主管部门: 中国航天科技集团有限公司
主办单位: 中国航天空气动力技术研究院
中国宇航学会
中国宇航出版有限责任公司

ρ-VOF:一种可清晰模拟自由界面的两相流方法

ρ-VOF: a Method for Simulating Sharp Free Interface in Gas-Liquid Flow

  • 摘要: 文章通过对EFM(effective field modeling)模型进行简化, 消除了原模型的非守恒性项和非双曲性特性项, 发展了一种基于密度的气液两相流模拟方法: ρ-VOF方法.利用体积分数信息对控制单元内的自由界面进行重构, 得到了控制单元内流体的空间分布, 并采用AUSM+-up格式获得考虑气液流体接触间断信息的对流通量.新方法可统一处理激波间断和接触间断的相互作用, 保持自由界面的尖锐性, 并且其计算量与自由界面的空间复杂度无关.最后, 数值模拟了液体激波管气液激波管和气体激波跨二维液滴传播等问题, 并与文献结果进行对比, 验证了本方法在气液两相流模拟中的准确性.

     

    Abstract: A new density based numerical simulation method, named ρ-VOF, was developed for gas-liquid flow. The governing equation originated from the simplified EFM (effective field modeling)model, in which, the items of nonconservation and nonhyperbolicity in the original equation were removed. The free interface in the control volume was reconstructed, according to the volume fraction field. Also, the spatial distribution of the fluids in the control volume was achieved. AUSM+-up scheme was applied to calculate the convective fluxes and pressure fluxes, taking consideration of the contact discontinuity of the free interface. The new method is capable of simulating the interaction between shock discontinuity and contact discontinuity uniformly and maintaining the sharpness of the free interface. Also, the cost in calculation is independent of the complexity of the free interface. At the last part, typical examples of gas-liquid flow were simulated, such as shock in liquid tube problem, shock in gas-liquid tube problem and shock passing by a two-dimensional droplet problem. Comparing the current results with the published data, the validity of ρ-VOF was confirmed.

     

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