通过一维杆的一维传热的分组显式数值求解,分析热弹性效应的存在及规律,得出随着时间的增长,温升—热变形之间的关系会逐渐趋近稳态,但不可能获得绝对的稳态;在传热过程中,随着距离增加,温度衰减很快,离热源越远的点的热弹性效环应越窄...通过一维杆的一维传热的分组显式数值求解,分析热弹性效应的存在及规律,得出随着时间的增长,温升—热变形之间的关系会逐渐趋近稳态,但不可能获得绝对的稳态;在传热过程中,随着距离增加,温度衰减很快,离热源越远的点的热弹性效环应越窄。提出用非线性时序模型与前向神经网络相结合的模型(Nonlinear auto-regressive moving average neural network with exogenousinputs,NARMAX-NN)来辨识热弹性效应。用NARMAX-NN模型对高速进给系统试验台的热动态特性进行建模,获得良好的效果。此方法比多变量回归模型、反馈神经网络模型及广义最小二乘输出误差模型有更好的精度和鲁棒性,能精确地对复杂结构、多热源的时变非线性热误差特性进行建模和预测。展开更多
The thermoelastohydrodynamic performance of an inclined-ellipse dimpled gas face seal is analyzed. The pressure distributions of the gas film and temperature fields of the seal rings and gas film are presented conside...The thermoelastohydrodynamic performance of an inclined-ellipse dimpled gas face seal is analyzed. The pressure distributions of the gas film and temperature fields of the seal rings and gas film are presented considering thermal and elastic distortions.Then, the influences of texturing parameters, including dimple inclination angle and dimple depth, on sealing performance are investigated under different operating parameters such as rotational speeds and seal pressures. The results show that face distortions lead to a decrease in the hydrodynamic effect at high rotational speed. The analysis shows that the opening force can decrease by more than 50% as the rotational speed increases from 0 to 35000 r min^(-1). The influence of face distortion on the seal performance, such as opening force and leakage characteristic, gradually increases with the rotational speed.展开更多
文摘通过一维杆的一维传热的分组显式数值求解,分析热弹性效应的存在及规律,得出随着时间的增长,温升—热变形之间的关系会逐渐趋近稳态,但不可能获得绝对的稳态;在传热过程中,随着距离增加,温度衰减很快,离热源越远的点的热弹性效环应越窄。提出用非线性时序模型与前向神经网络相结合的模型(Nonlinear auto-regressive moving average neural network with exogenousinputs,NARMAX-NN)来辨识热弹性效应。用NARMAX-NN模型对高速进给系统试验台的热动态特性进行建模,获得良好的效果。此方法比多变量回归模型、反馈神经网络模型及广义最小二乘输出误差模型有更好的精度和鲁棒性,能精确地对复杂结构、多热源的时变非线性热误差特性进行建模和预测。
基金supported by the National Natural Science Foundation of China(Grant No.51275473)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LR14E050001)
文摘The thermoelastohydrodynamic performance of an inclined-ellipse dimpled gas face seal is analyzed. The pressure distributions of the gas film and temperature fields of the seal rings and gas film are presented considering thermal and elastic distortions.Then, the influences of texturing parameters, including dimple inclination angle and dimple depth, on sealing performance are investigated under different operating parameters such as rotational speeds and seal pressures. The results show that face distortions lead to a decrease in the hydrodynamic effect at high rotational speed. The analysis shows that the opening force can decrease by more than 50% as the rotational speed increases from 0 to 35000 r min^(-1). The influence of face distortion on the seal performance, such as opening force and leakage characteristic, gradually increases with the rotational speed.
