Interaction between a vertical turbulent jet and a thermocline
by
Ekaterina Ezhova(KTH)
→
Europe/Stockholm
122:026
122:026
Description
We investigate the dynamics of a vertical turbulent jet in an
unconfined stratified medium by means of well-resolved Large Eddy
Simulations. Vertical turbulent jets serve as models of numerous flows
both in nature and industry, including effluents from submerged
wastewater outfall systems in the ocean, convective cloud flows in the
atmosphere, pollutant discharge from industrial chimneys, subglacial
discharge from submarine glaciers. The stratification considered is
two layers of homogeneous fluids of different temperature separated by
a relatively thin layer with a temperature jump - a thermocline. This
configuration is a typical model of the upper thermocline layer in
lakes, the pycnocline in the ocean as well as thermal inversions in
the atmosphere. We consider two cases: when the thermocline thickness
is small and on the order of the jet diameter at the thermocline
entrance.
We investigate mean jet penetration, stratified turbulent entrainment,
jet oscillations and generation of internal waves and compare the
results to the theoretical models and available experimental data.
The results are applied to predict the dynamics of subglacial
discharge and wastewater effluents in summer and winter conditions.