The importance of force terms modeling within the streamline curvature through-flow method

Abstract

Gas turbine engine performance simulation goes hand in hand with gas turbine engine development, as well as with operational improvement aspects of existing engines. The increasing availability of computational power at an affordable cost is the main drive behind the investment in the development of computer-based, gas turbine engine performance simulation techniques. The current paper refers to through-flow methods. The study is particularly focused on the force terms appearing in the inviscid set of flow equations as a means of balancing explicitly modeled effects. The influence of each force term on the solution stability and accuracy is addressed, as well as the way such terms can be optimally included in the equations causing the least possible numerical discrepancies. The flow simulation tool used for the current study was “SOCRATES,” a through-flow simulation code based on the streamline curvature method. A two-stage axial flow fan was the basis for this study, the findings though stand generally for turbomachinery flow simulation using the streamline curvature method. The main drive behind the current study was the fact that the increasing complexity of the radial equilibrium equation is reflected on the convergence behavior of the flow model and thus on the robustness and computational power consumption of the underlying simulation tool. The paper is structured in two main sections. The first one covers the theoretical background and the description of the simulation tool. The second section presents flow simulation results compared against experimental data. The paper is concluded by summarizing the main findings of this study.