HYDRODYNAMICS ANALYSIS OF DENSITY CURRENTS

De nsity Cu rre nt is formed when a fluid with heavier den sity than the surrounding flui d fl ows down an inc lined bed. These types of flows are C0111mon in nature and can be produced by : salinity. temperatur e inhomogene itie s, or suspende d particle s of silt and clay. Driven by the den sity differenc e between inflow and clear wat er in reservoirs. density current plun ges c lear water and moves towar ds a dam. while den sity current flows on a sloping bed . The ver tical spreading due to water entrainment has an important role in determining the propagation rate in the longitudi na l dir ecti on . In this wor k. two-dimensional stea dy-state salt solutions density currents were investigated by means of experimental studies and data used in turn to verily the numeric al model. In the laboratory experimen ts. the density current enters the channel via a sluice ga te, into a lighter ambient flui d and it moves down-slope. Experiments we re performed for different conc ent rations and discharges. Verti cal velocity distributions were measured at various stations by Acoust ic Doppler Vc locimeter (ADV). I esults showed a variety of phenomena depending strongly on the entrance buoyancy flux. and Richard son number. As the discharge increases, maximum ve locity and current th ickness increase as we ll, but when concentration decreases, the current th ickness increases. In the numer ical simulation, the governing equ at ions were sol ved numerically and k-ro tu rbulence model was used fo r clo sure. Th e buoyancy term was impl emented in the numerica l mode l and its co nstant was calibrated by experiments. For verification, the height and vel ocity profi les of the dense layer were compared with the exp erimental dUL.1 and a good agreement was found .