亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

The size of turbulence is of great significance to the accuracy of numerical calculation. In addition, the variation of gas-liquid two-phase mixed density in the cavitation zone has a great influence on the cavitation development process. In order to investigate the effect of turbulence models on numerical simulation of cavitating flows in thermo-fluids, combined filter-based model (FBM) with density-corrected model (DCM), three turbulence models (k-ε, RNG k-ε and SST k-ω) were modified based on the local mesh size and the density of vapor-liquid mixture. The original turbulence models and modified models were used in the numerical simulation of single-phase flow and gas-liquid two-phase flow around the NACA0015 hydrofoil in varying temperatures water. The numerical results were compared with experimental data. The results showed that the modified k-ε model eliminated the effect of turbulence scale. In addition, the law of development of cavity was well consistent with the experimental results, according to the results calculated by the modified RNG k-ε model. The modified RNG k-ε revealed the law of cavitation with temperature variation simultaneously, i.e. as the temperature of the fluid increased, the vapor volume fraction was decreased, the cavitation intensity was weakened, and the cavity area became smaller. The adverse pressure gradient became smaller in the closed region of the cavity tail, and the gas-liquid interface became blurred, which reflected better corrected effect. According to validation calculations and composite comparison with the experiment, the modified RNG k-ε was applicable for numerical simulation of gas-liquid two-phase flow in thermo-fluids which can provide theoretical basis and guidance for numerical simulation of low temperature thermal cavitating flow.