Multi-fidelity Low-boom Design Based on Near-field Pressure Signature

Ueno, Atsushi; Kanamori, Masashi; Makino, Yoshikazu

doi:10.2514/6.2016-2033

Cited by 24 publications

(10 citation statements)

References 7 publications

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“…The JWB design process is described by Ueno, Kanamori, and Makino [63]. The JWB is a wing body configuration designed to the same equivalent area target as the NASA Concept 25D [64].…”

Section: B Jwbmentioning

confidence: 99%

“…The nearfield pressure field of the JWB is shown as the Euler symmetry plane solution in Figure 6. This configuration has a strong expansion surrounding the lower fuselage closeout that is intended to interfere with the shock wave at the rear fuselage [63]. The details of this strong expansion and its interaction with the rear fuselage shock will be shown to be significantly different for RANS simulations.…”

Section: B Jwbmentioning

confidence: 99%

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

Park

Nemec

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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“…The JWB design process is described by Ueno, Kanamori, and Makino [63]. The JWB is a wing body configuration designed to the same equivalent area target as the NASA Concept 25D [64].…”

Section: B Jwbmentioning

confidence: 99%

Section: B Jwbmentioning

confidence: 99%

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

Park

Nemec

2019

Journal of Aircraft

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“…The flight conditions for the JWB are identical to those specified in the Second AIAA Sonic Boom Prediction Workshop [24]. Of particular note is that the reference length, L, for the JWB is not the body length (38.7 m), but rather equal to the body length of the NASA 25D (32.92 m) as used by Park and Nemec [24] and Ueno et al [30]. To study the effectiveness of the near-field splicing method on a perturbed geometry, the baseline JWB geometry was deformed into what will be referred to in this work as the JWB-bump geometry.…”

Section: Tool and Geometry Descriptionsmentioning

confidence: 99%

Near-field Pressure Signature Splicing for Low-Fidelity Design Space Exploration of Supersonic Aircraft

Bolander

Hunsaker

2020

AIAA Scitech 2020 Forum

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Recent efforts to optimize aircraft for drag and loudness have yielded point-designs, which produce the optimal drag and loudness for a specific flight condition [1-3]. When flown at a different flight condition, the aircraft can experience significant increases in loudness or drag depending on the changes in flight and atmospheric conditions. The NASA University Leadership Initiative (ULI) program titled "Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation" (hereafter referred to as "the ULI program") has focused its efforts on expanding the optimal flight envelope of supersonic aircraft through changing the outer mold line (OML) of the aircraft using shape-memory alloys (SMAs). By making small changes or deformations to an aircraft geometry, it has been found that sonic boom loudness can be decreased for off-design flight conditions [4, 5]. Predicting sonic boom loudness follows the procedure outlined in Fig. 1. First, a description of the OML of the aircraft geometry is defined, which is then used in an aerodynamic model to measure pressure perturbations at some radial distance from the center-line of the body. The pressure perturbations are represented in the form of a near-field pressure signature. In three-dimensions, the pressure perturbations create a near-field pressure cone around the aircraft that can be sampled at various azimuthal angles to obtain the slice shown in Fig. 1.

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“…Overall, the on-track signature is more compact than the off-track signatures, which have a strong aft shock. This is likely a consequence of a primarily on-track design [27]. Figure 13 also shows local error estimates for the finest meshes, computed using the technique in Sec.…”

Section: Case Ii: Jaxa Wing-bodymentioning

confidence: 99%

“…It was designed to approximately match an on-track equivalent area distribution derived from the C25 models [27]. Following the approach described in Sec.…”

Section: Case Ii: Jaxa Wing-bodymentioning

confidence: 99%

Cart3D Simulations for the Second AIAA Sonic Boom Prediction Workshop

Anderson

Aftosmis

Nemec

2019

Journal of Aircraft

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Simulation results are presented for all test cases prescribed in the Second AIAA Sonic Boom Prediction Workshop. An inviscid, embedded-boundary Cartesian-mesh flow solver is used to compute "boom carpets"-pressure signatures at a range of specified distances and off-track angles. To accelerate the process, each boom carpet is automatically decomposed into several independent meshes, computed in parallel. Each mesh uses output-based mesh adaptation to affordably obtain credible results. This paper discusses improved Cartesian meshing strategies for boom prediction, including Mach alignment, azimuthal alignment, high-aspect-ratio cells, and adaptation functional weighting. The resulting nearfield signatures generally exhibit good convergence with mesh refinement. For an independent evaluation of our results, this study introduces a local error estimation procedure that highlights regions of the signatures most sensitive to mesh refinement. Results are also presented for the two atmospheric propagation test cases, which investigate the effects of atmospheric profiles on ground noise. Propagation is handled with an augmented Burgers' equation method (NASA's sBOOM), and ground noise metrics are compared.

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Multi-fidelity Low-boom Design Based on Near-field Pressure Signature

Cited by 24 publications

References 7 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

Near-field Pressure Signature Splicing for Low-Fidelity Design Space Exploration of Supersonic Aircraft

Cart3D Simulations for the Second AIAA Sonic Boom Prediction Workshop

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