Nigel Kaye

Time-dependent flows in an emptying filling box

We examine the transient buoyancy-driven flow in a ventilated filling box that is subject to a continuous supply of buoyancy. A rectangular box is considered and the buoyancy input is represented as a turbulent plume, or as multiple non-interacting plumes, rising from the floor. Openings in the base and top of the box link the interior environment with a quiescent exterior environment of constant and uniform density. A theoretical model is developed to predict, as functions of time, the density stratification and the volume flow rate through the openings leading to the steady state. Comparisons are made with the results of small-scale analogue laboratory experiments in which saline solutions and fresh water are used to create density differences. Two characteristic timescales are identified: the filling box time (

Coalescing axisymmetric turbulent plumes

T_f

Turbulent Plumes in Stratified Environments : A Review of Recent Work

), proportional to the time taken for fluid from a plume to fill a closed box; and the draining box time (

Overturning in a filling box

T_d

The role of diffusion on the interface thickness in a ventilated filling box.

), proportional to the time taken for a ventilated box to drain of buoyant fluid. The timescale for the flow to reach the steady state depends on these two timescales, which are functions of the box height

Investigation of Flow through Orifices in Riser Pipes

H

Hydrologic Characterization of Undrained Porous Pavements

and cross-sectional area

Interacting Turbulent Plumes in a Naturally Ventilated Enclosure

S

Shear-driven flushing of dense fluid from a canyon

, the ‘effective’ opening area

Hydraulic Performance of Aggregate Beds with Perforated Pipe Underdrains Flowing Full

A^*