Pressure recovery and acceleration length of gas-solid suspension in an abrupt expansion – An Eulerian-Eulerian approach

The present study based on the Eulerian-Eulerian frame work, reports the role of inter-particle and particle–wall collisions in conjunction with pertinent parameters in an abrupt expansion pipe. The parameters that were investigated are the pressure recovery and the acceleration length. The solid loading was considered between 2 and 10, within which the roles of collisions were found to be prominent. The collisions are identified as the sole mechanism responsible for the lateral dispersion of the relatively coarse particle (400–1000 µm) into the recirculation zone. An increase in the solid loading (from 2 to 10) and the Reynolds number increases the pressure recovery and the acceleration length. On the other side, the lighter (1020 kg/m³) and relatively small sized particles (400 µm) are also responsible for the same. With an increase in the area ratio up to a critical value ≈9.97 the pressure recovery increases and then reduces.