滑雪运动压缩衣材料的热传递性能建模与仿真研究OA

Ski compression garments require superior thermal insulation for low-temperature aerobic activities.Research on their heat transfer performance has significant importance with China's policy support for ice and snow sports equipment.However,existing studies focus on single-yarn knitted fabrics,while refined modeling of covered yarns with complex twisted structures remains insufficiently explored.This study established a precise geometric model for covered yarn knitted fabrics and predicted thermal insulation performance through experiments and numerical simulation. A 1+1 rib knitted fabric was designed using single covered yarn(SCY)with 900 T/m twist,comprising 30D spandex core and 40D nylon sheath.Three 20 cm×20 cm samples were prepared following ISO 11092:2014 standard.Experiments analyzed effects of humidity(0％-80％RH,five levels)and pressure(0-600 g,seven levels)on thermal conductivity. For geometric modeling,Catmull-Rom spline curves were introduced to construct the 1+1 rib loop trajectory model,replacing the traditional B-spline method.This approach offers three advantages:control points coincide with curve passing points for intuitive modeling;no inverse calculation of control points is required;and local controllability facilitates parametric adjustment.The rotation minimizing frame(RMF)double reflection algorithm was adopted to map the covered yarn cross-section along the loop trajectory in three-dimensional space,achieving fourth-order global approximation accuracy and avoiding singularity issues at locations with dramatic curvature changes. A representative volume element(RVE)model of the fabric-air system was established for finite element analysis using ANSYS Workbench.The model incorporated simplifications:core and sheath yarns were treated as homogeneous isotropic materials;one-dimensional steady-state heat transfer was analyzed along thickness direction;adiabatic boundary conditions were applied to lateral surfaces;thermal convection and radiation within pores were neglected.The heat source temperature was set at 40℃simulating skin temperature,with environmental temperature at 20℃.Mesh independence verification determined the optimal element size as 0.06 mm. Experimental results demonstrated that when humidity increased from 0％to 80％RH,moisture absorption rate only grew to 3.5％,while thermal conductivity expanded less than 1.5 times,indicating low moisture absorption and low sensitivity to humidity.In pressure experiments,when load increased from 0 g to 600 g,thermal conductivity similarly expanded less than 1.5 times,confirming good structural support during dynamic compression. Simulation results showed that the refined model achieved prediction error of approximately 7.8％,reducing error by half compared to traditional cylindrical model(15.6％).When environmental temperature varied from-5℃to 15℃,thermal conductivity change remained below 1％,maintaining constant value of 0.0 321 W/(m·K),demonstrating stable thermal insulation under temperature fluctuations typical of skiing environments.Heat rate analysis revealed that fabric-dominated regions assumed primary heat conduction function,while air layers served as thermal insulation buffer. The innovations include:Catmull-Rom spline-based loop trajectory model eliminating control point inverse calculation;RMF double reflection algorithm for covered yarn spatial mapping;and refined mesoscale yarn modeling significantly improving prediction accuracy.Limitations include exclusion of yarn hairiness effects,investigation of only 1+1 rib structure,and omission of forced convection and perspiration coupling.Future research may focus on establishing multi-physics coupled models and conducting wear trials for functional zone design of ski compression garments.