方管湍流具有比其它管道流动更加复杂的湍流特征，其独特的截面二次流动、湍流转捩与壁面拟序结构协同作用致使其中颗粒运动更加复杂。近年来，随着方管湍流转捩现象的发现，为全面研究方管湍流中颗粒在多种效应下复杂运动提供了重要的理论支持。目前，方管中湍流转捩、二次流动、与壁面拟序结构协同作用下颗粒运动特征及机理的研究还鲜见报道。项目申请人基于多年来在方管多相湍流领域工作积累，提出该项目研究计划，包括方管湍流转捩、二次流动、以及近壁面拟序结构, 多效应协同作用下的颗粒物扩散、沉淀、卷起等行为。应用数值计算与实验测量相结合的方法, 全面研究方管湍流多效应协同作用下颗粒物运动机理。分析方管湍流二次流动、湍流转捩以及壁面拟序结构，寻求颗粒行为特征与湍流多效应间的关联性，探究颗粒存在对湍流各效应的反作用，最终获得方管湍流多种效应协同作用下颗粒运动机理。

Compared to other flows, turbulence in square duct flows is the most complex one because it includes secondary flow, turbulence transition and coherent structure near the wall. As such, particles in the square duct turbulent flows look very comprehensive. In recent years, with the discovery of turbulence transition in the duct flows, the investigation of particle behaviour under the combined effects of the turbulence in duct flows has been expansively developed. So far, the investigation of the joined effect of turbulence transition, secondary flow in combination of coherent structure on particle behaviour has never been found. The applicant has done series of research in the area of multiphase duct flows for years and proposed to study the joined effect of turbulence transition, secondary flow and coherent structure on particle behaviour (such as dispersion, deposition, resuspension and so on) in the turbulent duct flows. This work will be carried out by numerical simulation and experimental measurement. Understanding of secondary flow, turbulence transition and coherent structure contributes to discover the linkage between particle behaviour and turbulent flows as well as its feedback to turbulence. In the end, the working mechanism of multiple effect of turbulence on particle behaviour in duct flows will be obtained.