针对喷水推进器的具体运行环境，拟研究在空化和吸气条件下喷水推进器内和环境两相流动的非定常特性及相应的推力动态特性。采用分段线性界面重构PLIC算法计算自由表面吸气。组合采用PANS方程和传质方程计算空化特性。分两步走的数值计算方法实现了包含自由表面吸气和空化特性的两相流非定常特性计算；在管路回路试验以及静水拖曳水池试验中采用高速摄影和PLIF技术获取非定常流动信息和气相浓度信息，采用专门设计的通气管以及透明箱体对喷水推进器的吸气量进行调节控制和准确测量。应用状态传递函数描述喷水推进器的几何性质以及内部流动结构，应用涡量能量作为判据表征气液两相流动的非定常特性。项目预期揭示喷水推进器在空化和吸气条件下的流动非定常特性及推力的动态特性以及二者的联系，本项目的研究成果可为用于我国高性能船舶的现代喷水推进器研发、为实现高性能船舶高速、高效及稳定控制和巡航提供理论依据。

The unsteady characteristics of waterjet propulsion inner and ambient gas-liquid two phase flow and thrust dynamic features under cavitation and free surface gas entrainment are going to be studied in this project. The piecewise linear interface reconstruction (PLIC) method will be used to simulate the gas entrainment through the free surface, and the partially averaged Navier-Stokes (PANS) equations and mass transfer equation will be combined to calculate the cavitation characteristics. The two simulation steps can accomplish the unsteady gas liquid two phase flow calculation for both cavitation and free surface gas entrainment. A high-speed photography system for the loop test rig and a planar laser induced fluorescence (PLIF) technology for bollard conditions will be performed to obtain the unsteady flow information. A specially designed gas pipe and a transparent and resin housing will be used to control and measure the gas entrainment accurately. Transfer matrix will be calculated according to the pressure date through high frequency sensor and be used to depict the geometry feature and the inner flow structures of the waterjet propulsion. Vortex energy will be used as a threshold criterion to express the unsteady feature of the gas liquid two phase. The efforts will reveal the unsteady characteristics of waterjet propulsion inner and ambient gas-liquid two phase flow and thrust dynamic features under cavitation and free surface gas entrainment as well as their relationship, and the results will afford theoretical and technological support for the modern waterjet propulsion research and development, and for the high speed, high efficient and stable control and cruising of high performance vehicles.