Fluid Mechanics Research

拟议工作的具体目标是：a)研究多结构湍流，记录能量耗散的标度，并仔细检查湍流理论中基本假设的正确性；b)研究自由流中各向异性剪切湍流与静止或移动壁面产生的湍流之间的相互作用；c)记录湍流结构、旁路过渡和再区域化、集中源的标量输送、壁面传热和内部物体在时间加速和减速时的涡脱；D)将泰勒湍流扩散理论推广到发展中和多结构流动，设计优化标量扩散和混合的条件，并研究Schmidt/Prandtl数对标量精细结构和微分扩散发展的影响；e)实验研究横向和流向扰动影响下的涡稳定性和破裂，详细记录湍流自由流中流向涡和相干结构之间的相互作用；f)修改现有的模拟循环系统，使其重现生理性冠状动脉流动，并收集针对人工心脏瓣膜不同方位的冠状动脉入口附近解剖模型的速度测量结果。

The specific objectives of the proposed work are: a) to investigate multi-structure turbulence, to document the scaling of energy dissipation and to scrutinize the validity of fundamental assumptions in turbulence theory; b) to study the interaction between anisotropic, sheared turbulence in the free stream and turbulence generated by a stationary or moving wall; c) to document the turbulence structure, by-pass transition and relaminarisation, scalar transport from concentrated sources, heat transfer from the wall and vortex shedding from internal objects in temporally accelerating and decelerating channel flows; d) to extend Taylorian turbulent diffusion theory to developing and multi-structure flows, to devise conditions that optimize scalar diffusion and mixing and to investigate the effect of Schmidt/Prandtl number on the scalar fine structure and the development of differential diffusion; e) to study experimentally vortex stability and breakdown under the influence of transverse and streamwise disturbances, and to document in detail the mutual interactions between a streamwise vortex and coherent structures in a turbulent free stream; f) to modify an existing mock circulation loop so that it reproduces physiological coronary flows and to collect velocity measurements in an anatomical model of the aorta near the coronary inlet for different orientations of a prosthetic heart valve.