유동과 레이저 유도 플라즈마 사이의 상호작용 정량화

Laser ignition has become an attractive research topic because of its possibility to replace the conventional spark plug in both automotive and aircraft engines fields with an increasing demand of high efficiency and low emission. The laser ignition system is known to reduce the flame propagation time and increase the combustion efficiency, which could be used for ignition of lean-fuel mixtures or in high speed combustion system. However, few results are available as far as the quantitative interaction between the laser induced plasma and its consequence to the surrounding flow. On this study, the effect of laser-induced plasma on gaseous flow is quantified. Based on Particle Image Velocimetry (PIV), it is possible to measure the change of velocity fields of seeded air flow near laser-induced plasma. This velocity information is further processed to determine the characteristic time of the system influenced by laser-induced plasma, to analyze the deviation of trajectories of virtual particles affected by laser-induced plasma, and finally to obtain instantaneous angle which can characterize the influence of laser-induced plasma. By this process, the interactions between flow and laser-induced plasma can be quantitively described.