基于胸部形态的文胸推荐系统实现与应用
2018-09-10李婧鲁虹张欢
李婧 鲁虹 张欢
摘要: 为了快速设计出透气性符合实际要求的织物,并研究气流在织物内部的运动和压力、压强的变化规律,文章提出了利用ANSYS CFX对织物透气性进行数值计算的方法。首先建立织物模型,再在此基础上对织物模型进行处理,然后对不同压强下的织物进行数值计算。结果表明:气流主要通过织物孔隙和纱线之间的间隙,并且通过孔隙时由于迁移加速度的存在速度会增加;通过空隙时在纱线表面会存在很大的剪切力和压力;模拟值与实验值进行比较得到的模拟误差小于16%,所以得到的模型可以反映织物的实际特征。造成误差的主要原因包括:测试偶然误差、模型参数误差、边界条件与测试条件之间的差别。
关键词: 织物模型;布尔运算;ANSYS;网格;有限元
中图分类号: TS101.1
文献标志码: A
文章编号: 10017003(2018)09005106
引用页码:091108
Numerical calculation of fabric air permeability based on ANSYS CFX
DAI Wenjie, QIU Hua, YANG Enhui, WANG Ning, YAN Zhenglin
(Key Laboratory of EcoTextiles, Ministry of Education, Jiangnan University, Wuxi 214122, China)
Abstract: In order to rapidly design fabrics whose air permeability meets the actual requirements, and study the changing rules of movement, pressure and pressure intensity of air flow inside the fabric, a method was proposed to numerically calculate the air permeability of fabric by using ANSYS CFX. Firstly, the fabric model was established and processed. Then, the fabrics are numerically calculated under different pressure intensity. The results show that the airflow mainly passed through the gap between the fabric pores and the yarn, and the speed would increases due to the migration acceleration when passing through the pores. There is large shear force and pressure on the yarn surface when passing through the voids. The simulation error obtained by comparing the simulation value with the experimental values was less than 16%, so the model can reflect the actual characteristics of the fabric. The main causes of errors include: accidental errors of test, model parameter errors, and differences between boundary conditions and test conditions.
Key words: fabric model; Boolean operation; ANSYS; grid; finite element
織物的透气性表示气流在一定压差下通过织物后气流的速度,与织物的保暖性和舒适性密切相关;也会影响空气过滤材料的过滤效能;影响到衣服与空气和水之间能量传递,从而影响洗涤和晾晒的效率。所以,研究气体或者液体在织物内的流动特征具有重要的意义。
姚穆等[12]研究得出织物内部存在较多孔隙,孔隙主要包括:纱线之间、纤维之间,以及多层织物之间,其中纱线之间和层与层之间的孔隙对织物透气性影响最大。S.Jaganathan等[34]利用2D的图像中像素不同生成3D的纤维束模型,以及为了提高模拟的准确性应该添加周期性网格,并假设气流在纤维束内进行层流流动,得到气流在纤维束内的流动状态。……
