem were not available, one could evaluate the approximate solutionsand recognize the best one among them. by introducing a new non-dimensional number (ejnumber), which is the ratio of thermal entropy to friction entropy generation, one can recognizewhich of them is dominant in the boundary layer. also, it is observed that variation of thetotal entropy generation is the same as the variation of boundary layer thickness, so, the nondimensionaltotal entropy generation for various solutions is constant.