LaVision 热成像粒子成像测速系统（PIV）

可同时测量温度场分布和速度场分布。用于空气对流和热交换研究等应用领域。所采用的技术是使用既可以显示提供速度信息又可以提供温度信息的特种热敏感颗粒作为示踪粒子并应用粒子成像测速原理。成像数据的采集为高重复频率具有时间分辨本领。可以研究速度和温度的动态变化过程。

采用LaVision公司的FlowMaster系统测量平面流动的速度场分布，同时用红外相机测量温度场。这对研究热传导机制非常有效。

Impinging synthetic jets are considered as a potential solution for convective cooling, in applications that match their main characteristics (high local heat transfer rates, zero net mass flux, scalability, active control). Nevertheless the understanding of heat transfer to synthetic jets falls short of that available for steady jets. To address this, this paper uses detailed flow field measurements to help identify the main heat transfer mechanisms in impinging synthetic jets. Local heat transfer measurements have been performed for an impinging round synthetic jet at a range of Reynolds numbers between 1000 and 3000, nozzle to plate spacings between 4D and 16D and stroke lengths (L0) between 2D and 32D. The heat transfer results show evidence of distinct regimes in terms of L0/D and L0/H ratios. Based on appropriate scaling, four heat transfer regimes are identified which justifies a detailed study of the flow field characteristics. High speed particle image velocimetry (PIV) has been employed to measure the time-resolved velocity flow fields of the synthetic jet to identify the flow structures at selected L0/H values corresponding to the identified heat transfer regimes. The flow measurements support the same regimes as identified from the heat transfer measurements and provide physical insight for the heat transfer behaviour.