Abstract:

A complex method is used in optimization of angular momentum distribution for radial inward flow turbines. Firstly, select a number of points ｛X j｝=｛(λ 1 λ 2 … λ n) T j｝ which satisfy all restriction conditions and are taken as the apexes of an initial complex. Then, at every kind of angular momentum distribution ( λ 1 λ 2 … λ n) T j do computation of the main flow field for the S 2 flow surface and for the S 1 flow surface of the turbine impeller, do computation of momentum thickness of the blade’s two dimensional turbulent boundary layer, and do correction of the three dimensional effect on the thickness. By that, estimate the impeller efficiency η . Finally, it can make object function f (X)=1-η have a minimum value. This method can also suit centrifugal impellers. In this paper, an application example is given for a radial inward flow turbine. This optimization of angular momentum distribution can make the turbine have isentropic efficiency 86% and have better off design characteristics.

Key words: radial turbines, angular momentum, distributions, optimization