Numerical simulation of the flow field of a two-stage turbine

Through the use of a three-dimensional viscous flow calculation program a numerical simulation was performed of a two-stage turbine. The program adopts a Godunov scheme of third-order accuracy with a turbulent flow model being of a B-L algebraic one. During the calculation the effect of a change in specific heat has been taken into consideration. An analysis of the calculation results indicates that there lacks a proper reflection of the matching of gas flow angles. This comes about because the gas turbine was designed and calculated through the use of a stream surface S₂ and single row viscous flow with losses being taken account of. As a result, there emerged a relatively great positive incidence angle in the second stage stator, leading to an ineffective role of adopting a rear loading profile and a failure to achieve an decrease in secondary flow loss. In view of this it is necessary to conduct in the aerodynamic design a calculation of the matching of multi-stage viscous flows.