NUMERICAL SIMULATION OF TURBULENT FLOW AND WALL MASS TRANSFER IN A RECTANGULAR CHANNEL ROUGHENED BY V-SHAPED GROOVES

A numerical study in a rectangular channel is performed to investigate the effect of roughness of a transverse V-shaped groove on flow and wall mass transfer characteristics. The study is completed by four rough walls with different groove sizes, and the Reynolds number spans from 10(3) to 10(5). The flow and concentration fields are obtained using a validated low Reynolds number k-epsilon turbulence model. The influences of Reynolds number, groove depth, and groove pitch on near-wall flow and wall mass transfer are discussed. The mass transfer boundary layer developments and local mass transfer coefficient distributions over different walls are presented. As the grooves become denser and shallower, the more augmentation of wall mass transfer rate is observed. However, increasing Reynolds number weakens the enhancement effect. The averaged Sherwood number is correlated as a function of Reynolds number and groove geometric parameters.