Numerical investigation of tangential injection angle effects on thermal separation performance in vortex tubes

Abstract This study investigates a counter-flow vortex tube using air as the working fluid. A numerical model was established to systematically examine the influence of tangential injection angle in the vortex chamber nozzle on thermal separation performance. The results demonstrate that significant temperature separation occurs within the tangential injection angle range of 0° - 50°. The energy separation efficiency exhibits a non-monotonic trend with increasing injection angle, initially rising and then declining, reaching its peak at a 30° tangential angle where the cold flow ratio attains its minimum value. Rational adjustment of the tangential injection angle enables effective regulation of cold-end temperature, thereby optimizing the energy separation performance of the vortex tube. These findings provide a crucial theoretical foundation for structural design and performance optimization of vortex tubes.