The air-jet loom is widely used in the textile industry and the main nozzle is one of its key components. In this paper, the influence of some parameters, including the input air pressure and the structure of nozzle core and its internal diameter, on the internal flow field of the main nozzle is analyzed. Then the optimized structure of the main nozzle is proposed from the perspective of fluid dynamics. In the present simulations, the realizable k - ɛ model is applied to model the internal flow field of the main nozzle. The results show that the velocity in the annular throat reaches supersonic. Moreover, the pressure at the end of the nozzle core is the lowest in the main nozzle. It is also shown that the input air pressure has little effect on the axis velocity in Zone B, but on the other hand, has a great influence on the near-wall velocity field and the axis velocity in Zone C. In addition, an optimized structure of the nozzle core is proposed in this paper. It is found that with the proposed structure, the velocity boundary layer near the wall of Zone B in the accelerating tube can be well improved, and rapid diffusion of airflow in this area can be avoided. These help increase the moving speed of the weft yarn. Last but not least, we also show that decreasing of the internal diameter of the nozzle core improves the axis velocity of the weft accelerating tube. However, it brings a stronger turbulence at the same time.
[1]
Atsushi Okajima,et al.
Flow Characteristics of the Main Nozzle in an Air-Jet Loom
,
1994
.
[2]
Giuliana Mattiazzo,et al.
Numerical Model of an Air-jet Loom Main Nozzle for Drag Forces Evaluation
,
2009
.
[3]
Shintani Ryuji,et al.
Air Flow through a Weft Passage of Profile Reed in Air Jet Looms
,
2002
.
[4]
Shuan Jun Song,et al.
Synthetic Flow-Field Analysis of Main and Auxiliary Nozzles in Air-Jet Looms
,
2011
.
[5]
S. D. Kim,et al.
A Numerical Analysis of Transonic/Supersonic Flows in the Axisymmetric Main Nozzle of an Air-Jet Loom
,
2001
.
[6]
S. Adanur,et al.
Analysis of Air Flow in Air-Jet Filling Insertion
,
1991
.