Numerical model of sonic boom in 3D kinematic turbulence

Coulouvrat, François; Luquet, David; Marchiano, Régis

doi:10.1063/1.4934474

Cited by 8 publications

(4 citation statements)

References 11 publications

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“…For near-field pressure prediction, recent lessons learned include the need to run viscous as opposed to inviscid simulations to extract more accurate pressure information, resolving plume effects [21], and inlet integration [22]. Atmospheric propagation also has seen enhancements in the form of lossy propagation [23], adjoint methods [3,24], non-empirical physics-based focus prediction [25], edge of the boom carpet diffraction [26], and atmospheric turbulence [27] effects. However, several other effects such as spherical or ellipsoid Earth effects, mean-flow wind effects [28,29], prediction in the shadow region [26], over-the-top secondary booms etc., have not been extensively researched, particularly for lossy propagation implementations, though formulations exist in literature.…”

Section: Introductionmentioning

confidence: 99%

Sonic Boom Prediction and Mitigation using Three-Dimensional Earth Effects

Rallabhandi

2018

2018 Applied Aerodynamics Conference

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Section: Introductionmentioning

confidence: 99%

Sonic Boom Prediction and Mitigation using Three-Dimensional Earth Effects

Rallabhandi

2018

2018 Applied Aerodynamics Conference

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“…A state-of-the-art code [26] was developed by UPMC for statistical prediction of sonic boom through turbulent atmosphere. Numerous validation tests have been successfully carried out to simulate the propagation of the sonic boom in a turbulent atmosphere [27] [28] including flow motion, sound speed and density heterogeneities, atmospheric absorption (thermo-viscosity and N2/O2 molecular relaxation) and rigid ground reflection (Figure 8) [24] [28]. Figure 7: Left: example of automatic mesh adapted to shock capturing -Right: ground footprint of sonic boom from ATLLAS II configuration at cruise Mach number 5 (colours indicate peak overpressure in Pa) [24].…”

Section: Ii3 Environmental Impact -Sonic Boom and High Altitude Emissionsmentioning

confidence: 99%

“…For ground track boom, standard deviation is relatively high and positively skewed, indicating that there is a significant probability of high intensity peak pressure. For lateral boom in the shadow zone, peak overpressure is enhanced due to sound scattering by turbulence [28].…”

Section: Low Turbulencementioning

confidence: 99%

Achievements obtained within ATLLAS-II on Aero-Thermal Loaded Material Investigations for High-Speed Vehicles

Steelant¹,

Dalenbring²,

Kuhn³

et al. 2017

21st AIAA International Space Planes and Hypersonics Technologies Conference

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The co-founded FP7 EC project ATLLAS-II had as objectives the identification and assessment of advanced lightweight and high-temperature resistant materials for high-speed vehicles up to Mach 6. The material requirements were defined through an in-depth feasibility study of a Mach 5-6 vehicle. The consortium could build upon a set of validated tools, material databases and valuable experience acquired during ATLLAS-I. Starting with a preliminary aero-thermal-structural high-speed vehicle design process, a multi-disciplinary optimization and experimental testing resulted into a detailed layout of a high-speed vehicle. Special attention was given to alleviate sonic boom and emissions at high altitudes. Throughout the design process, the aero-thermal loads defined the requirements for the proposed materials and cooling techniques needed for both the airframe and propulsion components. The former focused on sharp leading edges, intakes and skin materials each coping with different external aero-thermal loads. The latter were exposed to internal combustion driven loads. Both metallic (Titanium Matrix Composites and Ni-based Hollow Sphere Stackings) and non-metallic materials (Ceramic Matrix Composites and Ultra High Temperature Ceramics) were evaluated. Combined aero-thermal-structural experiments tested various materials at extreme conditions representative for high flight Mach numbers. Both static and cyclic tests at low and high temperatures were performed including the evaluation of their durability in terms of long duration exposure to the harsh flight conditions. The materials assigned to dedicated engine components were exposed to realistic combustion environments. These were combined with passive or active cooling technologies developed in ATLLAS-I.

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“…In contrast, relatively few studies have focused on vertical and slanted propagation. Some such studies mentioned here include applications to low-flying aircraft, 8 a sound source on a 150m tower, 9 sonic boom propagation, [10][11][12] and auralization of flying aircraft. 13 Ostashev and Wilson 14 provide an additional review of this subject.…”

Section: Introductionmentioning

confidence: 99%

Vertical and slanted sound propagation in the near-ground atmosphere : amplitude and phase fluctuations

Kamrath¹,

Ostashev²,

Wilson³

et al. 2021

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Sound propagation along vertical and slanted paths through the near-ground atmosphere impacts detection and localization of low-altitude sound sources, such as small unmanned aerial vehicles, from ground-based microphone arrays. This article experimentally investigates the amplitude and phase fluctuations of acoustic signals propagating along such paths. The experiment involved nine microphones on three horizontal booms mounted at different heights to a 135-m meteorological tower at the National Wind Technology Center (Boulder, CO). A ground-based loudspeaker was placed at the base of the tower for vertical propagation or 56m from the base of the tower for slanted propagation. Phasor scatterplots qualitatively characterize the amplitude and phase fluctuations of the received signals during different meteorological regimes. The measurements are also compared to a theory describing the log-amplitude and phase variances based on the spectrum of shear and buoyancy driven turbulence near the ground. Generally, the theory correctly predicts the measured log-amplitude variances, which are affected primarily by small-scale, isotropic turbulent eddies. However, the theory overpredicts the measured phase variances, which are affected primarily by large-scale, anisotropic, buoyantly driven eddies. Ground blocking of these large eddies likely explains the overprediction.

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Numerical model of sonic boom in 3D kinematic turbulence

Cited by 8 publications

References 11 publications

Sonic Boom Prediction and Mitigation using Three-Dimensional Earth Effects

Sonic Boom Prediction and Mitigation using Three-Dimensional Earth Effects

Achievements obtained within ATLLAS-II on Aero-Thermal Loaded Material Investigations for High-Speed Vehicles

Vertical and slanted sound propagation in the near-ground atmosphere : amplitude and phase fluctuations

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