Aerodynamic Study of the NASA’s X-43A Hypersonic Aircraft

Àlex Navó,Josep M Bergada

doi:10.3390/app10228211

Abstract

A 2D aerodynamic study of the NASA’s X-43A hypersonic aircraft is developed using two different approaches. The first one is analytical and based on the resolution of the oblique shock wave and Prandtl–Meyer expansion wave theories supported by an in-house program and considering a simplified aircraft’s design. The second approach involves the use of a Computational Fluid Dynamics (CFD) package, OpenFOAM and the real shape of the aircraft. The aerodynamic characteristics defined as the lift and drag coefficients, the aerodynamic efficiency and the pitching moment coefficient are calculated for different angles of attack. Evaluations are made for an incident Mach number of 7 and an altitude of 30 km. For both methodologies, the required angles of attack to achieve a Vertical Force Balance (VFB) and a completely zero pitching moment conditions are considered. In addition, an analysis to optimise the nose configuration of the aircraft is performed. The mass flow rate throughout the scramjet as a function of the angle of attack is also presented in the CFD model in addition to the pressure, density, temperature and Mach fields. Before presenting the corresponding results, a comparison between the aerodynamic coefficients in terms of the angle of attack of both models is carried out in order to properly validate the CFD model. The paper clarifies the requirements needed to make sure that both oblique shock waves originating from the leading edge meet just at the scramjet inlet clarifying the advantages of fulfilling such condition.

Highlights

NASA X-43A, known as a Hyper-X Research Vehicle (HXRV), was one of the different NASA’s uncrewed hypersonic aircraft designed with the innovative scramjet propulsion technology to fly at high speeds and high altitudes
Hyper-X was the experimental hypersonic flight research program of X-43A managed by NASA whose main objective was to demonstrate, validate and implement the technology, the experimental techniques and the computational methods and tools for design and performance predictions of a hypersonic aircraft with an airframe-integrated, scramjet propulsion system
Since the aerospace industry that is focused on hypersonic flight vehicles such as X-43A is very demanding in terms of high performance, a large amount of profound studies based on experimental techniques or computational algorithms on each technological part of those aircraft are extremely necessary

Summary

Introduction

NASA X-43A, known as a Hyper-X Research Vehicle (HXRV), was one of the different NASA’s uncrewed hypersonic aircraft designed with the innovative scramjet propulsion technology to fly at high speeds and high altitudes. Hyper-X was the experimental hypersonic flight research program of X-43A managed by NASA whose main objective was to demonstrate, validate and implement the technology, the experimental techniques and the computational methods and tools for design and performance predictions of a hypersonic aircraft with an airframe-integrated, scramjet propulsion system. Since the aerospace industry that is focused on hypersonic flight vehicles such as X-43A is very demanding in terms of high performance, a large amount of profound studies based on experimental techniques or computational algorithms on each technological part of those aircraft are extremely necessary.

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Results

Conclusion