Numerical Optimization of Fuselage Geometry to Modify Sonic-Boom Signature

Makino, Yoshikazu; Aoyama, Takashi; Iwamiya, Toshiyuki; Watanuki, Tadaharu; Kubota, Hirotoshi

doi:10.2514/2.2509

Cited by 21 publications

(7 citation statements)

References 10 publications

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13] There are also many examples of conceptual aircraft design reports where the authors described going "deep" in a particular discipline, focusing on a single cruise point low-boom and/or low-drag design in their process. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Many of these are often byproducts of tool and method development and the testing of optimization algorithms and/or schemes. There are fewer instances focused on supersonic design for low-boom concepts with shape optimization tied to overall vehicle performance.…”

Section: Introductionmentioning

confidence: 99%

Integration of Multifidelity Multidisciplinary Computer Codes for Design and Analysis of Supersonic Aircraft

Geiselhart

Ozoroski

Fenbert

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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This paper documents the development of a conceptual level integrated process for design and analysis of efficient and environmentally acceptable supersonic aircraft. To overcome the technical challenges to achieve this goal, a conceptual design capability which provides users with the ability to examine the integrated solution between all disciplines and facilitates the application of multidiscipline design, analysis, and optimization on a scale greater than previously achieved, is needed. The described capability is both an interactive design environment as well as a high powered optimization system with a unique blend of low, mixed and high-fidelity engineering tools combined together in the software integration framework, ModelCenter. The various modules are described and capabilities of the system are demonstrated. The current limitations and proposed future enhancements are also discussed. = equivalent area C L = lift coefficient dp/p = (the calculated pressure -the ambient pressure)/(the ambient pressure) EXTR = extraction ratio FPR = fan pressure ratio L/D = lift to drag ratio nmi = nautical miles OPR = overall pressure ratio OML = outer mold line SFC = specific fuel consumption T 3 = compressor exit temperature, °R T 4 = combustor exit temperature, °R TTR = throttle ratio V app = approach velocity, kts V jet = jet velocity, ft/s

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Section: Introductionmentioning

confidence: 99%

Integration of Multifidelity Multidisciplinary Computer Codes for Design and Analysis of Supersonic Aircraft

Geiselhart

Ozoroski

Fenbert

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

View full text Add to dashboard Cite

show abstract

“…7 shows the sonic boom signatures calculated without atmospheric turbulence using the nearfield pressure signatures at h=l 1:0-5:0. This is shown because the accuracy of sonic boom calculation is dependent on confirmation of the grid dependency and the three-dimensional effect of the flow [31]. As shown Fig.…”

Section: A Determination Of the Near-field Pressure Wave For Sonic Bmentioning

confidence: 93%

“…We calculated the A-weighted sound exposure level (ASEL) on the following three signatures: the no-turbulence case, the turbulence case with maximum overpressure, and the turbulence case with minimum overpressure. To estimate the rise time of the respective sonic boom signatures, we employed the rise time prediction model [31,32], based on the three series, the molecular absorption theory, the empirical model, and the outer boundary of the flyover data; each series represents the rise time as a function of shock overpressure P. For the rise time calculation for three signatures, we added the estimated rise time to the respective sonic boom signatures on the ground by assuming the straight line approximation from the onset of shock to shock maximum and shock minimum to the end of the shock. Table 1 shows the resulting ASEL values for the three cases.…”

Section: B Variability Of Sonic Boom Overpressurementioning

confidence: 99%

Sonic Boom Variability Due to Homogeneous Atmospheric Turbulence

Yamashita

Obayashi

2009

Journal of Aircraft

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This study describes the nondeterministic effect of homogeneous atmospheric turbulence on sonic boom propagation. The Sears-Haack body was calculated in three dimensions by computational fluid dynamics in inviscid flow (Euler) mode to create the near-field pressure wave. The homogeneous atmospheric turbulence field was represented by the finite sum of discrete Fourier modes based on the von Karman and Pao energy spectrum. The sonic boom signature was then calculated by the modified waveform parameter method, considering a random velocity of homogeneous atmospheric turbulence. The results of this study indicated that atmospheric turbulence has a marked influence on sonic boom overpressure during its propagation to the ground. In comparison to the noturbulence condition, we found that the sonic boom decreased in 59% of the cases and increased in 41% of the cases. Thus, homogeneous atmospheric turbulence seems to favor a decrease, rather than an increase, in boom overpressure. In addition, we found that turbulence has a small effect on the propagation path from the flight altitude to the ground. Nonetheless, this small change in the propagation path may result in a variability, of the point at which the sonic boom reaches the ground, of up to 1820 ft in the north-south direction (flight direction) and 115 ft in the east-west direction.

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“…14, 20, 21, 23, 29.) The most detailed description was given by Makino et al, 29 who used 14 numerical optimization iterations to modify 8 control points of a B-spline representation of the fuselage geometry over the selected segments of the fuselage. Recently, Makino and Kroo 39 used an Akima spline representation of the radius distribution of an axisymmetric fuselage with seven control points for sonic-boom minimization using genetic algorithms.…”

Section: Interactive Optimization For Matching Equivalent Area Dismentioning

confidence: 99%

“…Later, Makino et al 29 used numerical optimization of fuselage geometry of the low-boom baseline discussed in ref. 10 to modify the sonic-boom signature predicted by Thomas's code using a near-field pressure distribution at six body lengths.…”

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confidence: 99%

Interactive Inverse Design Optimization of Fuselage Shape for Low-Boom Supersonic Concepts

Shields

2008

46th AIAA Aerospace Sciences Meeting and Exhibit

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There are several research papers on how to design a supersonic configuration that has desirable low-boom characteristics as determined by the Seebass-George-Darden boom minimization theory (SGD theory). The low-boom signatures predicted by the SGD theory could be realized by wing-fuselage configurations. However, for a given low-boom signature generated by the SGD theory, it is still an open question whether one could develop a feasible aircraft configuration with nacelles and tails that has a similar low-boom ground signature as that predicted by the SGD theory.Past attempts indicated that no feasible aircraft configuration with nacelles and tails would have a total equivalent area distribution matching one of the equivalent area distributions corresponding to the low-boom ground signatures determined by the SGD theory. There are essentially three alternative methods for generating a supersonic concept with a shaped boom ground signature: (i) use a direct optimization method that minimizes numerical figures of merit for low-boom characteristics, (ii) construct new "realizable" target equivalent area distributions (or near-field pressure distributions) that result in shaped boom ground signatures, and (iii) develop new tools to help designers find acceptable low-boom configurations. There were many attempts, with mixed results, using the first two methods to obtain supersonic configurations that have shaped boom ground signatures.This paper introduces a tool called BOSS (Boom Optimization using Smoothest Shape modifications). BOSS utilizes interactive inverse design optimization to develop a fuselage shape that yields a low-boom aircraft configuration. The paper also demonstrates how BOSS could be used to help design realistic aircraft concepts with low-boom ground signatures. A fundamental reason for developing BOSS is the need to generate feasible low-boom conceptual designs that are appropriate for further refinement using CFD-based preliminary design methods. BOSS was not developed to provide a numerical solution to the inverse design problem. Instead, BOSS was intended to help designers find the "right" configuration among infinitely many possible configurations that are equally good using any numerical figure of merit.BOSS uses the smoothest shape modification strategy for modifying the fuselage radius distribution at 100 or more longitudinal locations to find a smooth fuselage shape that reduces the discrepancies between the design and target equivalent area distributions over any specified range of effective distance. For any given supersonic concept (with wing, fuselage, nacelles, tails, and/or canards), a designer can examine the differences between the design and target equivalent areas, decide which part of the design equivalent area curve needs to be modified, choose a desirable rate for the reduction of the discrepancies over the specified range, and select a parameter for smoothness control of the fuselage shape. BOSS will then generate a fuselage shape based on the designer's inputs in a matter ...

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Numerical Optimization of Fuselage Geometry to Modify Sonic-Boom Signature

Cited by 21 publications

References 10 publications

Integration of Multifidelity Multidisciplinary Computer Codes for Design and Analysis of Supersonic Aircraft

Integration of Multifidelity Multidisciplinary Computer Codes for Design and Analysis of Supersonic Aircraft

Sonic Boom Variability Due to Homogeneous Atmospheric Turbulence

Interactive Inverse Design Optimization of Fuselage Shape for Low-Boom Supersonic Concepts

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