The goal of this research is to produce a new, robust, parabolized Navier-Stokes (PNS) code which will significantly reduce computer time required to calculate flows about complex vehicles with embedded subsonic regions. One of the major drawbacks of "current day" PNS codes is that they cannot be used to compute inviscid subsonic/separated regions which occur near canopies, wing-body junctures, etc. The current practice is to use a full Navier-Stokes(N-S) code in these regions and use a PNS code for the remainder. Because of the difficulties associated with interfacing two different codes, many investigators have resorted to using a N-S code for the entire flowfield. This is in spite of the fact that a PNS code is at least one order of magnitude faster than a N-S code. In the proposed research, innovative techniques will be developed to detect and measure the extent of embedded subsonic regions. In these "elliptic" regions, the PNS equations will be solved "globally" in an iterative fashion to duplicate the results obtained with a N-S code. During Phase I, a 2-D version of the code will be developed using NASA's UPS code as a framework. During Phase II, a fully three- dimensional code will be produced.Commercial Applications:The new PNS code developed in this study will significantly reduce the computer time required to calculate flows about supersonic/hypersonic vehicles such as the proposed high-speed civil transport(HSCT). The code will accurately predict surface pressures, heat transfer rates, and aerodynamic coefficients for the entire vehicle. Designers throughout the aerospace industry will be able to utilize the efficiency of the new code to incorporate viscous effects in their trade-off studies of future flight vehicles.
