【摘要】 动态气动力的研究是实验工作者极为关注的问题。特别对于二元模型动态气动力的测定,必须从脉动的压力分布通过面积加权积分来得到气动力的时间历程,而其先决条件为各测压点压力的时间历程必须是同步的,也就是要测得同一时刻诸多测点的压力。本文介绍了一种比较经济的多点同步测压方法,并对该方法的实施进行了探讨。分别对A/D卡采样的同步性、整套测压系统的同步性以及频响特性进行了测试和验证。经相关性分析,相关系数分别达到0. 9999和 0. 99。最后以圆柱表面脉动压力系数分布的测试为例,给出了单圆柱不同瞬间的压力向量图、按照瞬间压力沿表面积分得到的单个圆柱脉动升力的时间历程,以及升力的脉动频率,表明整套同步测压系统具有很好的实用性,能满足实验的需要。更多还原

【Abstract】 In this paper, a method for simultaneous multi-pressure measurement concerned by many researchers was described in detail. The time series of fluctuating forces of 2-dimensional model can be only got from the integration of fluctuating pressure distribution, which demands the simultaneous measurements of all the pressure taps. The simultaneousness of the A/D card and the whole measurement system were tested, and the correlation coefficients were 0.9999 and 0.99 respectively. As an application of the method, the measurements of fluctuating pressure distribution for a circular cylinder were carried out in a low-speed wind tunnel. The instantaneous pressure vector maps at different moments and the time series of fluctuating lift integrated by fluctuating pressure distribution were illustrated. The frequency of fluctuating lift is consistent with that of fluctuating pressure measured at one tap. All these prove that the whole system is available for simultaneous measurements.更多还原