排序方式: 共有95条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
According to control theories, mine fires can be considered as an unsteady process after the normal ventilation system is disturbed. Applied the principal of physical chemistry and thermal fluid mechanics, the parameters models of the unsteady state system have been given, such as fuel combustion rate, heat of combustion, concentration, temperature, heat losses, heat resistance, work of expansion and heat pressure difference. The results of the calculation agree approximately with the results of the test. By the computer simulation, it is shown that the main factor of producing the throttling effect is the fire rate, second is the heat resistance and the heat pressure difference. The rate of heat flow that passes through the airway wall is the maximum on the surface, and decrease with time. The heat transfer progresses only within the range of 0..5 m away from theairway wall during combus-tion for 2 hours. It‘s variable for the mass flux rate and the percentage concentration of the gas along the airway of the downstream. When the delayed time is very small, the varidtion can be neglected. Viscosity resistance is the main part of the heat resistance, second is the expansion resistance that is less than tens Pascal when Mach number is very small. Work of expansion is principally tumed into heat losses, only a very small part is consumed by the work of the heat resistance and the inertia acceleration. 相似文献
5.
6.
7.
8.
9.
10.
计算直喷式柴油机螺旋进气道与缸内空气运动的大型微机化程序:IPIC-CFD(Ⅱ) 总被引:1,自引:0,他引:1
使用IPIC-CFD程序在国内首次对直喷式柴油机螺旋进气道-进气门-气缸内空气运动进行了稳流和实机三维数值模拟.并运用激光多普勒(LDA)技术对稳态进气过程中的空气运动进行测试,验证了所建模型的精度和可靠性. 相似文献