15178

1462 دكتري

دكتري

تكنولوژي نساجي

اصفهان : دانشگاه صنعتي اصفهان

1398

سيزده، 93ص. : مصور، جدول، نمودار

محمدقانع

حسين حسني، احمد صابونچي

سعيد آجلي، محسن دوازده امامي، محسن هادي زاده

1398/07/22

كتابنامه

مهندسي نساجي

مهندسي نساجي

1398/07/22

2566036

94Abstract Heat transfer through fabrics can be influenced by several factors such as fiber thermalconductivity fiber and entrapped air volume fractions fiber material orientation and thefabric s structural pattern From previous studies it can be inferred that all the fabric sampleshave been thermally investigated while they have been in the relaxed condition with noextension However in some application the knitted fabric is in complete contact with thehuman body and takes the geometrical shape of the contact area Due to their high shape ability with the body weft knitted fabrics should also be considered to have non uniformdeformation corresponding to their contact area This leads to a non uniform extension ofthe fabric This non uniform extension would change the geometry of the fabric ultimatelyaffecting heat transfer properties In this study plain single jersey plain rib and interlock knitted structures were fabricatedusing an electronic flat knitting machine in order to investigate the temperature distribution To apply the lateral linear extension in course wise direction to the fabrics two movablejaws were designed and assembled Using this device fabrics were exposed to linear non uniform extension levels in the range of 5 to 30 A hot plate apparatus was used in orderto investigate the temperature distribution The temperature of the hot plate was set to 35 Cand the fabric was placed on the hot plate After reaching the steady state condition thethermal image of cold side was then captured by an infrared thermal camera Furthermore simulating the temperature distribution in course wise extended weft knitted fabrics byconsidering different extension levels was another aim of this study For the theoreticalevaluation meso and macro scales were considered In meso scale the fabrics corresponding geometrical unit cells were established in a finite element softwareenvironment Abaqus using Python programming In macro scale fabric was considered asa shell structure The low absolute errors of thermal conductivity 7 31 and thermal resistance 7 67 show that there was an acceptable agreement between the experimental and numericalmodeling results It has been concluded that surface temperature distribution in weft knittedfabrics induced by applying non uniform lateral extension could be properly simulated bycomputational modeling Also different extension levels of the weft knitted fabricssignificantly affected the temperature distribution in these structures In addition it could bestated that the highest thermal conductivity is related to the plain single jersey knittedstructure in comparison to the rib and interlock knitted structures Keywords heat transfer thermal conductivity weft knitted fabrics infrared thermography numerical analysis

محمدقانع

حسين حسني، احمد صابونچي

سعيد آجلي، محسن دوازده امامي، محسن هادي زاده