海域天然气水合物空化喷嘴内流场数值模拟

Numerical Simulation of the Flow Field in the Cavitation Nozzle for Marine Gas Hydrate

针对海域天然气水合物水射流破碎开采,对角形喷嘴、亥姆霍兹喷嘴、锥形喷嘴开展天然气水合物储层条件下空化效果对比,并深入研究进口压力、出口压力对亥姆霍兹喷嘴空化特性的影响。建立喷嘴内流场的数学模型和物理模型,采用流体仿真软件进行数值模拟,以气含量作为判断空化效果的主要依据开展研究。模拟结果表明:天然气水合物储层条件下,亥姆霍兹喷嘴空化性能优于角形喷嘴和锥形喷嘴,喷嘴内部最大气含量达到0.95;保持其他条件不变,进口压力越大,亥姆霍兹喷嘴产生的空化效果越好;天然气水合物储层的高压环境会产生阻滞作用,降低亥姆霍兹喷嘴空化性能。

Considering the water jet crushing exploitation of marine gas hydrate,the cavitation effects of angle nozzle,Helmholtz nozzle and conical nozzle under the conditions of natural gas hydrate reservoir were compared,and the influence of both inlet and outlet pressure on cavitation characteristics of Helmholtz noz-zle was investigated,including having mathematical model and physical model of the flow field in the nozzle established,and the fluid simulation software adopted for the numerical simulation and the gas content based to judge cavitation effect.The simulation results show that,the cavitation performance of Helmholtz nozzle outperforms that of both angle nozzle and conical nozzle under the condition of natural gas hydrate reservoir.The maximum gas content inside the nozzle reaches 0.95.When other conditions keep unchanged,the greater inlet pressure brings about better cavitation effect produced by Helmholtz nozzle;the high-pressure gas hydrate reservoir produces blocking effect and reduces cavitation performance of Helmholtz nozzle.