Three-Dimensional, Unsteady, Inviscid Flow in an Axial Turbine Stage

Abstract

This paper presents an advanced approach to compute the three-dimensional,rotational, adiabatic, inviscid flow of a perfect gas in a highly twisted transonic axial turbinestage. The time-dependent Euler equations, expressed in a Cartesian coordinate system, aresolved using a time marching method and a finite volume approach. The absolute flow iscomputed in the nozzle vanes passage, whereas the relative flow is computed in the rotorblades passage. The phase relation of nozzle and rotor flows and the related blade rowinteraction are accounted for in the time-space domain. The results show that the presentmethod of calculation makes a practical contribution to predict actual turbine flows througha turbine stage that have an arbitrary number of vanes and blades for each nozzle and rotor.It is clear that this flow has a three dimensional aspects, in spite of the high hub/tip ratiowhich has theoretically a two-dimensional flow aspects.