Numerical Simulation And Analysis Of Complete Condensing Spinning System Using Fluent Software

Complete condensing spinning system (CCSS) is a new kind of compact spinning systemwith negative pressure roller, and it was jointly invented by Jiangnan University andChangzhou Henji Textile Machinery Co, Ltd. Because of the unique structure of narrow slotroller, CCSS has different condensing effect and airflow motion regular. At present, there islittle research on pressure airflow distribution and air motion as well as the flow fielddistribution in condensing area when different process parameters and components are used.All this should be discussed systematically. Fluent is one kind of software which is usuallyused to research physical problems such as fluid flow phenomenon by the way of numericalcalculation and image display in computer. It can greatly reduce the loss of manpower andmaterial resources when Fluent is used to study fluid flow problems. Currently there are stillno scholars to study the condensing zone of CCSS based on Fluent. For this, this paper adoptsthe method of computational fluid dynamics to discuss the airflow of condensing zone basedon Fluent so as to lay a theoretical foundation for the actual system optimization design.Firstly, three-dimensional physical model and mathematical model of condensing zone ofCCSS are built, and the numerical simulations of the flow distribution are given by usingFluent software. To reflect the whole condensing areas flow field, velocity distribution curvesof three different positions along the direction of fiber sliver are drawn, and the velocitydistribution of the arc trajectory above narrow slot roller is plotted. Secondly, based on this,corresponding simulation results of airflow distributions in condensing area with threedifferent air suction slots are obtained. And their influence on the condensing effect isanalyzed respectively. Thirdly, airflow distributions in condensing area with no airflow guidedevice and three different types of airflow guide device in CCSS are simulated as well, andthe influence of airflow guide device on condensing effect and yarn qualities are discussed.The results of the study are as follows:The airflow distributions on different height from narrow slot roller are similar, but thevelocity values are different, and it achieve maximum when h=0.5mm. CCSS has goodcondensing effect in whole condensing zone because of the proper distribution of velocitycomponent on Y-axis and Z-axis; the shape of the suction slot has a great impact on theairflow distribution. The long and short oblique grooves have better condensing effect in thewhole condensing area, but they may have negative effect on spun yarn evenness. The straightgroove may spread the sliver again in the median space; Airflow guide device has a greatimpact on the airflow distribution in condensing zone. The condensing effect of CCSS isweak and there is much hairiness on the yarn when it was not equipped with airflow guidedevice. However, the yarn evenness is better in this situation. The condensing effect isobviously stronger and its yarn hairiness is less when it is equipped with airflow guide device,but its CV of evenness is bigger. Among the three kinds of airflow guide device, the type Chas the best condensing effect and its yarn hairiness is the minimum.