Numerical simulation of a solar wood dryer

Abstract

This article addresses a comprehensive analysis of the fluid dynamics in an Oxford-type solarkiln for wood drying. The work focused on a solar dryer located in Tacuarembo (Uruguay),with an approach that is both experimental and numerical. A detailed analysis of theinternal fluid dynamics in this type of kiln is essential to improve drying efficiency and avoidheterogeneous drying, which can lead to defects such as wood warping and reduced mech-anical properties. It is well known and widely analyzed in the literature that ensuring homo-geneous flow in the wood lumber is crucial to avoid these problems. To address thesechallenges, an experimental analysis was performed to characterize the flow behavior insidethe kiln. Additionally, numerical simulations were performed with OpenFOAM, incorporatinga fan model based on data provided by the manufacturer. A rigorous mesh convergencestudy validated the numerical results with experimental measurements. The simulationsrevealed key flow characteristics, including stagnation zones, recirculation areas, flow diver-sion around the stack, and flow heterogeneity within the stack. Potential modifications tothe furnace design are proposed to improve flow uniformity and minimize air diversion,leading to improved dryer performance.