Introduction into Boundary Layer Theory

摘要: In Chapter 19 we have shown that using the computational fluid dynamics (CFD), flow details in and around complex geometries can be predicted with an acceptable degree of accuracy. The field calculation includes very close to wall, where viscosity plays a significant role. absence random fluctuations (laminar) calculated high For predicting turbulent flows, however, turbulence models were required implemented into Navier-Stokes equations account for fluctuations. One more important tasks turbomachinery mechanics is predict drag forces acting on surfaces such as turbine compressor blade surfaces, endwalls, inlet nozzles exit diffusers. As seen 6, are produced by which causes shear stress surface. question arises how far from surface dominates field. Prandtl [1] was first answer this question. Combining his physical intuition experiments, he developed concept boundary layer theory. This theory its differential or integral forms applied determine profile loss. It delivers accurate results long not separated.