Vortex tubes are an intriguing application of energy separation, featuring one inlet and two outlets on either side. A high-pressure fluid is introduced into the tube via a vortex generator, where energy separation occurs, resulting in hot fluid being released from one outlet and cold fluid from the other. Despite the interest in vortex tubes over the past few decades, the exact phenomena occurring within them remain largely unknown. This research aims to analyze the effect of varying geometries on the performance of a typical vortex tube using Ansys Fluent. Specifically, the study focuses on the hot and cold outlets to determine the most efficient design. The fluid’s temperature, pressure, and mass flow rate are analyzed using Computational Fluid Dynamics (CFD). Three different geometries were designed and analyzed by varying the radius of the hot and cold exits. The results indicate that the temperature difference between the hot and cold exits is maximized in the pointed cone geometry model compared to the truncated cone geometry. These findings demonstrate a clear correlation between geometry and vortex tube performance, suggesting that shape modifications can be used to control or vary the temperature for different applications, such as refrigeration and air conditioning systems.