Acoustic Phenomena from Correctly Expanded Supersonic Jet Impinging on Inclined Plate
Acoustic Phenomena from Correctly Expanded Supersonic Jet Impinging on Inclined Plate
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正确扩展的超音速射流撞击斜板的声学现象
DOI：
10.2514/1.j053953
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
S. Tsutsumi
中科院分区：
文献类型：
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作者：
Masahito Akamine;Y. Nakanishi;K. Okamoto;S. Teramoto;Takeo Okunuki;S. Tsutsumi
排气羽流声波引起的有效载荷振动是运载火箭升空过程中的一个重大问题。这些声波被认为是由射流撞击地面或发射台的火焰偏转器以及来自自由射流区域引起的。因此，地面坡度或火焰偏转器轮廓被认为会影响这种声学现象的强度和特征，但抑制声波产生的设计原理尚未建立，因为射流冲击产生的声波的产生机制尚未充分阐明。因此，本研究通过使用射流设施进行的实验，研究了正确扩展的超音速射流撞击倾斜平板时的声学现象。超音速射流撞击固体表面的流场已在许多先前的研究中得到检验。例如，Donaldson 和 Snedecker [1] 描述了基本的流程结构。根据他们使用膨胀不足的射流以不同角度撞击垂直或倾斜板的实验，流动结构被解释为由具有不同流态的三个区域组成：自由射流、冲击和壁射流区域。自由射流区域受射流冲击的影响最小，并且就潜在的核心层和超音速剪切层而言，其流动结构与自由射流相似。接下来，射流撞击在板上，在撞击区域中产生再循环流，最后，射流在壁射流区域中沿着板表面流动。 Carling 和 Hunt [2] 通过实验讨论了正确膨胀的射流撞击垂直板的流场，并观察了板表面上的一系列膨胀、再压缩，以及在某些情况下的冲击波。对于冲击斜板的欠膨胀射流，Lamont 和 Hunt [3] 的实验以及 Kim 和 Chang [4] 的计算中观察到了冲击区域的复杂激波结构。该结构由板激波（即，对峙激波）和围绕板激波的附加尾部激波组成。中井等人。 [5]通过实验将这种结构在不同的板角度、喷嘴-板距离和压力比条件下分为四种类型。此外，McIlroy 和 Fujii [6] 给出了这种激波结构的详细数值描述。对于相关声学现象的研究，以往的研究大多集中在离散音调噪声上。实验研究（例如，[7,8]）和最近的数值研究（例如，[9,10]）讨论了声学特性和相关的垂直射流冲击流现象，同时，Risborg 和 Soria [11] 通过可视化声波讨论了冲击倾斜板上的欠膨胀射流的声反馈回路。至于对正确扩展的超音速射流撞击倾斜板的声学现象的研究，即本研究中研究的主题，可以找到一些数值报告，例如[12-14]。这些研究旨在研究运载火箭升空过程中的声学现象，并讨论了冲击区域中包含复杂冲击结构的声场和流场。特别是，这些研究结果表明存在两种类型的声波：来自超音速湍流壁射流的马赫波，以及沿近似垂直于板的方向传播的声波。 Nonomura 等人还计算了各种冲击条件下的声场。 [14] 和本田等人。 [15]但是，另一方面，只有[16]可以作为这些现象的实验研究。他们测量了Mj 1.5正确展开的喷气机在两个固定位置撞击斜板的噪声，主要关注航空母舰甲板的噪声环境。他们成功揭示了喷嘴-板距离和射流温度对声压级 (SPL) 的影响，同时他们还指出，进一步的研究，例如 SPL 的空间分布、声源区域的定位和光学测量，可能有助于全面表征声学和流动特性。如上所述，已经对这些声学现象进行了详细的数值研究，但目前缺乏基于实验数据的讨论。详细的实验结果对于声学现象的讨论是必不可少的，因为通过数值分析获得的频谱的频率范围存在限制。因此，本研究的目的是通过实验研究正确膨胀的超音速射流撞击倾斜板时的声波特性。为了实现这一目标，使用射流设施中的麦克风测量来自撞击射流的声波。然后使用纹影方法将波可视化，并在本研究中讨论它们的传播方向、频谱和源区域的范围。在评估 SPL 测量的准确性并确认射流剖面（在第 II.D. 节中描述）后，在第 II.D. 节中介绍了基于 SPL 测量和纹影可视化结果的声场概述。 III.A.然后，声波的频谱在第二节中讨论。 III.B.最后，在第 2 节中，使用 SPL 分布和纹影可视化电影分析来讨论声波源区域的范围。 III.C. 2014 年 9 月 26 日收稿； 2014 年 11 月 4 日收到修订； 2014 年 11 月 4 日接受出版； 2015 年 1 月 28 日在线发布。版权所有© 2014，Masahito Akamine。由美国航空航天研究所经许可出版。本文件的副本可供个人或内部使用，但复印者需向版权清算中心有限公司 (Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923) 支付每份 10.00 美元的费用；包括代码 1533-385X/15 和与 CCC 对应的 10.00 美元。 *先进能源系研究生。学生会员AIAA。博士先进能源系学生；目前就职于 IHI 公司。先进能源系副教授。美国汽车协会会员。航空航天系副教授。 AIAA 高级会员。航空航天系高级工程师。 **JAXA 工程数字创新 (JEDI) 中心工程师。美国汽车协会会员。
PAYLOAD vibration due to acoustic waves from the exhaust plume is a significant problem during the liftoff of a launch vehicle. These acoustic waves are considered to be caused by jet impingement on the ground or on the flame deflector at the launch pad, as well as being from the free jet region. The ground slope or flame deflector profiles are therefore considered to affect the intensity and characteristics of this acoustic phenomenon, but design principles to suppress acoustic wave generation have not yet been established, because the generation mechanisms of the acoustic waves from the jet impingement have not been sufficiently clarified. Therefore, this study investigates the acoustic phenomena from a correctly expanded supersonic jet impinging on an inclined flat plate, through experiments conducted using a jet facility. The flow field of a supersonic jet impinging on a solid surface has been examined in many previous studies. For example, the fundamental flow structure was described by Donaldson and Snedecker [1]. From their experiments using an underexpanded jet impinging on a perpendicular or inclined plate at various angles, the flow structure was explained as being composed of three regions with different flow regimes: the free jet, impingement, and wall jet regions. The free jet region is minimally affected by the jet impingement, and its flow structure is similar to that of a free jet, as regard the potential core and supersonic shear layers. Next, the jet impinges on the plate, yielding a recirculation flow in the impingement region while, finally, the jet flows along the plate surface in the wall jet region. Carling and Hunt [2] experimentally discussed the flow field of a correctly expanded jet impinging on a perpendicular plate, and observed a series of expansion, recompression, and, in some cases, shock waves on the plate surface. As for an underexpanded jet impinging on an inclined plate, complicated shock structure in the impingement regionwas observed in the experiments of Lamont and Hunt [3], and in the calculations of Kim and Chang [4]. This structure is composed of plate shocks (i.e., standoff shocks) with additional tail shocks around the plate shocks. Nakai et al. [5] experimentally classified this structure into four types under various plate angle, nozzle–plate distance, and pressure ratio conditions. Moreover, a detailed numerical description of this shock structure was given by McIlroy and Fujii [6]. As for the investigation of the related acoustic phenomena, most previous studies have focused on discrete tone noise. The acoustic characteristics and the related perpendicular jet impingement flow phenomena were discussed in experimental studies (e.g., [7,8]) and recent numerical works (e.g., [9,10]), while, also, Risborg and Soria [11] discussed the acoustic feedback loop of an underexpanded jet impinging on an inclined plate by visualizing acoustic waves. As for studies on the acoustic phenomena from a correctly expanded supersonic jet impinging on an inclined plate, the subject that is examined in the present study, several numerical reports can be found, such as [12–14]. These studies were conducted to investigate the acoustic phenomena during the liftoff of a launch vehicle, and also discussed the acoustic and flow fields, which contain complex shock structures in the impingement region. In particular, the results of these studies revealed that there exist two types of acoustic waves: the Mach waves from the supersonic turbulent wall jet, and the acoustic waves propagating in an approximately perpendicular direction to the plate. The acoustic field under various impingement conditions was also calculated by Nonomura et al. [14] and Honda et al. [15] but, on the other hand, only [16] can be found as an experimental study of these phenomena. They measured noise from Mj 1.5 correctly expanded jets impinging on inclined plates at two fixed locations, mainly focusing on the noise environment of an aircraft carrier deck. They successfully revealed the influence of the nozzle–plate distance and the jet temperature on the sound pressure level (SPL), whereas they also noted that further investigations, such as spatial distribution of SPL, localization of the source region, and optical measurements, may be useful to fully characterize the acoustic and flow properties. As described above, these acoustic phenomena have been investigated numerically in detail, but discussion based on experimental data is currently lacking. Detailed experimental results are indispensable to a discussion of acoustic phenomena, because a limitation in the frequency range of the spectra obtained by numerical analyses exists. Therefore, the objective of the present study is to study the characteristics of the acoustic waves from a correctly expanded supersonic jet impinging on the inclined plate experimentally. To achieve this, the acoustic waves from the impinging jet are measured using a microphone at a jet facility. The waves are then visualized using the schlieren method, and their propagation directions, spectra, and the extent of the source region are discussed in this study.After an evaluation of the accuracy of the SPLmeasurement and confirmation of the jet profile (described in Sec. II.D.), an overview of the acoustic field based on the results of the SPL measurements and schlieren visualization is presented inSec. III.A. Then, the spectra of the acoustic waves are discussed in Sec. III.B. Finally, the extent of the source region of the acoustic waves is discussed using the SPL distributions and a schlieren visualization movie analysis, in Sec. III.C. Received 26 September 2014; revision received 4 November 2014; accepted for publication4November 2014; published online 28 January 2015. Copyright© 2014byMasahitoAkamine. Published by theAmerican Institute of Aeronautics and Astronautics, Inc., with permission. Copies of this paper may be made for personal or internal use, on condition that the copier pay the $10.00 per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923; include the code 1533-385X/15 and $10.00 in correspondence with the CCC. *Graduate Student, Department of Advanced Energy. Student Member AIAA. Ph.D. Student, Department of Advanced Energy; currently at IHI Corporation. Associate Professor, Department of Advanced Energy. Member AIAA. Associate Professor, Department of Aeronautics and Astronautics. Senior Member AIAA. Senior Engineer, Department of Aeronautics and Astronautics. **Engineer, JAXA’s Engineering Digital Innovation (JEDI) Center. Member AIAA.