Integrated Aeropropulsive Computational Fluid Dynamics Methodology for the Hyper-X Flight Experiment

Abstract

Computational uid dynamics tools have been used extensively in the analysis and development of the X-43A Hyper-X Research Vehicle. A signi cant element of this analysis is the prediction of integrated vehicle aeropropulsive performance, which includes an integration of aerodynamic and propulsion ow elds. The development of the Mach 7 X-43A required a pre ight assessment of longitudinal and lateral-directional aeropropulsive characteristics near the target ight-test condition. The development of this pre ight database was accomplished through extensive aerodynamic wind-tunnel testing and a combination of three-dimensional inviscid airframe calculations and cowlto-tail scramjet cycle analyses to generate longitudinal performance increments between mission sequences. These increments were measured directly and validated through tests of the Hyper-X ight engine and vehicle owpath simulator in the NASA Langley Research Center 8-Foot High Temperature Tunnel. Predictions were re ned with tip-to-tail Navier-Stokes calculations, which also provided information on scramjet exhaust plume expansion in the aftbody region. A qualitative assessment of lateral-directional stability characteristics was made through a series of tip-to-tail inviscid calculations, including a simulation of the powered scramjet ight-test condition. Additional comparisons with wind-tunnel force and moment data as well as surface pressure measurements from the Hyper-X ight engine and vehicle owpath simulator model and wind-tunnel testing were made to assess solution accuracy. Nomenclature C A = axial force coef cient C l¯= rolling moment derivative, /deg C M = pitching moment coef cient C N = normal force coef cient C n¯= yawing moment derivative, /deg C p = pressure coef cient C y¯= side force derivative, /deg X; Y; Z = spatial coordinates, m ® = angle of attack, deg

Hyper-X Research Vehicle Experimental Aerodynamics Test Program Overview

“…The con guration developmentis backed by more than 5800 wind-tunnel runs. To assess the launch vehicle aerodynamic characteristics from B-52 dispense to stage separation, tests included 15 which has been experimentallyveri ed at several discrete ight-test conditions by a full-scale propulsion owpath test 16 conductedin the NASA Langley Research Center 8-Foot High Temperature Tunnel. Hypersonic cowl-closed ight stability and control (both immediately before and immediately after engine test) has been the emphasis of several entries into the 20-Inch Mach 6 and 31-Inch Mach 10 Tunnels, along with a few runs piggybackedon the stage separation test at AEDC VKF Tunnel B.…”

Guaranteed cost control with poles assignment for a flexible air-breathing hypersonic vehicle

“…The coupling between the propulsion system and the aerodynamic vehicles caused by the engine-airframe integration is hard to predict due to lack of flight and ground test facilities (Chavez and Schmidt 1999). Moreover, inconsistent with the assumptions in common flight conditions, the AHV structure will cause the vibrational modes to significantly affect aerodynamic forces and moments as well as controllability in the hypersonic environment (Bilimoria and Schmidt 1995;Cockrell et al 2001;Bolender and Doman 2007).…”

Elevator Sizing, Placement, and Control-Relevant Tradeoffs for Hypersonic Vehicles

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