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该文推导了开孔双空腔结构内压动力响应的方程组,得到了共振频率和等效阻尼比。对不同空腔开孔面积比和内部容积比下模型各空腔的内压动力响应进行了风洞试验。研究结果表明:两空腔结构模型进行风洞试验时空腔的内部容积,应按照原型和实验风速比平方的关系进行调整以准确模拟原型的内压脉动。含有外墙开孔的空腔(前腔)内压脉动均方根小于不含外墙开孔的空腔(后腔)。内外压均方根比会随着空腔开孔面积比的增加而增大。另外,空腔开孔面积比的增加还会导致系统共振频率升高,等效阻尼比降低。而空腔容积比的增加会使一阶共振频率升高,二阶共振频率降低,并趋向单一空腔时的Helmholtz频率。
In this paper, we derive the equations of the internal pressure response of the double-cavity with openings, and obtain the resonance frequency and the equivalent damping ratio. Wind tunnel tests were carried out on the internal pressure dynamic responses of the cavities under different cavity opening area ratio and internal volume ratio. The results show that the internal volume of cavity in wind tunnel test of two cavity model should be adjusted to accurately simulate the internal pressure pulsation of the prototype according to the relationship between the prototype wind speed and the square of experimental wind speed. The root mean square root of the internal pressure pulsation in the cavity with the hole in the outer wall (front cavity) is smaller than that in the cavity without the hole in the outer wall (the back cavity). Internal and external pressure root mean square ratio will increase with the cavity opening area ratio increases. In addition, the increase of cavity opening area ratio also leads to the increase of system resonance frequency and the decrease of equivalent damping ratio. The cavity volume ratio will increase the first-order resonance frequency, the second-order resonance frequency decreases, and tends to a single cavity Helmholtz frequency.