采用时间分辨立体PIV确定瞬态平面压力场
IntroductionParticle image velocimetry (PIV) has proven its strength as a flow diagnostic tool to characteriseinstantaneous velocity fields and derived quantities such as vorticity. Recent efforts apply momentumconservation principles on planar velocity data in order to extract more quantities, such as pressurefields and integral aerodynamic forces. The theoretical concepts for this 憄lanar pressure imaging?(PPI) have been established and its practical implementation for steady (or time-averaged) flows underapproximately 2D flow conditions has been demonstrated (e.g. Baur and K鰊geter 1999, Gurka et al.1999, Oudheusden et al. 2007). The next challenge is to extend PPI to unsteady flows. This extensioncan be done on basis of time-resolved flow diagnostics such as time-resolved PIV (TR-PIV),cf. Kurtulus et al. 2007. Instantaneous pressure fields are particularly interesting in bluff-body flowsand in fluid-structure interactions, both are important in e.g. wind-engineering applications. A seriouscomplication in extending the planar approach is that flows tend to develop 3D instantaneousstructures even for nominally 2D configurations, especially at larger Reynolds numbers.