非均质推进剂燃烧演化模拟:算法与验证

Simulation of the Heterogeneous Propellant Combustion Evolution:Algorithm and Validation

为了研究三维非均质推进剂的燃烧特性,提出了一种基于真实物理结合界面耦合条件的三维空间求解数值框架,气相和固相的演化分别由相互重叠的两套不同网格解析,两相之间通过水平集方法捕捉界面对应的边界条件进行双向耦合,推进剂的非均质颗粒结构由随机填充算法计算生成,在气化过程中气相的质量和能量的守恒通过浸没边界法对相应气相浸没边界网格施加源项以保证。结果表明,随着压强升高(0.69~20.7MPa),空间火焰和燃面温度随之升高,并且燃面更加平整。燃速预测与实验吻合较好,与国外已有平台表现相当,证明使用该计算方法来研究固体燃料燃烧问题的可行性与通用性。

In order to study the combustion characteristics of three-dimensional heterogeneous propellants,a numerical framework for solving three-dimensional space problems based on real physical combined with interface coupling conditions is proposed.The evolution of solid and gas phase is resolved by two differen sets of overlapping grids.The two-way coupling between the solid and gas phase is realized by performing the coundary conditions corresponding to the interface using the level-set method.The heterogeneous particle structure of the propellants is characterized by using a random filling algorithm calculation.The conservation of mass as well as energy in the gasification process can be ensured by imposing appropriate source terms to the corresponding gas phase immersion boundary grids.The results suggest that with increase of environmental pressure(0.69—20.7MPa),the temperatures of the spatial flame and the propellant combustion surface increase,and the combustion suface is smoother.The predicted burning rate results match well with the experimental ones,and the performance is comparable to existing platform abroad,proving the feasibility and universality of the present algorithm method for solid fuel combustion problems.