發(fā)布時(shí)間：2018-04-13 13:32

  本文選題：非線性擾動(dòng)方程 + 線性穩(wěn)定性�。� 參考：《計(jì)算力學(xué)學(xué)報(bào)》2017年02期

【摘要】：超音速不穩(wěn)定波是導(dǎo)致剪切流失穩(wěn)和轉(zhuǎn)捩的主要不穩(wěn)定模態(tài),這種模態(tài)以馬赫波的形式輻射到遠(yuǎn)場(chǎng),從而產(chǎn)生強(qiáng)烈的聲場(chǎng)。采用線性穩(wěn)定性理論和非線性擾動(dòng)方程(NLDE)分析,計(jì)算超音速軸對(duì)稱射流不穩(wěn)定波的擾動(dòng)演化(Ma=2.1),對(duì)馬赫波輻射進(jìn)行研究,包括馬赫波輻射方向、輻射源位置,以及隨斯特勞哈爾數(shù)的變化情況。研究結(jié)果表明,在超音速軸對(duì)稱射流中,馬赫波沿固定方向輻射向遠(yuǎn)方,不穩(wěn)定波相位沿另一方向傳播,這兩個(gè)方向相互正交;馬赫波輻射源位置位于不穩(wěn)定波壓力幅值最大處;斯特勞哈爾數(shù)St越大,馬赫波輻射的能力越強(qiáng),輻射區(qū)域越集中。
[Abstract]:Supersonic unstable waves are the main unstable modes leading to shear loss stability and transition, which radiate to the far field in the form of Mahh waves, thus producing a strong sound field.By using the linear stability theory and the nonlinear perturbation equation (NLDED), the perturbation evolution of the unstable waves of the supersonic axisymmetric jet is calculated. The radiation of the Mahh wave is studied, including the direction of the radiation and the location of the radiation source.And with the change of Straugher number.The results show that in the supersonic axisymmetric jet, the Maher wave radiates far along the fixed direction and the phase of the unstable wave propagates in the other direction. The two directions are orthogonal to each other.The location of the Mach wave radiation source is located at the maximum value of the unstable wave pressure, and the greater the Strauher number St, the stronger the ability of the Maher wave radiation and the more concentrated the radiation region.
【作者單位】： 天津大學(xué)機(jī)械工程學(xué)院力學(xué)系;
【基金】：國家自然科學(xué)基金重點(diǎn)項(xiàng)目(11332007);國家自然科學(xué)基金(10972156)資助項(xiàng)目
【分類號(hào)】：O358
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本文編號(hào)：1744737