Overview of Transonic to Hypersonic Stage Separation Tool Development for Multi-Stage-To-Orbit Concepts

Abstract

An overview of research efforts at NASA in support of the stage separation and ascent aerothermodynamics research program is presented. The objective of this work is to develop a synergistic suite of experimental, computational, and engineering tools and methods to apply to vehicle separation across the transonic to hypersonic speed regimes. Proximity testing of a generic bimese wing-body configuration is on-going in the transonic (Mach numbers 0.6, 1.05, and 1.1), supersonic (Mach numbers 2.3, 3.0, and 4.5) and hypersonic (Mach numbers 6 and 10) speed regimes in four wind tunnel facilities at the NASA Langley Research Center. An overset grid, Navier-Stokes flow solver has been enhanced and demonstrated on a matrix of proximity cases and on a dynamic separation simulation of the bimese configuration. Steady-state predictions with this solver were in excellent agreement with wind tunnel data at Mach 3 as were predictions via a Cartesian-grid Euler solver. Experimental and computational data have been used to evaluate multi-body enhancements to the widely-used Aerodynamic Preliminary Analysis System, an engineering methodology, and to develop a new software package, "SepSim," for the simulation and visualization of vehicle motions in a stage separation scenario. Web-based software will be used for archiving information generated from this research program into a database accessible to the user community. Thus, a framework has been established to study stage separation problems using coordinated experimental, computational, and engineering tools.

Dynamic Stability Analysis of Hypersonic Transport During Reentry

“…The overset surface mesh on the geometry of a NGHT configuration selected from [9] is shown in Fig. 4.…”

“…In this paper, flutter boundary computations are made for a typical next-generation hypersonic transport (NGHT) configuration proposed earlier by NASA [9]. The OVERFLOW code [10] for Reynoldsaveraged Navier-Stokes (RANS) equations is used to compute the aerodynamic parameters.…”

“…Grids and time steps are selected based on detailed sensitivity studies similar to that performed by the author in [11,12]. Validation of steady data is made with earlier computations [9]. In this paper, a stability analysis is performed using the unsteady aerodynamic data in the form of indicial responses [13,14].…”

Aeroheating Characteristics for a Two-Stage-To-Orbit Concept During Separation at Mach 6

“…The present work adds experimental aeroheating data at Mach 6 to the existing database of aerodynamic data presented in Ref. 1. This database of an orbiter and booster of comparable size in close proximity can be used as a computational fluid dynamics validation tool.…”

CFD Approaches for Simulation of Wing-Body Stage Separation

“…This work is part of a larger effort to develop experimental and computational tools in support of the design of stage separation options for these vehicles. 1 Current work on the development and validation of computational fluid dynamics (CFD) tools for the simulation of winged body stage separation is reported here. We concentrate on the prediction of aerodynamic forces of vehicles in close proximity, used for the computation of separation trajectories.…”