应用粒子成像测速技术测量压力振荡器的瞬态流场

利用以两台大功率脉冲激光器为双脉冲光源的粒子成像测速 (PIV)技术 ,测定了驻波管型正弦压力振荡器二维振荡射流瞬态流场 ,对示踪粒子的跟随性进行了比较 ,分析了示踪粒子在流场中的浓度分布对成像质量的影响。实验结果表明 ,环形喷嘴射流与尖劈之间存在交错的、方向相反的旋涡是使整个系统产生流体自激振荡的原因 ,环形喷嘴与尖劈之间的距离对瞬态流场有明显的影响。由双脉冲激光作光源的PIV系统具有脉冲间隔调节范围宽、测量精度高等特点 ,非常适合于从低速到高速全范围的流场测量

MEASUREMENT OF INSTANTANEOUS FLOWFIELD IN PRESSURE OSCILLATOR USING PARTICLE IMAGE VELOCIMETRY

The two\|dimensional instantaneous velocity field of sinusoidal pressure generator with standing wave tube is measured by particle image velocimetry (PIV) technology with double\|pulsed lasers as lamp\|house. The characteristics of three kinds of tracer particles to follow the flow are compared. The influence of concentration of tracer particles in flow on particle image quality is analyzed. The experimental results show that there are two interlaced vortexes which rotates in opposite directions in flowfield between the nozzle and the splitter. The interaction between the moving vortex and the standing tube causes the self\|excitation of the pressure generator. The gap between nozzle and splitter has influence on the instantaneous flow field. The PIV system with double\|pulse laser as lamp\|house has a wide adjusting range of pulse interval and high precision. It is very appropriate for measuring flow field in which the velocity ranges from low to high.