A Ranque-Hilsch vortex tube is a mechanical device in absence of any portable part or work input and significantly separates the inlet gas stream into hot and cold gas which provides a variety of applications. Current research consists a three-dimensional numerical model at steady state condition using installed fins on cold tube. Six different geometry were chosen for fins including triangle, square, rectangle, circle, parallelogram and trapezium. The outcome data of the research then is verified with compare to prior experiment results brought in literature. This book surveys the influence of different fin shapes on critical performance parameters of cold temperature difference, hot temperature difference, isentropic efficiency and COP numerically. The modeling results indicate that the parallelogram and rectangular fins have the highest and lowest cold temperature difference, isentropic efficiency and COP, respectively.