الفهرس 
ACKNOWLEDGMENT
Thesis outlineOnly 14 pages are availabe for public view
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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