Numerical Investigation of Twin-Nozzle Rocket Plume Phenomenology.

摘要

The Generalized Implicit Flow Solver (GIFS) computer program has been modified and applied for the analysis of three-dimensional reacting two-phase flow simulation problems. The intent of the original GWS development effort was to provide the Joint Army, Navy, NASA, Air Force (JANNAF) community with a standard computational methodology to simulate the complete flow field of propulsion systems including multiple nozzle/plume flow field phenomena and other three-dimensional effects. The Van Leer Flux Splitting option has been successfully implemented into the existing GIFS model and provides a more robust solution scheme, making application of the model more reasonable for engineering applications. This paper reports the significant results of several twin-nozzle/ plume simulations using the GWS code. Eight simulations of Titan II plume flow fields have been completed to assess the effects of three-dimensionality, turbulent viscosity, afterburning, near-field shock structure, finite-rate kinetic chemistry, internozzle geometric spacing, nozzle exit plane profile, and missile body on the subsequent plume exhaust flow field. The results of these calculations indicate that the viscous stress model, kinetic chemistry especially at lower altitudes, and nozzle exit profile are important parameters that should be considered in the analyses and the interpretation of the calculations. Three-dimensionality is also an important influence, which can substantially influence the interpretation of the results. If three-dimensional effects are oversimplified in the model, analyses of the spatial results can be misinterpreted and misapplied. In addition, the missile body effect and internozzle geometric spacing influence the expansion shock reflection location which can significantly affect the plume/plume impingement shock location, inviscid shock structure, and shear layer growth.