A Numerical and Experimental Study on the Effect of the Cone Angle of the Spindle in Murata Vortex Spinning Machine

To study the effect of the cone angle of the hollow spindle in the nozzle of Murata vortex spinning (MVS) on yarn properties, the $k‐ε$ turbulence model is employed to simulate the airflow patterns inside the different nozzles with different spindle cone angles. A set of corresponding spinning experiments is designed to verify numerical predictions. The simulation results show that some factors, such as the counter-rotating vortex pair (CVP) over the spindle, high supersonic zone in the inlet of the swirling chamber, and the distribution of wall shear stress (WSS) along the outer wall of the spindle caused by variation of the cone angle of the spindle, are significantly related to fluid flow, and consequently to MVS yarn properties. A rational cone angle (Case 2) can form an axisymmetric CVP and high WSS, which can ensure sufficient twisting of the yarn and produce high quality yarn. The experimental results, which yarn properties spun using 100% cotton, 100% polyester, and polyester 70∕cotton 30 blends with different nozzles, are well consistent with the numerical study.