Aerodynamic Analyses of Variable Geometry Asymmetric Supersonic Nozzles

The objective of the research is to develop a two dimensional supersonic nozzle with adaptable geometry that will allow a range of exit supersonic speeds ranging from Mach 1.29 to 4. The uniformity of the exiting air stream was the primary performance indicator. The asymmetric geometry is intended to be used in supersonic wind tunnels were uniform exit flow and a range of usable Mach numbers increases the utility of the tunnel. Numerical tools using the method of characteristics were developed using MATLAB to create an initial inviscid nozzle profile. Geometric constraints lead to the development of a two nozzle approach. It was found that an inviscid asymmetric nozzle geometry derived through the method of characteristics could be successfully adapted to create asymmetric nozzle profiles to include viscous effects. Numerical methods employing RANS solvers were required to adapt the asymmetric nozzle geometry. The uniformity of the exiting air stream was highly dependent on the downstream nozzle geometry. With effective geometry adaptation, the average variation of exiting nozzle velocity for a viscous flow was reduced to 1% and no less.