非均衡湍流边界层脉动压力测试研究

摘要

Fluctuation pressure test methods for Nonequilibrium turbulence boundary layer are researched, a low noise wind tunnel which provide high measurement signal-to-noise ratio is designed and built. MEMS microphone arrays are used to measure the turbulent boundary-layer fluctuation pressure of 4 wing models with various pressure gradients. Turbulent boundary-layer fluctuation pressure level of wing models with pres-sure gradient is increased by 3-5 dB over that without pressure gradient in low-frequency plateau region. Fitted equations of nonequilibrium turbulence boundary-layer fluctuation pressure spectrum related to Strauhal number, Reynolds number and pressure gradient are regressed with certain applicability. Influence of pressure gradient on turbulence boundary layer fluctuation frequency-wavenumber spectrum is basically below 300 Hz, and the peak spectral level near the transfer wavenumber increase 3-5 dB.%通过建立非均衡湍流边界层脉动压力测试技术及可提供较高测试信噪比的低噪声风洞试验装置，采用表面贴装式硅微传声器线列阵，测量获得了不同压力梯度模型的湍流边界层脉动压力特性，压力梯度模型表面湍流边界层脉动压力低频平台区幅值增加3-5 dB；回归得到了非均衡湍流边界层流脉动压力频谱与Strauhal数及Re数和压力梯度相关的拟合模型，具有一定的适用性；压力梯度对湍流边界层脉动压力频率—波数谱的影响主要集中在300 Hz以下的低频段，传输波数附近峰脊区谱级增加3-5 dB。