SUPERSONIC FLOWS OF DENSE GASES IN CASCADE CONFIGURATIONS

We examine the steady, inviscid, supersonic flow of Bethe-Zel'dovich-T hompson (BZT) fluids in two-dimensional cascade configurations. Bethe- Zel'dovich-Thompson fluids are single-phase gases having specific heat s so large that the fundamental derivative of gasdynamics, Gamma, is n egative over a finite range of pressures and temperatures. The equatio n of state is the well-known Martin-Hou equation, and the numerical sc heme is the explicit predictor-corrector method of MacCormack. Numeric al comparisons between BZT fluids and lighter fluids such as steam are presented. It was found that the natural dynamics of BZT fluids can r esult in significant reductions in the adverse pressure gradients asso ciated with the collision of compression waves with neighbouring turbi ne blades. A numerical example of an entirely isentropic supersonic ca scade flow is also presented.