Modulation of fine-scale velocity gradient phenomena by concurrent large-scale velocity fluctuations in a developed shear flowetc15 Tracking Number 184 Presentation: Session: Jets and Wakes 1 Room: Room E Session start: 10:30 Tue 25 Aug 2015 Oliver Buxton o.buxton@imperial.ac.uk Affifliation: Imperial College London Topics: - Large eddy simulation and related techniques, - Jets and wakes Abstract: The interaction between the large-scale velocity fluctuations (uL) and the small-scale velocity gradient phenomena, such as dissipation and the vortex stretching term, are examined in a turbulent free-shear flow. The difference between the probability density functions of these small-scale quantities conditioned on the sign of uL is quantified by means of the Kullback-Leibler divergence. It is observed that the interaction between uL and the velocity gradient phenomena is maximised at a filter length of 4λ, where λ is the Taylor length-scale. It is postulated that this is consistent with a mean shear mechanism. |