A reconstruction method is proposed for the polyurethane foam and then a complete numerical method is developed to predict the effective thermal conductivity of the polyurethane foam. The finite volume method is appli...A reconstruction method is proposed for the polyurethane foam and then a complete numerical method is developed to predict the effective thermal conductivity of the polyurethane foam. The finite volume method is applied to solve the 2D heterogeneous pure conduction. The lattice Boltzmann method is adopted to solve the 1D homogenous radiative transfer equation rather than Rosseland approximation equation. The lattice Boltzmann method is then adopted to solve 1D homogeneous conduction-radiation energy transport equation considering the combined effect of conduction and radiation. To validate the accuracy of the present method, the hot disk method is adopted to measure the effective thermal conductivity of the polyurethane foams at different temperature. The numerical results agree well with the experimental data. Then, the influences of temperature, porosity and cell size on the effective thermal conductivity of the polyurethane foam are investigated. The results show that the effective thermal conductivity of the polyurethane foams increases with temperature; and the effective thermal conductivity of the polyurethane foams decreases with increasing porosity while increases with the cell size.展开更多
The structural design of asphalt foaming device, the determination of foam chamber process and condition parameters are the key technologies to foaming effect of foam asphalt. In this paper, we analyze the research st...The structural design of asphalt foaming device, the determination of foam chamber process and condition parameters are the key technologies to foaming effect of foam asphalt. In this paper, we analyze the research status of foaming mechanism, foaming device design and determination of the various parameters. The paper puts forward opinions for asphalt foaming technology. And development trend of the asphalt foaming technology is analyzed.展开更多
基金Funded by Key Project of International Joint Research of National Natural Science Foundation of China(No.51320105004)
文摘A reconstruction method is proposed for the polyurethane foam and then a complete numerical method is developed to predict the effective thermal conductivity of the polyurethane foam. The finite volume method is applied to solve the 2D heterogeneous pure conduction. The lattice Boltzmann method is adopted to solve the 1D homogenous radiative transfer equation rather than Rosseland approximation equation. The lattice Boltzmann method is then adopted to solve 1D homogeneous conduction-radiation energy transport equation considering the combined effect of conduction and radiation. To validate the accuracy of the present method, the hot disk method is adopted to measure the effective thermal conductivity of the polyurethane foams at different temperature. The numerical results agree well with the experimental data. Then, the influences of temperature, porosity and cell size on the effective thermal conductivity of the polyurethane foam are investigated. The results show that the effective thermal conductivity of the polyurethane foams increases with temperature; and the effective thermal conductivity of the polyurethane foams decreases with increasing porosity while increases with the cell size.
基金Foundation of Xi'an Science Plan(CX12180(4))the Special Fund for Basic Scientific Research of Central Colleges of Chang’an University(CHD2010JC092)
文摘The structural design of asphalt foaming device, the determination of foam chamber process and condition parameters are the key technologies to foaming effect of foam asphalt. In this paper, we analyze the research status of foaming mechanism, foaming device design and determination of the various parameters. The paper puts forward opinions for asphalt foaming technology. And development trend of the asphalt foaming technology is analyzed.
