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为了研究紊流作用下钝体抖振阻力的空间分布特性及流固相互作用机理,以2∶1矩形断面为例,通过刚性模型测压试验研究了抖振阻力的跨向相关性及空间能量分布特性。结果表明,当紊流积分尺度与钝体特征尺寸相当时,抖振阻力的相关性高于纵向脉动风,这也许是由漩涡沿展向发生拉伸引起。而在分离点附近,来流漩涡会发生剧烈畸变,顺流向大尺度漩涡会破碎成小尺度漩涡,在此过程中能量由低频向高频的转移,并导致脉动压力的跨向相关性也会有所减弱。与迎风侧不同,背风侧脉动压力主要受钝体尾流中的紊流成分影响,其漩涡沿跨向拉伸程度可能要高于迎风侧,以致背风侧脉动压力的跨向相关性强于迎风侧。顺流向分离涡在由分离点向中部运动过程中,其高频的小尺度漩涡可能并没沿顺流向拉伸,而是直接耗散,从而导致脉动压力谱在低频保持不变,而在高频区下降。
In order to study the spatial distribution characteristics of bluff body vibrational resistance and the fluid-solid interaction mechanism under turbulent flow, taking the 2: 1 rectangular section as an example, the cross-directional correlation of vibrational resistance and space energy Distribution characteristics. The results show that when the turbulence integral scale is equal to the size of the bluff body, the correlation of the buffeting resistance is higher than that of the longitudinal fluctuating wind, which may be caused by the stretching of the swirl along the span direction. In the vicinity of the separation point, there will be violent distortion of the incoming vortex. The large-scale whirlpool will break into small-scale whirlpools in the downstream. During this process, the energy is transferred from low frequency to high frequency, and the cross-correlation of the fluctuating pressure will also Weakened. In contrast to the windward side, the leeward-side pulsating pressure is mainly influenced by the turbulent components in the wake of the bluff body, and the extent of the swirl along the span direction may be higher than that on the windward side, so that the cross-directional correlation of the leeward side pulsating pressure is stronger than that of the windward side. Downstream separation vortex In the separation from the point to the middle of the process, the high-frequency small-scale vortex may not be along the flow along the stretch, but directly dissipated, resulting in pulsating pressure spectrum remains unchanged at low frequencies, while in the high The frequency of decline.