Full-Field Sonic Boom Simulation in Real Atmosphere

Abstract

As the sonic boom prediction method, the usefulness of the full-field simulation, in which the whole flow field including both the zone around a supersonic body and that on the ground is analyzed as a single computational domain, is assessed in this paper. The three dimensional Euler analyses including the gravity term have been numerically conducted to take into account the variation of the atmospheric properties with the altitude. The solutionadaptive structured grids are constructed by advancing the computational domain sector by sector for the grid lines to be aligned with the shock wave surfaces. The computations are made to reproduce the D-SEND#1 flight test by Japan Aerospace Exploration Agency (JAXA). The computational results are validated by comparing with the results of the waveform parameter method and the flight test data taken from the D-SEND database provided by JAXA. The maximum pressure rises of the present full-field simulations agree well with those of the waveform parameter method and the flight test data. Consequently, the present full-field simulations seem promising to analyze the natures of the sonic boom propagation in the realistic atmosphere model. Nomenclature E, F, G = flux vector at x, y, z coordinate E t = total energy g = acceleration of gravity h = altitude L LBM = length of body of Low Boom Model L NWM = length of body of N-Wave Model p = pressure p ∞ = atmospheric pressure Q = vector of conservative variables r = radial coordinate R = gas constant s 1 -s 5 = component in corrective term S C = corrective term for gravity term S G = gravity term t = time T 0 = atmospheric temperature at ground T ∞ = atmospheric temperature u, v, w = velocity in x, y, z direction x = streamwise coordinate y = vertical coordinate z = horizontal coordinate β = atmospheric temperature lapse rate Δr = distance in r direction θ = rotational coordinate ρ = density ρ ∞ = atmospheric density 1 Graduate Student, Department of Advanced Energy, 5-1-5 Kashiwanoha, yamashita@daedalus.k.u-tokyo.ac.jp, Student Member AIAA. 2 Professor, Department of Advanced Energy, 5-1-5 Kashiwanoha, kjsuzuki@k.u-tokyo.ac.jp, Senior Member AIAA. Downloaded by MONASH UNIVERSITY on August 1, 2015 | http://arc.aiaa.org |

Sonic Boom Prediction and Mitigation using Three-Dimensional Earth Effects

“…N ASA [1][2][3][4][5] and industry [6][7][8][9][10][11][12] are moving at a fast pace to enhance simulation tools to bring a commercial supersonic concept to fruition. There have also been efforts [13][14][15][16] to bring awareness to the broader aerospace community on the aspects of sonic boom prediction, impact and community response.…”

Full-Field Simulation for Sonic Boom Cutoff Phenomena

“…Therefore, various effects such as nonlinearity, geometrical spreading, atmospheric stratification, and diffraction can be considered by modifying the governing equations. For the case without the focusing of rays, the usefulness of full-field simulation has been previously confirmed by a comparison of two results as follows 7,8) : The first was the result of the waveform parameter method, 9) which was a representative evaluation method for sonic boom. The second was the result of the D-SEND#1 flight test 10) conducted by the Japan Aerospace Exploration Agency (JAXA).…”

“…Moreover, the discretization error of the gravity term and the error caused by the nonphysical wave in the Riemann solver are avoided by evaluating the correction term and setting the threshold value. 7,8) The correction term is derived as described in section 3.5. The threshold value is set as fol- Trans.…”