Institute of Fluid-Flow Machinery
Polish Academy of Sciences

Abstract

This research was undertaken an a preliminary investigation into the possibility of feeding steam into a turbine by means of a flow-vectoring volute scroll, intended as a replacement for the conventional guide vane ring in the first (control) stage of the turbine. A volute-shaped inlet can serve to distribute flow evenly along the circumference of the blade ring. The volutes considered in this paper are also intended to generate correct angular momentum in the stream, so that correct rotor inlet angles can be obtained by means of the volute alone. A one-dimensional analytical model of compressible flow through a volute is proposed and evaluated. The empirical coefficients needed for its closure are derived, for a range of volute configurations, from 3-D numerical simulation.