Experimental and 3D CFD analysis on optimization of geometrical parameters of parallel vortex tube cyclone separator

The air separators or vortex tubes are widely used in rotor craft engines. The air separators are used to provide an appropriate air stream (clean air) to helicopter engines. Vortex tubes are normally categorized according to direction of exiting flows. This article focuses on some results (both experimental and numerical) into the optimization and analysis of the separation performance/efficiency and fluid patterns in parallel vortex tubes (PVTs) as one of the most interesting types of air separators. Regarding the Ranque-Hilsch vortex tubes, the separated fluids (gas or liquid) or hot and cold streams (dirty and clean) leave the vortex tube at two different sides, in the case of parallel vortex tubes, both exhausts are located in one side (control valve position). In this research the effects of a new nozzle position (parallel injector), throttle orifice diameter (6.5-9.5 mm) and length of parallel main tube (180-220 mm) on the quality of the separation process in the Ranque-Hilsch and the parallel air separator (PVT) are analyzed. The results show that the parallel vortex tube with optimized length, injection angle and orifice diameter provides 66.08% (14.83 K) and 58.61% (13.88 K) higher thermal separation performance as compared to the initial parallel vortex tube.