Experimental and CFD Assessment of Hotspot Heat Propagation in Stored Barley

Localised heating in stored barley can remain undetected when temperature measurements are spatially sparse.This study combines a small-scale experiment and computational fluid dynamics to assess heat propagation from a controlled hotspot and its implications for temperature monitoring.A transient three-dimensional porous-medium model with coupled heat and moisture transfer was developed in Ansys Fluent and compared with measurements from a geometrically similar 1:20 silo tube testbench.A heated copper sphere, 60 mm in diameter, represented a localised thermal source; biological heat generation was not modelled explicitly.The reported average standard error was 0.58°C, the maximum standard error was 0.96°C, and the maximum absolute prediction error was 1.26°C.Two prescribed hotspot temperatures, 38°C and 45°C, were investigated over 14 days.The corresponding 1°C temperaturerise contours travelled 456 mm and 531 mm, respectively, with propagation slowing over time.The higher source temperature increased the reported 14-day distance by 75 mm, or approximately 16%.These results illustrate the limited spatial reach of a local temperature disturbance under the investigated conditions and support assessment of sensor location when interpreting silo temperature records.However, a 1 °C contour does not establish a reliable detection radius, particularly given the stated ±1°C thermocouple accuracy.Numerical sensitivity, measurement uncertainty and full-scale boundary effects require further assessment before the results can define industrial sensor spacing or detection times.