Drag force and heat transfer characteristics of deformable alumina droplets in compressible flows

This paper investigates the force and heat transfer characteristics of deformable alumina droplets in compressible flow. The numerical scheme couples the Navier-Stokes equations with the volume-of-fluid method, fuzzy theory, and a proportional-derivative controller. The effects of the Reynolds number, Weber number, and relative Mach number on the droplet deformation and the drag and heat transfer characteristics are studied. The results show that the fuzzy theory coupled with the proportional-derivative controller allow the droplet to reach the quasi-steady state more efficiently and robustly. The drag coefficient and Nusselt number of the droplet increase with the degree of deformation and the relative Mach number between the flow field and the droplet. The relative Mach number and the Weber number are weakly coupled with the drag coefficient and the Nusselt number. Finally, the inner two-phase flow fields of a solid rocket motor are calculated. The mechanisms whereby particle deformation influence the inner flow field of the solid rocket motor are analyzed.