临近空间低雷诺数螺旋桨翼型与桨叶非定常机制及控制研究

项目名称： 临近空间低雷诺数螺旋桨翼型与桨叶非定常机制及控制研究

项目编号： No.11302177

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 许建华

作者单位： 西北工业大学

项目金额： 28万元

中文摘要： 低雷诺数层流分离泡会导致螺旋桨绕流与气动力呈现非定常/非线性特征，对该现象的流动机理和物理机制认识不足是临近空间螺旋桨气动效率难以显著提高的重要原因。现有风洞实验技术很难完全模拟临近空间低压低密度环境，而含层流分离泡的流动转捩判断是目前数值方法尚未完全解决的难点问题。本项目拟在提高流动求解精度的基础上，采用数值方法开展低雷诺数非定常流动机制及控制方法研究。主要研究内容为：1）适用于含层流分离泡流动的转捩判断模型研究；2）深入分析翼型低雷诺数层流分离泡的形成、演变和稳定性等行为特征，揭示翼型低雷诺数流动的非定常机制。深入探讨翼型几何外形对非定常机制的影响规律，并开展翼型低雷诺数非定常机制的控制方法研究；3）探讨螺旋桨桨叶低雷诺数层流分离泡在离心力作用下的行为特征，揭示桨叶旋转效应对低雷诺数流动的影响规律。通过上述研究，为临近空间高效螺旋桨气动设计提供精确分析方法和科学依据。

中文关键词： 低雷诺数；螺旋桨；临近空间；非定常机制；非定常控制

英文摘要： The laminar separation bubble at low Reynolds number makes the flow around propellers and corresponding aerodynamic performance behave unsteady/nonlinear characteristics. But the knowledge about the flow mechanism and the physical mechanism of this phenomenon is rather few, which is an important reason for the difficulty to improve the aerodynamic efficiency of propellers in near space. Unfortunately, it is almost impossible to completely simulate the near space environment with low pressure and low density by wind tunnel test, while there are also key issues on transition prediction model in numerical methods. In this project, accurate numerical methods are used to simulate the unsteady flow at low Reynolds number and investigate the flow control method. The researches are mainly consist of: 1) several transition models for flow with laminar separation bubbles will be studied; 2) the characteristics of laminar separation bubbles on airfoils at low Reynolds number will be deeply analyzed, including the generation and evolvement history, the stability characteristics and the unsteady mechanism. The rules of how airfoil geometry influences unsteady mechanism will be also explored, and the study of how to control these unsteady mechanism for airfoils will be carried out at low Reynolds number; 3) the characters of

英文关键词： low Reynolds number；propeller；near space；unsteady mechanism；unsteady mechanism control