2023 Volume 69 Issue 4 Pages 65-70
In processing synthetic fiber yarn, the drawing rollers draw the synthetic fiber yarn by running the rotation speed difference between multiple rollers. Meanwhile, the flow around the roller changes as the yarn runs on the roller at high speed, affecting the windage loss power. Therefore, it is effective to simulate the air flow using computational fluid dynamics (CFD) analysis to reduce both windage loss power and costs. However, when analyzing the windage loss power using CFD, if the cross section of the yarn is modeled as a circle, the contact part with the roller becomes point contact; thus, it is difficult to divide the model into meshes. Therefore, in this study, we investigated a CFD analysis model of yarn that is close to the actual phenomenon and considers the calculation cost. Consequently, we found that the model that reproduces the yarn in a strip shape to reduce the calculation cost is inappropriate as an analysis model because the flow field and the windage loss power are different. In addition, even if the cross-sectional shape of the yarn was changed from square to circular, the flow field and windage loss power remained unchanged.
