DLR TAU Simulations for the Second AIAA Sonic Boom Prediction Workshop

Kirz, Jochen; Rudnik, Ralf

doi:10.2514/1.c034819

“…This includes all the participant presentations, computational grids, and submitted results to encourage continued research. Workshop participants also published details of their analysis in conference papers organized into an invited special session at the AIAA AVIAITON 2017 conference with this summary [2,[10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Nearfield Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

Park

¹

,

Nemec

²

2019

Journal of Aircraft

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A summary is provided for the Second AIAA Sonic Boom Workshop held 8-9 January 2017 in conjunction with AIAA SciTech 2017. The workshop used three required models of increasing complexity: an axisymmetric body, a wing body, and a complete configuration with flow-through nacelle. An optional complete configuration with propulsion boundary conditions is also provided. These models are designed with similar nearfield signatures to isolate geometry and shock/expansion interaction effects. Eleven international participant groups submitted nearfield signatures with forces, pitching moment, and iterative convergence norms. Statistics and grid convergence of these nearfield signatures are presented. These submissions are propagated to the ground, and noise levels are computed. This allows the grid convergence and the statistical distribution of a noise level to be computed. While progress is documented since the first workshop, improvement to the analysis methods for a possible subsequent workshop are provided. The complete configuration with flow-through nacelle showed the most dramatic improvement between the two workshops. The current workshop cases are more relevant to vehicles with lower loudness and have the potential for lower annoyance than the first workshop cases. The models for this workshop with quieter ground noise levels than the first workshop exposed weaknesses in analysis, particularly in convective discretization. * Research Scientist, Computational AeroSciences Branch, Mike.Park@NASA.gov, AIAA Senior Member. † Aerospace Engineer, Computational Aerosciences Branch, Marian.Nemec@NASA.gov, AIAA Senior Member.

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“…This study does not consider aeroelastic effects, change in operation conditions, and the secondary effects of air property fluctuations with latitude and longitude at cruise altitude. Consequently, all sonic boom evaluations herein use the same near-field pressure signature that is provided by the 2nd AIAA SBPW [26]. The retrieved pressure signature is five body lengths away from the aircraft (the aircraft is 32.9 m long).…”

Section: A Fluid Dynamicsmentioning

confidence: 99%

“…Because the definition of an "acceptable" boom remains open for debate, many studies (led primarily by NASA Langley Research Center) have analyzed to what degree humans are annoyed by sonic booms at ground level [21][22][23][24][25]. The perceived level and associated annoyance are related to the peak overpressure and shock rise time of the ground signature [5], but other factors such as subject location (outdoors vs indoors) [19], position in the boom carpet (i.e., area affected by the boom) [26], aircraft maneuvers [27], and flyover frequency [20] are also significant. Because of all the factors that can influence the perception of a sonic boom, rigorous studies are necessary to investigate the sound pressure level and the perceived level of any given SST in a realistic atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Effects of Atmospheric Profiles on Sonic Boom Perceived Level from Supersonic Vehicles

Leal¹,

Schrass²,

Giblette³

et al. 2021

AIAA Journal

5

0

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U.S. national research priorities include reducing the disruption caused by sonic booms, which hindered the economic viability of supersonic aircraft in decades past. However, shock waves are unavoidable during supersonic flight; and exposure of people, animals, and structures to these shock waves on the ground cannot be eliminated entirely. It is herein shown that changing atmospheric conditions, gusts, and heights above ground can result in any supersonic aircraft that is acceptably quiet at specific atmospheric conditions becoming uncomfortably loud in other flight conditions. These performance variations are noticeable for periods ranging from 12 h to one year across the continental United States of America. Therefore, strategies to actively mitigate sonic booms may become necessary as researchers work toward resumption of overland commercial supersonic flight.

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“…DLR-TAU has also been applied to the SBPW1 cases [35]. Details of the DLR-TAU application to SBPW2 are available in [10]. Two reconstruction limiters were used: DLR-TAU-V used the Venkatakrishnan limiter [36] and DLR-TAU-BJ used the Barth-Jespersen limiter [37].…”

Section: Participantsmentioning

confidence: 99%

Near Field Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

Park

¹

,

Nemec

²

2017

35th AIAA Applied Aerodynamics Conference

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A summary is provided for the Second AIAA Sonic Boom Workshop held 8-9 January 2017 in conjunction with AIAA SciTech 2017. The workshop used three required models of increasing complexity: an axisymmetric body, a wing body, and a complete configuration with flow-through nacelle. An optional complete configuration with propulsion boundary conditions is also provided. These models are designed with similar nearfield signatures to isolate geometry and shock/expansion interaction effects. Eleven international participant groups submitted nearfield signatures with forces, pitching moment, and iterative convergence norms. Statistics and grid convergence of these nearfield signatures are presented. These submissions are propagated to the ground, and noise levels are computed. This allows the grid convergence and the statistical distribution of a noise level to be computed. While progress is documented since the first workshop, improvement to the analysis methods for a possible subsequent workshop are provided. The complete configuration with flow-through nacelle showed the most dramatic improvement between the two workshops. The current workshop cases are more relevant to vehicles with lower loudness and have the potential for lower annoyance than the first workshop cases. The models for this workshop with quieter ground noise levels than the first workshop exposed weaknesses in analysis, particularly in convective discretization.

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DLR TAU Simulations for the Second AIAA Sonic Boom Prediction Workshop

Cited by 16 publications

References 21 publications

Nearfield Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

Nearfield Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

Effects of Atmospheric Profiles on Sonic Boom Perceived Level from Supersonic Vehicles

Near Field Summary and Statistical Analysis of the Second AIAA Sonic Boom Prediction Workshop

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