USING A FULL-POTENTIAL SOLVER FOR PROPULSION SYSTEM EXHAUST SIMULATION

The need for accurate simulations of engine installations on modern co mmercial transport aircraft has led to consideration of several formul ations capable of modeling engine exhausts. Since such exhausts often interact with wings, struts, and nacelles, a complex geometry computat ional fluid dynamics (CFD) capability is desirable. Engine exhausts of ten contain nonlinear effects such as weak shock waves. There are very few CFD codes that can model these effects for complex geometries in a timely way. However, a full potential formulation has been implement ed in the general geometry code TRANAIR. This model incorporates certa in assumptions, the main one being that the flowfield can be divided i nto a finite number of regions in each of which the total pressure and total temperature are constant. The purposes of this article are to s tate the theoretical assumptions made by the full potential and Euler models and to validate the methods on an axisymmetric test case. In th e situations considered (typical of modern turbofan engines) the full potential and Euler results agree very well.