Scattering Experiments in Turbulent Rayleigh-Benard Convection

9312398 Tong本项目将利用激光散射技术研究水中湍流瑞利-贝纳德（Rayleigh-Benard， RB）对流的局部速度、相对速度和局部涡度场的统计特性。实验的目的是发现和测试湍流核心区域和热粘边界层附近不同瑞利数和长度尺度上的速度和涡量统计的标度规律。将特别注意速度波动的间歇性以及相干结构与速度和涡度的概率密度函数之间的相互关系。该项目将提供一组可靠的数据来检验目前关于RB湍流对流的理论。速度和涡量测量将补充大量的温度测量。本项目将利用激光散射技术研究热对流湍流运动的统计特性。该项目对于理解热湍流的基本统计特性具有重要意义，并且与许多有效传热的技术应用有关。理解紊流对流中的热传输现象可以为这个问题提供新的线索，可能会导致从核反应堆的热交换到再入飞行器的各种工业应用的技术改进。＊＊＊

9312398 Tong The research described in this project will utilize laser light scattering techniques to study statistical properties of the local velocity, the relative velocity and the local vorticity fields of turbulent Rayleigh-Benard (RB) convection in water. The experiments will aim at finding and testing scaling laws if velocity and vorticity statistics over varying Rayleigh numbers and length scales in the turbulent core region and near thermal and viscous boundary layers. Special attention will be given to the intermittent nature of velocity fluctuations and to correlations between coherent structure and the probability density functions for the velocities and the vorticity. The project will provide a body of reliable data to test current theories for turbulent RB convection. The velocity and vorticity measurements will complement a wealth of temperature measurements. %%% This project will utilize laser light scattering techniques to study statistical properties of turbulent motion in thermal convection. The project is of fundamental interest for understanding the basic statistical properties of thermal turbulence, and it is also relevant to many technological applications for effective heat transfer. Understanding heat transport phenomena in turbulent convection can shed new light on the subject potentially lead to technological improvements in various industrial applications ranging from heat exchanges in nuclear reactors to reentry vehicles. ***