Controlling the development of the turbulent three-dimensional wall jet

控制三维壁射流湍流的发展

• 批准号: 355889-2008
• 负责人: Hall, Joseph
• 金额: $ 1.59万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=504978
• 关键词: Controlling; development; turbulent; three; dimensional

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.

湍流研究具有最大的实际重要性; Holmes等人（2002）提出，“湍流是人类绝大多数能源消耗的原因，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，但描述湍流的方程组并不封闭，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）是一种用于预测湍流行为的常用工具。不幸的是，大多数的程序都是为二维平均流而制定的，即使是轻微的三维流动，也常常产生不令人满意的结果。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，湍流三维壁射流是以强二次流为特征的流动，因此，常规湍流模型不能预测三维壁射流的增长到50%以内。考虑到三维壁射流在工程问题中的频繁出现（即加热通风空调（HVAC）系统、排出物排放、薄膜冷却、翼型设计、电子冷却、燃烧应用以及高速再入飞行器和火箭的外表面冷却），这是特别成问题的。 本研究探讨了三维壁射流中的湍流，希望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理解。