Investigation on Flow Field Characteristics by Drag Reducing Agent Additives in a Stirred Vessel

Abstract

In this paper, experimental investigation on two oil-soluble drag-reducing agents (DRAs) were carried out in stirred vessel by standard six-blade Rushton, based on the application of particle image velocimeter (PIV). Two DRAs (1# and 2#) with different concentrations from 3 ppm to 50 ppm were added into diesel, respectively, and speed of impeller speed was set 400 rpm. Flow field characteristics including turbulence intensity, turbulent kinetic energy (TKE), and energy dissipation rate (EDR) influenced by those additives in stirred vessel were studied. It was found that inhibition effect of turbulence intensity of the two DRAs is not obvious with concentration below 10 ppm. However, when concentration is above 10 ppm, turbulence inhibition effect becomes more obvious. Under low concentration, 1# has better turbulence inhibition effect in the area near impeller, while 2# has better turbulence inhibition effect under high concentration. When the two DRAs are under the same concentration of 50 ppm, turbulent flow energy and energy dissipation rate are obviously reduced.

VMD analysis of pulsating flow pressure signal of oil with different particle concentration

“…For example, Dritselis and Vlachos 4 pointed out that copper particles in the fluid would weaken the strength of coherent structures of turbulence and inhibit the development of these structures. Qi et al 5 applied particle image velocimeters (PIV) to the flow field characteristics of two oils in the stirring vessel-soluble drag reducing agent(DRA) found that these additives have an effect on turbulence strength, turbulence kinetic energy (TKE) and energy dissipation rate (EDR) in the stirring vessel. The inhibition of turbulence intensity by DRA at concentrations below 10 ppm is not significant.…”