The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocit...The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.展开更多
This paper presents a study of properties of air-jet textured threads made from high strengthpolyester filament and ordinary strength polyester filament.It includes the evaluation of tenacity,breaking elongation,modul...This paper presents a study of properties of air-jet textured threads made from high strengthpolyester filament and ordinary strength polyester filament.It includes the evaluation of tenacity,breaking elongation,modulus,specific work,evenness,abrasion resistance,hook strength,knotstrength and other mechanical properties relating to sewing.The polyester air-jet texturing sewingthread has special structure and appearance and possesses better properties of evenness,goodabrasion resistance,fatigue property,high hook and knot strength.展开更多
Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is sim...Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is simulated numerically. The negative pressure effect is much bigger at the top of low-fiber hollow spindle than that in Murata No.861,which is more conducive for single fiber to get into the channel of hollow spindle. The tangential velocity in 0-3 mm at the top of hollow spindle increases and the fluctuation of radial velocity is much stronger,which enhance the wrapping effect. In the addition,the distribution of axial velocity remains the same.展开更多
This paper deals with the structure of air-jet textured yarn(ATY),especilly its core structurein dedail.It is described that overfeed of supply yarn does influence the ATY structure.Then thebending rigidity of ATY has...This paper deals with the structure of air-jet textured yarn(ATY),especilly its core structurein dedail.It is described that overfeed of supply yarn does influence the ATY structure.Then thebending rigidity of ATY has been measured and analyzed.The results shows that various supplyyarns affect the core structure and bending rigidity of ATY.展开更多
For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get...For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.展开更多
The Absorption and permeability of air-jet textured glass fiber yarn and its fabric and bonded tenacity of the fabric have been studied in relation to the main parameters, air supplied pressure and overfeed ratio.It h...The Absorption and permeability of air-jet textured glass fiber yarn and its fabric and bonded tenacity of the fabric have been studied in relation to the main parameters, air supplied pressure and overfeed ratio.It has been observed that increasing the level of main parameters improves the coated ratio of the textured yarn and its fabric as well as the bonded tenacity of the fabric made of textured yarn. Comparison of absorption or permeability between textured and supplied yarns, and comparison of absorption or permeability and bonded tenacity between the two kinds of fabrics have been elucidated.展开更多
Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (v...Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control.展开更多
Solenoid valve is one of the executive parts of weft insertion control system. According to the response characteristics of the solenoid valve, an improved design becomes a necessity. Firstly, the numerical model was ...Solenoid valve is one of the executive parts of weft insertion control system. According to the response characteristics of the solenoid valve, an improved design becomes a necessity. Firstly, the numerical model was established after analyzing the solenoid valve during its start-up and shut-down. Comparing the simulation data with the practical data, it is verified that the numerical simulation model has a high feasibility. Secondly, excitation voltage and spring pre-compression were adjusted respectively, and the response rules after adjusting were investigated. The research of the study shows: the response time tends to be inverse proportional to the excitation voltage during start-up, and it becomes a constant value with the increase of the excitation voltage; the response time is proportional to the spring pre-compression when the solenoid valve starts up, it is inverse proportional to spring pre-compression when the solenoid valve shuts down. And the total response time is a constant value with the increase of the spring pre-compression. Therefore, the value of the excitation voltage and the spring pre-compression should be selected when the curve is becoming flatten. The results of the research can provide the reference to the further development of the solenoid valve.展开更多
文摘The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.
文摘This paper presents a study of properties of air-jet textured threads made from high strengthpolyester filament and ordinary strength polyester filament.It includes the evaluation of tenacity,breaking elongation,modulus,specific work,evenness,abrasion resistance,hook strength,knotstrength and other mechanical properties relating to sewing.The polyester air-jet texturing sewingthread has special structure and appearance and possesses better properties of evenness,goodabrasion resistance,fatigue property,high hook and knot strength.
基金Program for Changjiang Scholars and Innovative Research Team in University,China(No.IRT1220)Shanghai Natural Science Foundation,China(No.13ZR1400900)Keygrant Project of Chinese Ministry of Education(No.113027A)
文摘Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is simulated numerically. The negative pressure effect is much bigger at the top of low-fiber hollow spindle than that in Murata No.861,which is more conducive for single fiber to get into the channel of hollow spindle. The tangential velocity in 0-3 mm at the top of hollow spindle increases and the fluctuation of radial velocity is much stronger,which enhance the wrapping effect. In the addition,the distribution of axial velocity remains the same.
文摘This paper deals with the structure of air-jet textured yarn(ATY),especilly its core structurein dedail.It is described that overfeed of supply yarn does influence the ATY structure.Then thebending rigidity of ATY has been measured and analyzed.The results shows that various supplyyarns affect the core structure and bending rigidity of ATY.
文摘For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.
文摘The Absorption and permeability of air-jet textured glass fiber yarn and its fabric and bonded tenacity of the fabric have been studied in relation to the main parameters, air supplied pressure and overfeed ratio.It has been observed that increasing the level of main parameters improves the coated ratio of the textured yarn and its fabric as well as the bonded tenacity of the fabric made of textured yarn. Comparison of absorption or permeability between textured and supplied yarns, and comparison of absorption or permeability and bonded tenacity between the two kinds of fabrics have been elucidated.
基金Support from Polish National Science Centre grant number N502 265837 as well as 6 EU FP UFAST and AITEB-2 projects
文摘Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control.
基金supported by the National Natural Science Foundation of China(No.51006090)
文摘Solenoid valve is one of the executive parts of weft insertion control system. According to the response characteristics of the solenoid valve, an improved design becomes a necessity. Firstly, the numerical model was established after analyzing the solenoid valve during its start-up and shut-down. Comparing the simulation data with the practical data, it is verified that the numerical simulation model has a high feasibility. Secondly, excitation voltage and spring pre-compression were adjusted respectively, and the response rules after adjusting were investigated. The research of the study shows: the response time tends to be inverse proportional to the excitation voltage during start-up, and it becomes a constant value with the increase of the excitation voltage; the response time is proportional to the spring pre-compression when the solenoid valve starts up, it is inverse proportional to spring pre-compression when the solenoid valve shuts down. And the total response time is a constant value with the increase of the spring pre-compression. Therefore, the value of the excitation voltage and the spring pre-compression should be selected when the curve is becoming flatten. The results of the research can provide the reference to the further development of the solenoid valve.
