In this section
@article{Craske:2015:10.1017/jfm.2015.417,
author = {Craske, J and Debugne, ALR and van, Reeuwijk M},
doi = {10.1017/jfm.2015.417},
journal = {Journal of Fluid Mechanics},
pages = {28--51},
title = {Shear-flow dispersion in turbulent jets},
url = {http://dx.doi.org/10.1017/jfm.2015.417},
volume = {781},
year = {2015}
}
TY - JOUR
AB - We investigate the transport of a passive scalar in a fully developed turbulent axisymmetric jet at a Reynolds number of Re = 4815 using data from direct numerical simulation. In particular, we simulate the response of the concentration field to an instantaneous variation of the scalar flux at the source. To analyse the time evolution of this statisticallyunsteady process we take an ensemble average over 16 independent simulations. We find that the evolution of Cm(z, t), the radial integral of the ensemble-averaged concentration, is a self-similar process, with front position and spread both scaling as √t. The longitudinal mixing of Cm is shown to be primarily caused by shear-flow dispersion.Using the approach developed by Craske & van Reeuwijk (J. Fluid Mech., vol. 763, 2014,pp. 538–566), the classical theory for shear-flow dispersion is applied to turbulent jets to obtain a closure that couples the integral scalar flux to the integral concentration Cm. Model predictions using the dispersion closure are in good agreement with the simulation data. Application of the dispersion closure to a two-dimensional jet results in an integraltransport equation that is fully consistent with that of Landel et al. (J. Fluid Mech., vol.711, 2012, pp. 212–258)
AU - Craske,J
AU - Debugne,ALR
AU - van,Reeuwijk M
DO - 10.1017/jfm.2015.417
EP - 51
PY - 2015///
SN - 0022-1120
SP - 28
TI - Shear-flow dispersion in turbulent jets
T2 - Journal of Fluid Mechanics
UR - http://dx.doi.org/10.1017/jfm.2015.417
UR - http://hdl.handle.net/10044/1/26259
VL - 781
ER -