A scale-model experiment of surface temperature characteristics using an infrared radiation camera

Abstract

An outdoor measurement was performed during fine weather with a scale-model array of cubical obstacles (size 100mm, 25% packing density, lattice-type square layout) that represent an idealized urban tissue. Surface temperature was recorded with high-frequency (10Hz) infrared camera, along with wind speed and solar radiation. Complementarily, air temperature was also measured at three heights in the near-wall region of a block surface using fine-wire thermocouples. Results showed the similarity of distribution between surface temperature and scalar transfer coefficient. We also found that 10s averaging period may be appropriate for the analysis of surface temperature fluctuation affected by turbulent airflow. In the near-wall region under particularly calm wind condition, air temperature fluctuation caused by a hot plume arising from the warmed surface was observed. The method presented in this study seems to be a promising tool to analyze surface temperature characteristics of scale-models in urban climate studies.