Experimental And Theoretical Study On Thermal Environment Around The Fountain

With the acceleration of Chinese urbanism pace, residential clusters have become the popular dwellings for Chinese resident. It has been gradually emphasized by most people to create healthy, comfortable, and green thermal environment in a residential cluster. In planning, fountains have been the focus of the public area. However, the systematic research of the thermal environment around fountains is lack. Aiming at this absence, some researches have been carried out.First of all, because of the complexity of outdoor thermal environment, some measurement means are advanced to decrease the error. Besides, a systematic and detailed experiment is put up. Based on the analysis of the experimental data, the distribution characteristics of the thermal parameter around the fountain are presented. Then, the calculation formulas of the heat and mass transfer between a droplet and the surrounding air are derived from the analysis of a single droplet. Lagrangian Schemes are adopted and the coupling calculation model between the air and droplets is advanced on the base of PSI-CELL model. The validity and reliability of the model is verified by simulating the air-handling process in a spray chamber. Moreover, the breakup process of a straight pressure atomizer is analyzed and the thermal environment around a fountain is simulated. The result is compared with the experimental data and the validity of the model is verified. At the same time it is pointed out that the wind velocity and direction have great influence on the comparison.At last, the coupled calculation method including fountains is advanced according to the characteristic of the simulation flow and it is verified by numerical experiment. At the same time the factors that affect the thermal environment around a fountain are analyzed by numerical experiment and some guidelines are presented to optimize the design of a fountain. These guidelines include: Fountain should be planned in a square or in the middle of a main street with large density occupant, bad thermal comfort and good ventilation; Decrease the water temperature as lower as possible; Reduce the SMD of the droplets by reform the atomizer; Controlling the jet height about 3.5 m; It is not suggested to improve the thermal comfort by raising pressure, flow velocity or flux; Decrease the change of the air velocity by larging the gap of the atomizer or arranging the atomizer in-line; Planning the atomizer according the public; All the design parameter should be optimized by simulation according to the fact.The conclusion of this thesis brings a scheme for the fountain thermal environment simulation in couple calculation of a residential cluster environment and makes it possible to optimize the design of a fountain.