Research On The Flow Characteristics Of The Annular Flow In Horizon Pipes Of Oil-air Lubrication System

In recently years, the mechanization is getting a new level and then a series of technical initiatives are needed for improving and keeping the stability and reliability of machines. As one of key factors, the lubrication technology is becoming the focus of researches. Some weakness can’t be ignored in traditional lubrication styles, such as the lubricant can’t be applied totally and can’t be used on a bad condition. The oil-air lubrication technology gets a right solution for those problems and makes it be widely applied in metallurgical machinery, steel rolling machinery and so on. However, the researches on the mechanism of oil-air lubrication are so limited that to delay the development of its application. Therefore, we take the mechanism of the oil-air lubrication as a subject in this thesis for more wide application of the oil-air lubrication.According to the working condition of the oil-air lubrication, the theory and the software of computational fluid dynamics have been taken as tools to analyze the characteristics of oil-air annular flow in a horizon pipe and in a suddenly expending pipe, and then some results are obtained as flows,(1) The mechanism of shaping to annular flow in oil-air lubrication system is categorized, and a new style of oil-air mixture has been given out for improving the performance of the air-oil mixer.(2) The distribution of pressure along a horizon pipe has been collected from the results calculated by the Chisholm’theory with a modifying constant c and simulated by the Fluent software. The relations between the speed of air and the distribution of the pressure have been found, and the results from the theory and the simulation results from Fluent have a quantitative consistency.(3) The thickness of oil film along the pipe has been collected for analyzing the distribution of oil in the oil-air annular flow, and the relation between the speed of air and the distribution of oil has been got. The results are shown that the speed of air is larger and the fluctuation of the oil film is more obvious. (4) The characteristics of the oil-air annular through the suddenly expending pipe have been analyzed in the last thesis. The distribution characteristics of the pressure, oil and velocity in this kind of suddenly expending pipes have been analyzed.