船舶与海洋工程中空泡云的近壁溃灭是空蚀破坏发生的主要原因，为避免空化现象的危害，有必要对复杂几何壁面附近空泡云的溃灭机理、溃灭强度和持续时间进行深入分析。尽管已有的方法可以对单空泡和有限个空化泡的溃灭问题进行直接数值模拟，但在实际问题中空泡云和复杂壁面同时存在，直接数值模拟的难度较大，对数值耗散控制水平、计算稳定性、计算效率以及复杂边界适应能力提出了很高的要求。本课题拟针对上述问题发展模拟空泡云溃灭的高精度差分格式和复杂边界处理策略，突破传统固定网格方法求解包含多尺度、强间断、复杂边界的可压缩多相流问题的局限性，形成一套基于直角自适应网格加密和浸入边界法的空泡云溃灭直接数值模拟工具，通过物理实验数据对求解器可靠性进行全面考核；最后开展空泡云近壁溃灭的高性能数值仿真,从空泡云结构、壁面几何特征等方面分析影响空泡云溃灭的各项因素，初步建立分析复杂壁面空蚀的模型。

Near-wall cloud collapsing is the primary cause for cavitation erosion in naval architecture and ocean engineering. To avoid the cavitation damage, detailed analysis for the collapse mechanism, cavitation strength and duration is required. Although it is feasible to perform Direct Numerical Simulation (DNS) for single or multiple bubble-collapsing, co-exist of cavitation cloud and complex wall boundary greatly increase the difficulty. Numerical schemes should be redesigned to fulfill the requirement of dissipation suppression, numerical stability, computational efficiency and adaption of complex boundary for present DNS. In this project, high-resolution scheme for compressible multiphase flows and a strategy for the treatment of complex boundary will be proposed. A suite of DNS simulator based on adaptive mesh and immersed boundary method will be developed to solve the cavitation flows containing multiscale, strong discontinuity and complex boundary, which is often inefficient by traditional Cartesian solver. The accuracy and reliability of the target DNS simulator will be assessed by physical experiment. Finally, the high-fidelity simulation of near-wall cloud collapsing will be conducted. Essential factors including the bubble configurations, boundary geometry etc. that may affect the bubble collapsing will be fully analyzed, and corresponding theoretical models are going to be established basically to account for the cavitation erosion near complex boundary.