当微尺度气体润滑轴承的间隙达到数nm时,固体表面与气体分子间的Van der Waals力对气体轴承的性能会产生不可忽视的影响。该文假设轴承壁面对气体分子存在Van der Waals作用力,并利用DSMC(direct simulation Monte Carlo)方法结合分子...当微尺度气体润滑轴承的间隙达到数nm时,固体表面与气体分子间的Van der Waals力对气体轴承的性能会产生不可忽视的影响。该文假设轴承壁面对气体分子存在Van der Waals作用力,并利用DSMC(direct simulation Monte Carlo)方法结合分子在表面力作用下的运动算法,研究了该作用力的强度和作用范围对微尺度气体润滑的影响。结果表明:气体轴承中分子密度的分布与不考虑表面力时相比发生了改变,与表面力的作用强度和作用距离有关;壁面的吸引力加剧了分子在壁面附近的聚集,排斥力则相反。展开更多
For comprehensive characteristics of flow in a gas bearing,lattice Boltzmann method(LBM)is applied for study of the two-dimensional flow between two eccentric cylinders with the inner one rotating at a high speed.The ...For comprehensive characteristics of flow in a gas bearing,lattice Boltzmann method(LBM)is applied for study of the two-dimensional flow between two eccentric cylinders with the inner one rotating at a high speed.The flow pattern and circumferential pressure distribution are discussed based on critical issues such as eccentricity ranging from 0.2 to 0.9,clearance ratio varying from 0.005 to 0.01 and rotating speed in the range of 3×104—1.8×105 r/min.The analysis and discussion on the circumferential pressure distribution affirmed the quasilinear relation between the extremum pressure and rotating speed.Furthermore,a high eccentricity and small clearance ratio contributes most to the fluctuation of the circumferential pressure distribution.The flow pattern inside the channel exhibits separation vortex under a large eccentricity.The conclusions drawn in this work give rise to prediction of the flow pattern in the gas bearing which is beneficial for evaluating the performance of as well as instructing the design and development.展开更多
文摘当微尺度气体润滑轴承的间隙达到数nm时,固体表面与气体分子间的Van der Waals力对气体轴承的性能会产生不可忽视的影响。该文假设轴承壁面对气体分子存在Van der Waals作用力,并利用DSMC(direct simulation Monte Carlo)方法结合分子在表面力作用下的运动算法,研究了该作用力的强度和作用范围对微尺度气体润滑的影响。结果表明:气体轴承中分子密度的分布与不考虑表面力时相比发生了改变,与表面力的作用强度和作用距离有关;壁面的吸引力加剧了分子在壁面附近的聚集,排斥力则相反。
基金partially supported by the Aeronautical Science Foundation of China (No.201928052008)
文摘For comprehensive characteristics of flow in a gas bearing,lattice Boltzmann method(LBM)is applied for study of the two-dimensional flow between two eccentric cylinders with the inner one rotating at a high speed.The flow pattern and circumferential pressure distribution are discussed based on critical issues such as eccentricity ranging from 0.2 to 0.9,clearance ratio varying from 0.005 to 0.01 and rotating speed in the range of 3×104—1.8×105 r/min.The analysis and discussion on the circumferential pressure distribution affirmed the quasilinear relation between the extremum pressure and rotating speed.Furthermore,a high eccentricity and small clearance ratio contributes most to the fluctuation of the circumferential pressure distribution.The flow pattern inside the channel exhibits separation vortex under a large eccentricity.The conclusions drawn in this work give rise to prediction of the flow pattern in the gas bearing which is beneficial for evaluating the performance of as well as instructing the design and development.
