NOVEL WATER FACILITIES FOR CREATION OF COMFORTABLE URBAN MICROMETEOROLOGY

The cooling effects of artificial water facilities – fountains, waterfalls and urban canals – have not received much attention. To improve the meso-space thermal environment in an urban area, especially that during the midsummer, we propose using novel artificial water facilities to alter the temperature and humidity, so as to improve pedestrian comfort. To study this, we have carried out field measurements and wind tunnel tests, and we report the results in this paper. At first we made measurements of wind velocity, temperature and humidity around such artificial water facilities in Tennoji Park in Osaka city (a typical Japanese large city). The results showed reduced temperatures on the leeward side, and demonstrated the usefulness of water facilities in improving the thermal environment. Also, we constructed an insulated 1/400 scale wind tunnel model of the situation and measured, by means of X-type hot wire anemometer, the air currents on the wind tunnel surfaces in urban, suburban and rural terrains. We also measured, using fine-gauge T-type thermocouples, the air temperature distribution in front of and behind the model of the water facility. The results confirmed the qualitative ranges of the cooling effect provided by the actual water facilities. In particular, the cooling effect produced by a 1.0 mm diameter nozzle fountain was found to extend a distance downstream equal to ten times the height of spout.