Experiemental investigation of the interaction between slope flows and urban heat islands via image analysis techniques

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.

This paper is focused on the interaction of slope flows with urban heat islands, which are studied here by means of laboratory simulations. During the day, sunlight heats slope surfaces more than the adjacent air, resulting in a wind flow in the upslope direction: 'anabatic wind'. When the slope cools down rapidly during the night, the direction of the wind flow is reversed: 'katabatic wind'. These winds influence the strength and form of the UHIs, and its mutual interaction is studied in this paper. The combined use of thermocouples and image analysis techniques provides the simultaneous measurement of temperature and velocity components. In particular the velocity field for different time instants from the beginning of the experiments, the thickness of fluid layers interested by slope flows, the height of the plume caused by the urban heat island and its position in the anabatic and case have been determined.