Turbulent Mixing and Plumes

Turbulent mixing of two layers

There is a strong research thrust in the BP Institute focussing on the role of density gradients in turbulent fluid mixing, including numerical, analytical and experimental modelling. Research led by Dr Colm-cille Caulfield is aimed at understanding the route to turbulence in stratified shear flows, by detailed consideration of the different possible flow instabilities. He is also interested in improving parameterizations of irreversible mixing at high Reynolds number. Efforts are directed towards both quantifying turbulent fluxes in a range of flows, and also rigorously constraining the fluxes using upper bound theory [see e.g. Peltier and Caulfield(2003), Caulfield et al.(2004)]. There is also considerable interest in the dynamics of turbulent buoyant plumes, and their interaction with stratified environments, including models of the transient flow processes [Scase et al.(2006)] produced by changes in buoyancy.

Peltier, W.R. and Caulfield, C.P. (2003) Mixing efficiency in stratified shear flows. Ann. Rev. Fluid Mech. 35, 135-167.
◾Caulfield, C.P., Tang, W. and Plasting, S.C. (2004) Reynolds number dependence of an upper bound for the long-time-averaged buoyancy flux in plane stratified Couette flow. J. Fluid Mechanics 498, 315-332.
◾ Scase, M.M., Caulfield, C.P. and Dalziel, S.B. (2006) Boussinesq plumes and jets with decreasing source strengths in stratified environments. J. Fluid Mechanics 563, 463-472.