Thermohydrodynamic analysis of micro spherical spiral groove gas bearings under slip flow and surface roughness coupling effect

The effects of gas rarefaction and surface roughness are temperature-related and always neglected in macroscale. These effects were considered in the analysis of the thermohydrodynamic performance of micro spherical spiral groove bearings. The Reynolds equation and the energy equation incorporated with Wu’s slip model and the Weierstrass–Mandelbrot function to analysis the coupling effect of slip flow and surface roughness. The effects of spherical grooves on computational accuracy were reduced through parameter transformation and oblique coordinates. To describe the temperature boundary condition at the grooved region, a simple gas-mixing model was presented for the grooves. Prediction results showed that temperature reduced bearing forces and friction torque through the slip flow effect. Surface roughness increased not only temperature significantly but also bearing forces and friction torque through a high eccentricity ratio and a low bearing clearance.

     

南坪中心枢纽工程施工期间交通组织方案研究

科学合理的交通组织是大型市政工程施工的关键。针对南坪中心枢纽工程的特殊复杂位置与交通流特征,本文研究提出了南坪中心枢纽工程施工期间交通组织方案,并采用VISSIM仿真软件进行优化,动态调整,实施后效果较好,保障了该工程的顺利开展与建成通车。     

超高超大无拉结衬墙单面支模工法

本文针对南坪中心交通枢纽工程模板工程的实际情况,根据作者相关工作经验,对超高超大无拉结侧墙的单面支模技术进行总结,并编制形成单面支模工法。     

城市建设中如何做好管网保护工作

随着城市建设的发展,管网安全对市民生活的影响日益重要.因此,本文针对市政建设中管网破坏的各种原因,根据作者的工作经验,就管网保护工作及方法进行系统地分析.