沥青发泡腔结构参数对腔内流场的影响

Effects of Structural Parameters of Asphalt Foaming Chamber on Its Inner Flow Field

基于沥青发泡的原理和行为特点,采用单因素分析法用CFD软件模拟了腔体内沥青发泡的过程,分析了腔体容积、沥青入口尺寸、泡沫沥青出口尺寸对腔体内部温度场、压力场和速度场的影响规律,并运用灰色系统理论探寻主要结构参数与腔内流场间的数值关系.结果表明,腔体容积为2V、沥青入口为0.71Q、泡沫沥青出口为0.75D(V,Q,D分别为三者的基准尺寸),可获得适宜的沥青发泡腔体内部流场;腔体容积、沥青入口尺寸、泡沫沥青出口尺寸与腔内压力场的关联度分别为0.56,0.64,0.53,与腔内速度场的关联度分别0.68,0.71,0.72,与腔内温度场的关联度分别为0.75,0.71,0.70,沥青入口尺寸是影响腔内压力场和温度场的主导因素,泡沫沥青出口尺寸是影响腔内速度场的主导因素.

Single factor analysis method was used to simulate the foaming process of asphalt with CFD software. The primary structural parameters of foaming chamber, such as chamber volume, asphalt entrance size and foamed asphalt outlet size, were taken as simulating variables. And their effects on the temperature, pressure and velocity fields in the chamber analyzed. Then the grey related degree method was applied to analyze the relationship between the structural parameters of chamber and its internal flow field. The results show that the velocity, pressure and temperature fields of the cavity are much better for asphalt foaming when the chamber volume is 2V, asphalt entrance size 0.71 Q and outlet size 0.75D（V, Q and D are the basic dimensions of parameters）. In the sequence of chamber volume, entrance size and outlet size, the correlation degree between the parameters and internal pressure field are 0.56, 0.64 and 0.53, the correlation degree between the parameters and internal flow velocity field 0.68, 0.71 and 0.72, and the correlation degree between the parameters and internal temperature field 0.75, 0.71 and 0.70, respectively. These imply that the asphalt entrance size has the biggest effect on the internal pressure and temperature fields of the chamber, and the foamed asphalt outlet size the biggest effect on the internal velocity field of the chamber.