Experimental test of revised similarity hypotheses without Taylor’s hypothesis

摘要

The refined similarity hypotheses (RSH) and their extension to passive scalar (RSH-P) are tested experimentallynusing simultaneous velocity and scalar data in a turbulent jet. Different from the single-point hot-wire probenin a previous experimental test, a combined particle image velocimetry and planar laser induced fluorescencentechnique enable us to obtain the test data without applying Taylor’s hypothesis.RSHis successfully validated withndirect examinations of its three hypotheses. RSH-P is partially supported, where the hypothesis of independentnbehavior of the stochastic variable υθ is not supported. The conditional probability density functions (PDFs) ofnυ and υθ cannot be described by Gaussian distributions when Rer < 5 for υ and Rer < 300 for υθ , and theirnGaussian peaks converge when Rer > 100 for υ and Rer > 1000 for υθ . In addition, the bimodal behavior of thenPDFs and oscillations at small r in previous experimental tests are not observed in this study.