液态铝在纤维预制体中非饱和浸渗的数值模拟

Numerical Simulation of Isothermal Unsaturated Infiltration of Liquid Aluminum into Fiber Preform

为了更加真实地反映液态金属在纤维预制体中的浸渗规律,基于等温浸渗假设模拟了液态铝在纤维预制体中的非饱和渗流行为,研究了非饱和浸渗带内具有不同饱和度的浸渗前沿在渗流过程中的演变规律.模拟结果表明,饱和预制体与未浸渗预制体之间存在一个非饱和浸渗区,非饱和浸渗区的宽度随浸渗时间不断变化.根据预制体中首次达到某饱和度的时间及位置,研究了具有该饱和度的浸渗前沿的运动规律,得出浸渗深度与浸渗时间之间存在平方根关系,这与渗流场分析的理论解是一致的.此模拟方法克服了饱和浸渗假设中浸渗前沿饱和度突变的缺点,更加接近实际情况.

The unsaturated infiltration behavior of melt aluminum into the fiber cake preform under isothermal assumption is investigated numerically, and the evolution of unsaturated infiltration front is explained. The simulation results show that there exists an unsaturated infiltration zone between the saturated and dry performs, and the zone width changes continuously. Although the infiltration front with different saturation moves clown in different way, the infiltration depth is proportional to the square root of infiltration time, which coincides well with the theoretical solution reported. This simulation method of unsaturated infiltration overcomes the shortcoming of the saturated infiltration assumption.