Numerical study of the effect of geometric parameters on the internal flow of a pressure nozzle for dustfall

Abstract

Using Computational Fluid Dynamics (CFD) simulations, this paper first investigated main structural parameters effecting the internal flow of the pressure nozzle (i.e., convergent angleα1, outlet diameterD2, swirl angle α2, and flow area A). A comparative study of the outlet velocity and cross-section velocity vector were performed. Results indicate that with the increase inα1, the axial velocity of the outlet decreased slightly, the tangential velocity increased, and the swirl degree of the outlet increased gradually. With the increase inD2, the axial velocity decreased. The tangential velocity first increased and subsequently decreased slowly, similar to the swirl degree of the outlet. With the increase in α2, the axial velocity decreased similarly, and the tangential velocity and swirl degree of the outlet increased. With the increase in A, the axial velocity increased, and the tangential velocity and swirl degree of the outlet decreased gradually. The swirl angle α2 affected the swirl number S the most, the value of S increased above 50% significantly when α2 from 25° to 35°. The outlet diameter D2 affected the outlet velocity V most. The tangential velocity increased almost 30%-50% significantly when D2was changed from 1 to 1.5 mm. They are the most crucial structure parameters in dustfall nozzle geometric optimization.