الفهرس | Only 14 pages are availabe for public view |
Abstract In this study, experimental and numerical work is done to investigate the performance of the single and multiple vortex tubes. A modification to vortex tube chamber design with ether cylindrical or conical shape is introduced and assessed through this research. For the cylindrical vortex chambers, three different diameters are suggested, 20, 16 and 12 mms, with three different axial lengths, 20, 15 and 10 mms. While a six conical vortex chambers are fabricated with only two different diameters, 20 and 16 mms reduced to 12 mm through the same three axial different lengths as in the cylindrical vortex chambers. The experiments are performed under inlet air pressure supply ranged from 0.5 to 3 bar with 0.5 bar increment. A performance comparison between the new design and the conventional inlet nozzle vortex tube is performed experimentally and numerically to assess the new design characteristics. The performance of multiple vortex tubes is obtained through testing different numbers of commercial vortex tubes in parallel connection. The experimental results show that the vortex tubes with modified cylindrical vortex chamber have a better performance than the conventional one under all operating conditions. Moreover, the vortex tube performance is greatly affected by the geometrical parameters of the vortex chamber. The increasing vortex chamber length enhances the vortex tube performance by getting a large cold and hot temperature difference. The enhancement increases by increasing the vortex chamber length to vortex chamber diameter ratio (L/D) up to 0.75, and then the enhancement decays. The vortex chamber modification improve isentropic efficiency, cooling efficiency and heating efficiency than the conventional vortex tube design, but the degree of improvement in cooling efficiency is larger than that in heating efficiency. The vortex chamber of L/D=0.75 exhibits the highest |