EFFECT OF CORRUGATING THE COLD ORIFICE OF A VORTEX TUBE ON ITS FLOW AND ENERGY SEPARATION FEATURES

A design enhancement to the tube vortex device is suggested in this study. The proposal consists of adding fins with various sizes to the cold orifice of the device. Prior to examining the benefits of having a corrugated cold orifice geometry, a three-dimensional computational fluid dynamics model, based on the finite volume method to solve the flow and energy governing equations, is developed and validated against existing experimental data for the base geometry. The computations are performed using the commercial software, Fluent, for an air inlet pressure equal to 320 kPa. The number of fins, added to the cold air exit orifice, is ranging from 1 to 6 semicircular (0.25 mm diam) fins. The obtained results reveal that, out of all the configurations tested, the one with six semicircular fins performs the best. In such a case, the numerical predictions indicate that the corrugated cold orifice can enhance the energy separation by up to 6%. The vortex tube performance is further improved by using fins with a larger size. Indeed, increasing the semicircular inserts to the optimum diameter of 0.37 mm, results in a further improvement of the tube vortex performance to reach a staggering value of about 17%. Using fins with a diameter larger than 0.37 mm offers no additional benefits.