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Measurements of second-mode instability waves in hypersonic boundary layers with a high-frequency pressure transducer.

機(jī)譯：用高頻壓力傳感器測量高超聲速邊界層中的第二種模式不穩(wěn)定性波。

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摘要

Measurements of the instabilities which lead to transition are important for the development of improved models for predicting transition. At hypersonic speeds, these measurements are often difficult and have typically required the use of hot wires, which are too fragile to be used in many hypersonic wind tunnels. Recent work has shown that PCB-132 piezoelectric pressure transducers are capable of measuring the second-mode instability. These sensors are robust and could be used in many hypersonic tunnels, but are not yet calibrated for instability measurements.;An attempt was made to calibrate the sensors with an existing shock tube. The sensors were found to have a linear response over the range that was tested, though some indications of nonlinear behavior were observed. Attempts to determine a model for the sensors were unsuccessful. A new shock tube is being designed and built for the purpose of calibrating these sensors.;Measurements on a 7° half-angle cone were made in the AEDC Hypervelocity Wind Tunnel 9, the Langley 15-Inch Mach-6 Hi-Temperature Tunnel, and the Langley 31-Inch Mach-10 Tunnel. Second-mode waves were measured in all of these tunnels for the first time. Growth, saturation, and breakdown were observed in each tunnel, and the saturation amplitude was observed to increase with Mach number. Adding an isolated roughness was seen to reduce the amplitudes observed and cause breakdown to occur sooner. The effects of non-zero angle of attack were also investigated. Measurements of the freestream fluctuations with the PCB-132 sensors showed signal above the electronic noise at the second-mode frequencies. This is the first time that measurements of acoustic noise at the second-mode frequencies have been available.
機(jī)譯：導(dǎo)致過渡的不穩(wěn)定性的度量對于開發(fā)用于預(yù)測過渡的改進(jìn)模型非常重要。在高超聲速下，這些測量通常很困難，并且通常需要使用熱線，因為它們太脆弱了，無法在許多高超聲速風(fēng)洞中使用。最近的工作表明，PCB-132壓電壓力傳感器能夠測量第二模式的不穩(wěn)定性。這些傳感器堅固耐用，可以在許多高超音速隧道中使用，但尚未針對不穩(wěn)定性測量進(jìn)行校準(zhǔn)。試圖用現(xiàn)有的激波管對傳感器進(jìn)行校準(zhǔn)。盡管觀察到一些非線性行為的跡象，但發(fā)現(xiàn)傳感器在測試范圍內(nèi)具有線性響應(yīng)。嘗試確定傳感器的模型失敗。為了校準(zhǔn)這些傳感器，正在設(shè)計和制造新的減震管。在AEDC超高速風(fēng)洞9，Langley 15英寸Mach-6高溫隧道，AEDC超高速風(fēng)洞9中對7°半角錐進(jìn)行了測量，和蘭利31英寸馬赫10隧道。首次在所有這些隧道中測量了第二模式波。在每個隧道中觀察到生長，飽和和擊穿，并且觀察到飽和幅度隨馬赫數(shù)增加?？梢钥吹皆黾庸铝⒌拇植诙瓤梢詼p小觀察到的振幅，并導(dǎo)致?lián)舸└彀l(fā)生。還研究了非零迎角的影響。使用PCB-132傳感器對自由流波動進(jìn)行的測量表明，在第二模式頻率下，信號高于電子噪聲。這是首次在第二模式頻率下進(jìn)行聲學(xué)噪聲測量。

著錄項

  • 作者

    Berridge, Dennis C.;

  • 作者單位

    Purdue University.;

  • 授予單位 Purdue University.;
  • 學(xué)科 Engineering Aerospace.
  • 學(xué)位 M.S.A.A.
  • 年度 2010
  • 頁碼 196 p.
  • 總頁數(shù) 196
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類
  • 關(guān)鍵詞

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