Numerical Simulations of Yarn Unwinding from Packages

Praček, Stanislav; Franci, Sluga

doi:10.3390/mca15050846

Cited by 2 publications

(4 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the operator expression (4) is applied to the velocity equation (3), we obtain the relation between the accelerations a and a ′ 10,12,13 …”

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

“…Assuming a negligibly small yarn cross-section and ideal elasticity, one may derive the following equation of motion in an inertial reference frame 7,10 …”

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

“…In a rotating reference frame, equation (8) takes a form similar to that of equation (7) 10

where r ( s , t ) is the radius vector pointing to an infinitesimal section of the yarn, which at time t is located at the arc-length s away from the origin, ρ is the linear yarn mass density, that is, the mass of the yarn per unit length, which is not necessarily constant in an extensible yarn. The mechanical tension is denoted by T ( s , t ), and t ( s , t ) is the tangential vector to the yarn at the given point; it equals the partial derivative of the radius vector r with respect to the arc-length s , that is, t = ∂ r /∂ s .…”

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

“…Building on this foundation, we have simplified the problem even further. Praček and Sluga 10 and Batra and Fraser 11 showed the origin of the fictitious forces in the equations of motion. In this paper we show how these forces enter the equation of motion for yarn in a rotating reference frame.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Fictitious forces in yarn during unwinding from packages

Praček

Pušnik

2016

Textile Research Journal

Self Cite

View full text Add to dashboard Cite

In this paper we discuss the general equation of motion for yarn in a rotating coordinate system. This equation is often used to describe the motion of yarn that is unwinding from packages. The rotating coordinate system is non-inertial and the equation of motion therefore contains fictitious forces. We comment on the physical significance of fictitious forces that appear in a non-inertial frame and we devote particular attention to a less known Euler force that only appears in non-uniformly rotating frames. We show that this force should be taken into account when the unwinding point is near the edges of the package, when the quasi-stationary approximation is not valid because the angular velocity is changing with time. The additional force has an influence on the yarn dynamics in this transient regime, where the movement of yarn becomes complex and can lead to yarn slipping and even breaking.

show abstract

“…If the operator expression (4) is applied to the velocity equation (3), we obtain the relation between the accelerations a and a ′ 10,12,13 …”

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

“…Assuming a negligibly small yarn cross-section and ideal elasticity, one may derive the following equation of motion in an inertial reference frame 7,10 …”

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

“…In a rotating reference frame, equation (8) takes a form similar to that of equation (7) 10

Section: Fictitious Forces In Rotating Reference Frames With Non-consmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Fictitious forces in yarn during unwinding from packages

Praček

Pušnik

2016

Textile Research Journal

Self Cite

View full text Add to dashboard Cite

show abstract

Analysis of the Twisting Tension in the Direct-Twisting Machine and the Fitting Model Based on the Experimental Data

Shunqi

Zhang

et al. 2022

Applied Sciences

View full text Add to dashboard Cite

The tension of the balloon yarn in the direct-twisting machine affects the yarn breakage and balloon shape, which in turn affects the energy consumption and yarn productivity of the direct-twisting machine. At present, research on the balloon tension of an industrial yarn direct-twisting machine is very rare, both in China and abroad. In this regard, this paper establishes a theoretical model for balloon yarn tension during the yarn twisting process of an industrial yarn direct-twisting machine based on yarn balloon kinematics. The experiment of the yarn balloon tension of the direct-twisting machine under different yarn fineness and different spindle angular speed is carried out. The influence of the angular speed of the spindle, the yarn fineness, and other factors on the tension of the balloon yarn in the direct-twisting machine is investigated. By using mathematical statistics and regression analysis methods, the fitting equations of the yarn balloon tension of the direct-twisting machine are established. The research results show that the relationship between the balloon yarn tension of the direct-twisting machine, the angular velocity of the spindle, and the yarn fineness can be fitted by a quadratic polynomial. The predicted value of balloon yarn tension based on the fitted equation has a small relative error compared to the measured value, and the prediction result is more reliable and accurate. This paper contributes specifically by adding to the understanding of how to model the yarn tension for the specific machine and the range of the test. It also contributes to the generical methodology on how to develop such a model.

show abstract

Numerical Simulations of Yarn Unwinding from Packages

Cited by 2 publications

References 3 publications

Fictitious forces in yarn during unwinding from packages

Fictitious forces in yarn during unwinding from packages

Analysis of the Twisting Tension in the Direct-Twisting Machine and the Fitting Model Based on the Experimental Data

Contact Info

Product

Resources

About