Particle Response to Fluid Turbulence: A Novel Approach to Measuring in the Particle-Lagrangian Coordinate System

这是C.罗杰斯（塔夫茨大学）和J.伊顿（斯坦福大学）的合作项目。提出了一种实验与数值模拟相结合的方法，将LDV系统的测量控制体积视为湍流场中的粒子。LDV系统将使用一个主动控制回路。将确定粒子-拉格朗日参考系中流体速度的自相关性，以及同一点上粒子和流体的波动速度之间的相关性。所获得的数据与直接数值模拟的结果相似，而直接数值模拟目前只适用于低雷诺数的湍流。所得结果对两相流的理论和数值模拟具有一定的指导意义。简化了实验条件：只模拟点颗粒，颗粒不影响流动，测试域为二维，考虑颗粒形状和尾迹的影响。本项目可能会在理解和模拟各种工业过程中感兴趣的高雷诺数分散两相流方面取得重大进展。

This is a collaborative project between C. Rogers (Tufts U.) and J. Eaton (Standford U.). A combined experimental-numerical simulation approach is proposed to displace the masuring control volume of an LDV system as it were a particle in a turbulent field. The LDV system will use an active control loop. The fluid velocity autocorrelations in a particle-Lagrangian reference frame, and the correlations between the fluctuating velocities of the particle and the fluid at the same point, will be detrmined. The obtained data are similar to the results derived from direct numerical simulations, which currently are feasible only at turbulent flow with low Reynolds numbers. The results may be useful to calibrate various theories and numerical simulations in tow phase flows. The conditions of the experiment are simplified: only point particles are simulated, particles do not affect the flow, the testing domain is two- dimensional, the effects of particle shape and wake are considered. The present project may lead to significant advances in understanding and modeling disperse two-phase flow at high Reynolds numbers of interest in various industrial processes.