Determination of Effective Thermal Conductivity of Stipa ichu: Numerical Shape Factor Calibration in a Reduced-Scale Hot Box

Abstract

Energy vulnerability in High-Andean dwellings necessitates the development of efficient, indigenous thermal insulation solutions. This study characterizes the thermal conductivity of Stipa Ichu fiber using a geometrically corrected, reduced-scale Hot Box method. To mitigate the metrological uncertainty inherent to low-cost devices, a hybrid experimental-numerical (CFD) methodology was implemented. Analysis using the SST k- turbulence model revealed that scale reduction induces significant multidimensional heat fluxes at the edges; consequently, a shape efficiency factor of η = 0.47 was established. Upon applying this systematic correction, an effective thermal conductivity of was determined for a compaction density of 150 kg/m3. These results validate Stipa Ichu fiber as a competitive alternative to conventional insulators, providing a viable technical solution for mitigating extreme cold conditions