Controlling the development of the turbulent three-dimensional wall jet

湍流研究具有极大的实际意义；Holmes等人（2002）认为，“湍流是人类能源消耗的绝大部分原因，包括飞机燃料、管道泵送费用等。”然而，尽管它具有广泛的相关性，但描述湍流的方程集并不是封闭的，并且与湍流相关的现象（如阻力和传热）的预测仍然很困难。计算流体动力学（CFD）是预测湍流行为的常用工具。不幸的是，大多数规范都是针对二维平均流动制定的，并且在甚至轻微的三维流动中往往产生令人不满意的结果。这通常是由于大多数模型无法准确地解释由于湍流的方向性而产生的二次流。例如，湍流三维壁面射流是一种以强二次流为特征的流动，因此，传统的湍流模型无法预测三维壁面射流的增长在50%以内。考虑到在工程问题（即暖通空调（HVAC）系统、污水排放、薄膜冷却、翼型设计、电子冷却、燃烧应用和高速再入飞行器和火箭的外表面冷却）中频繁出现的三维壁面射流，这一点尤其成问题。本文对三维壁面射流中的湍流进行了研究，以期提高我们对湍流产生的二次流及其与流动中有组织的旋涡运动的关系的认识。

Turbulence research is of the greatest practical importance; Holmes et al. (2002) suggested that ''turbulence is responsible for the vast majority of human energy consumption, in aircraft fuel, pipeline pumping charges, and so forth." However, despite its widespread relevance, the equation set describing turbulent flows is not closed and the prediction of phenomena associated with turbulence, such as drag and heat transfer, remains difficult. Computational Fluid Dynamics (CFD) is a commonly used tool for predicting the behaviour of turbulent flows. Unfortunately, the majority of the codes have been formulated for two-dimensional mean flows and often yield unsatisfactory results in flows with even mild three-dimensionality. This is often due to inability of most models to accurately account for the generation of secondary flow due to the directional nature of the turbulence. For example, the turbulent three-dimensional wall jet is a flow that is characterized by strong secondary flows and consequently, conventional turbulence models are unable to predict the growth of three-dimensional wall jets to within 50%. This is particularly problematic given the frequent occurrence of three-dimensional wall jets in engineering problems (i.e. Heating Ventilation Air Conditioning (HVAC) systems, effluent discharge, film cooling, airfoil design, electronics cooling, combustion applications and cooling the outer surfaces of high speed re-entry vehicles and rockets). The present research examines the turbulence in the three dimensional wall jet in the hopes of improving our understanding of turbulence generated secondary flow and its relationship to the organized vortical motions in the flow.