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首页> 外文学位 >Parametric study of thermal and unsteady effects in hydrodynamic lubrication of journal bearings.
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Parametric study of thermal and unsteady effects in hydrodynamic lubrication of journal bearings.

机译：轴颈轴承流体动力润滑中的热和非稳态影响的参数研究。

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摘要

A parametric study of the thermal effects in half-circumferential grooved journal bearings under aligned and misaligned conditions has been carried out by solving numerically the coupled Reynolds and energy equations. Five different sets of boundary conditions for the energy equation have been used which include mixing between recirculating oil and inlet oil and a contraction ratio for the cavitation region. The effects of the wall temperature, of inlet pressure and of the L/D ratio have also been examined. For the ranges of parameters found in internal combustion engines, the mixing effectiveness at the groove and the resulting final mixture temperature as well as the wall temperature and heat transfer rates have been found to be of importance in bearing operations. Realistic inlet pressure increases on the other hand, have been found incapable of affecting significantly the bearing performance. When the journal is misaligned, the variability of the temperature has been shown to smooth out the peaks of both pressure increase and friction caused by misalignment and thus reduce its performance deterioration.; Further, turbulence on the journal bearing operation is examined and the thermal variability is studied for isothermal, convective and adiabatic conditions on the walls. Heat convection is found to play but a small role in determining friction and load. The friction distribution patterns though inside a journal bearing now appear different with high values at the front part of the bearing due to the high speed and low temperature, and a sudden decrease past the pressure maximum.; To examine the unsteady effects of load and shaft speed, a full-circumferential grooved journal bearing under variable load has been analyzed. For this bearing, a series of measurements of shaft speed has just been completed; these data provided the basis for comparison of the numerical results. Thermal effects were not considered because of the short testing time. For this computation, the unsteady Reynolds equation is solved numerically in conjunction with the mobility method and Goenka's map components. The numerical results agree well with the data.
机译：通过数值求解耦合的雷诺兹方程和能量方程，对半周向沟槽轴颈轴承在对准和未对准条件下的热效应进行了参数研究。已经使用了五种不同的能量方程式边界条件集，其中包括循环油和入口油之间的混合以及空化区域的收缩率。还检查了壁温，入口压力和L / D比的影响。对于在内燃机中发现的参数范围，已经发现在凹槽处的混合效率以及所产生的最终混合物温度以及壁温和传热速率在轴承操作中是重要的。另一方面，已经发现实际的入口压力增加不会显着影响轴承性能。当轴颈未对准时，温度的变化已显示出可以消除由于未对准而引起的压力升高和摩擦的峰值，从而减少其性能下降。此外，检查了轴颈轴承运行中的湍流，并研究了壁上等温，对流和绝热条件的热变异性。发现热对流在确定摩擦和载荷方面起着很小的作用。轴颈轴承内部的摩擦分布模式由于高速和低温而在轴承的前部呈现出较高的值，并且在压力最大值之前突然减小。为了检查载荷和轴转速的非稳态影响，分析了可变载荷下的全周槽式轴颈轴承。对于这种轴承，刚刚完成了一系列的轴速测量。这些数据为比较数值结果提供了基础。由于测试时间短，因此未考虑热效应。对于此计算，结合迁移率方法和Goenka的地图分量，对非定常的雷诺方程进行了数值求解。数值结果与数据吻合良好。

著录项

  • 作者

    Chun, Sang Myung.;

  • 作者单位

    Wayne State University.;

  • 授予单位 Wayne State University.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 1989
  • 页码 216 p.
  • 总页数 216
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 机械、仪表工业;
  • 关键词

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