Effects of a porous manifold on thermal stratification in a liquid storagetank

A numerical model for a porous manifold has been developed to study its eff ects on thermal stratification in a typical storage tank. The tank consider ed has a capacity of 300 1 and a height-to-diameter ratio of 2. The numeric al model employs a transient stream function-vorticity formulation to predi ct the development of flow and temperature fields in a charging process. Th e Reynolds number of the inlet flow is fixed at 200 and a wide range of the Richardson number (0.01 less than or equal to Ri less than or equal to 100 ) is considered. Other parameters considered include the Biot number (i.e. heat loss from the tank), the Darcy number (permeability of the porous mani fold), the location of baffle, and the thickness of the porous tube. The re sults show that all these factors should be taken into account for a better design of a thermal storage tank. In addition, the results provide an enve lope for these design parameters. (C) 2001 Elsevier Science Ltd. All rights reserved.