APPLICATION OF INFRARED THERMOGRAPHY FOR PEDESTRIAN WIND EVALUATION

This paper describes a new experimental method using infrared thermogr aphy for the evaluation of wind impact at pedestrian level. The develo ped measurement system consists of a heated plate on which building mo dels stand, an infrared video camera for detecting the surface tempera ture distributions on the heated plate, and a microcomputer for image processing and presentation. Since the heat loss from the heated plate can be related to air flow speeds by the principle of heat convection , the surface temperature pattern is used as an indicator of the wind impact at the pedestrian level. Results have been derived from thermal images around various buildings both on selected points and over enti re affected areas that are quantified by the reduced temperature and t he overall impact, respectively. The paper presents details of the exp erimental setup, operational principles, calibration results, applicat ion examples, and further thoughts on this technique. At the current s tage, the infrared technique is capable of visualizing surface how fie lds through color images, quantifying windy zones in terms of temperat ure variation, and evaluating the overall wind impact by further calcu lation.