Aerothermoelastic-Acoustics Simulation of Flight Vehicles

Abstract

This paper describes a novel computational-fluid-dynamics-based numerical solution procedure for effective simulation of aerothermoacoustics problems with application to aerospace vehicles. A finite element idealization is employed for both fluid and structure domains, which fully accounts for thermal effects. The accuracies of both the fluid and structure capabilities are verified with flight-and ground-test data. A time integration of the structural equations of motion , with the governing flow equations, is conducted for the computation of the unsteady aerodynamic forces, which uses a transpiration boundary condition at the surface nodal points in lieu of the updating of the fluid mesh. Two example problems are presented herein to that effect. The first one relates to a cantilever wing with a NACA 0012 airfoil. The solution results demonstrate the effect of temperature loading that causes a significant increase in acoustic response. A second example, the hypersonic X-43 vehicle, is also analyzed; and relevant results are presented. The common finite element-based aerothermoelastic-acoustics simulation process, its applicability to the efficient and routine solution of complex practical problems, the employment of the effective transpiration boundary condition in the computational fluid dynamics solution, and the development and public domain distribution of an associated code are unique features of this paper.

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

“…The relations between the downstream and upstream static pressure p d and p u , respectively, and static temperature T d and T u , respectively, are presented in Equations ( 5) and (6). As the air is considered to be a perfect gas, the expression ρ = p RT is used to calculate the downstream density, where R is the gas constant in JK −1 kg −1 :…”

“…A CFD-based steady state and an unsteady solution initiations approach were implemented by Gupta and Voelker [5] in order to analyse the aeroelasticity of X-43A. Gupta et al also presented an aerothermoelastic-acoustics simulation process of a cantilever wing with a NACA 002 airfoil and the X-43A aircraft in [6].…”

A Review of Riemann Solvers for Hypersonic Flows

“…In general, engineers are inclined to employ four different ways to predict the aerodynamic force and heating loads of the hypersonic airliners, including flight test [ 10 ], empirical estimation methods [ 11 ], wind tunnel experiments [ 12 , 13 ], and Computational Fluid Dynamics (CFD) method [ 14 – 17 ]. Among these technologies, the empirical estimation method can not be applied to complex flows.…”