Modeling and analysis framework for early stage trade-off studies for scramjet-powered hypersonic vehicles

NASA's Hypersonic Project aims at development of tools and methods for designing the next generation of space access vehicles which are envisioned to be scramjet-powered hypersonic vehicles. Design of such vehicles is a very challenging problem. Dynamic models of these vehicles tend to be highly complex and multi-disciplinary due to strong interaction between aerodynamics, propulsion, structure, and controls. Historically, the vehicle design process never incorporated control-centric considerations in the early stages of vehicle design. The control considerations came after the aero, propulsion, and structural design. The design obtained by such practice is not optimal and can often tend to be inadequate from a stability and performance view point. As a result, developing "low-order" models with "sufficient fidelity" to capture mission-critical control-centric phenomena becomes vital in early stages of vehicle design. The current modeling methodologies lie at the two extreme ends of the spectrum in terms of level of fidelity in the models. Most of the archival papers use a simple wedge-shaped planar three degrees-of-freedom (3 DOF) configuration for developing early-stage engineering models for analysis. The design decisions based on these models tend to be far too unreliable. On the other hand, CFD- and FEM-based high order models and related analysis tends to be extremely time consuming and inefficient in early stages of the design. This paper describes the modeling and analysis toolsuite that is being developed to fill in this gap in the modeling capability. The paper describes the overall first-principle based modeling framework and associated modules. The utility of the.