Atomization Process of Liquid Jet with Turbulence Induced by Cavitation

期望提高内燃机的热效率和减少排放。为了阐明液体喷射器喷嘴内的空化现象及其对液体雾化过程的影响，对喷嘴内的空化现象进行了高速可视化和数值模拟。阐明了喷嘴几何形状、喷嘴长径比和非对称流入对空化和排出液体射流的影响。阐明了利用修正空化数可以预测不同几何形状喷嘴中的空化现象。基于LES、气泡跟踪模型和Rayleigh-Plesset方程的数值方法可以模拟喷管内的非定常空化现象。

Improvement in thermal efficiency and reduction in emissions of internal combustion engines are expected. In order to clarify the cavitation taking place in a nozzle of a liquid injector and its effects on liquid jet atomization process, high-speed visualizations and numerical simulations of cavitation in nozzles are carried out. As a result, the effects of geometry, length-to-diameter ratio of nozzles and asymmetric inflow on cavitation and discharged liquid jets are clarified. It is clarified that cavitation in various nozzles with different geometries can be predicted by using a modified cavitation number. Numerical method based on LES, bubble tracking model and Rayleigh-Plesset equation enables us to simulate unsteady cavitation in a nozzle.