Study of Hydrodynamic Lubication Mechanism based on the Theory of Turbulence

基于湍流理论的流体动力润滑机理研究

基本信息

批准号：
61460101
负责人：
NAKABAYASHI Koichi
金额：
$ 3.97万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-61460101/
关键词：
Fluid Mechanics Turbulrnt Flow Lubrication Couette Flow Sinusoidally Waved wall Pressure Gradient Inertia Effect 非平衡乱流乱流クエット流波状壁乱流

项目摘要

First of all, turbulent plane Couette flow has been experimentally investigated to consider the structure of turbulent lubrication in an unloaded journal bearing. Mean velocity and turbulence have been measured in essentially fully developed flow from laminar to turbulent region. Mean velocity profiles are compared with theoretical profiles and the results of direct numerical simulation in the transition region. In the fully developed turbulent region, the velocity follows the logarithmic velocity profile U^+=2.5lny^++ 5.1 obtained by telbany and Reynolds in the wall region but outside the buffer layer layer, and the velocitybany and the velocity-defect law (U_c-U)/u*=R_f(1-y/h) in the core region, where U_c, u* and h are centerline vrlocity, friction velocity and half channel depth, respectively. Skin friction coefficient, turbulence intensity, Reynolds shear-stress and energy-density spectra are also discussed in comparison with the other results obtained previously.Subsequently, the … More structure of turbulent flow in the lubrication for the eccentricity ratio m=0.3 in a loaded journal bearing has been experimentally investigated in the two-dimensional channel between a sinusoidally waved wall and a plane noving belt. The flow is accelerated and decelerated in the main flow direction with the pressure gradient alternating in sign,so that the turbulence is in disequilibrium and greatly influenced by the inertia effect of the flow. The velocity profiles in the wall region are displaced above the logarithmic velocity profile of the turbulent Ciuette flow, depending on y^+ and x/1 (x=coordinate in the direction of main flow ; 1=one wavelength of sinusoidally waved wall). The value of U^+ in the wall region can be given by the function of both Van Driest damping constant A^+ and Karman constant k, which depend on a perssure gradient parameter <nu>dp/dx/(<rho>u*^3) and an inertia effect parameter. Half-power law and velocity defect law were also found in the gradient layer and the core region, respectively. Distribution of Reynolds shera-stress is much influenced by the inertia effect of normal velocity component caused by the secondary flow. Turbulence in tensities,ROO<<U'^2>> and √<V'^2>, were also measured and discussed. Less

首先，已经对湍流平面的凝血流进行了研究，以考虑在未载的期刊轴承中湍流润滑的结构。在从层流到湍流区域的完全发展的流动中，已经测量了平均速度和湍流。将平均速度曲线与理论谱和过渡区域中直接数值模拟的结果进行比较。 In the fully developed turbulent region, the velocity follows the logarithmic velocity profile U^+=2.5lny^++ 5.1 obtained by telbany and Reynolds in the wall region but outside the buffer layer layer, and the velocity-defect law (U_c-U)/u*=R_f(1-y/h) in the core region, where U_c, u* and h are centerline vrlocity, friction速度和半通道深度。与先前获得的其他结果相比，还讨论了皮肤摩擦系数，湍流强度，雷诺剪切压力和能量密度光谱。随后，在载荷轴承中，在两种效果之间，在载荷轴承中对偏心率m = 0.3的曲折性比率m = 0.3的湍流结构进行了……在两种方向孔之间进行了实验。该流量在主要流动方向加速和减速，并具有符号的压力梯度替代方案，因此湍流是在拆卸中的，并且受湍流的影响很大，墙面区域中的速度分布位于上方的速度谱位于对数速度的上方，这取决于y^+和x/x/x/x = kirortion coverion coeortion ciuette流的速度。正弦波挥舞墙）。壁区域中的U^+的值可以通过van Driest阻尼常数A^+和Karman常数k的功能，这取决于perssure梯度参数<nu> dp/dx/（<ho> u*^3）和惯性效应参数。在梯度层和核心区域中也发现了半功率定律和速度缺陷定律。雷诺的分布shera应力受到次级流量引起的正常速度成分的惯性效应的影响很大。还测量并讨论了紧张局势的湍流，Roo << u'^2 >>和√<v'^2>。较少的