A modified two-fluid model of turbid density current based on effective drag coefficient

Abstract

The two phase numerical models applied for resolving turbid density current have developed recently, while the inter phase forces of the usual two-fluid model only include the viscous drag. Based on the analysis of the motion and forces of a small single particle (d p =0.01mm∼0.09mm) in the uniform flow field obtained from the dynamic equation, it was found that the proportion of the Basset force was 7.3%∼25.6%. Therefore it was necessary to include the Basset force in the usual two-fluid model when it was applied to simulate the turbid density current containing fine sediment. Here, the effective drag including the Basset force and the viscous drag was proposed, and the formulas of the effective drag coefficient C T was obtained which contained Reynolds number and Archimedes number. Then, the modified two-fluid model was applied to simulate the turbid density current in a glass tank. It showed that the maximum head thickness got from the modified model were more close to the experiment.