ENVI-met Simulation Of Summer Microclimate In Xi’an Hanguang Street Canyon

City streets are urban residents with high frequency of outdoor living space,a good street physical environment is to improve the comfort of pedestrians in the streets of the prerequisite.In this paper,the summer microclimate was analyzed in Xi’an,and the applicability of the ENVI-met model in the climatic conditions of Xi’an area was verified by the experimental data.Compared with the measured values,the simulation results obtained by using the ENVImet finite grid can be used to make the simulation results closer to the reality.Taking ENVI-met simulation of the height of 1.5m,2.5m and 9m in the area of 80m× 80 m with optical path,we found that:(1)Of the spatial position,the exclusion of human factors,the same height of the ENVI-met analog point temperature and humidity,the road on both sides of the road than the middle of the simulation results more accurate.The measured value of humidity is affected by man-made factors such as sprinkler,and the simulation value is larger than the measured value,but less than 10% of MAPE.(2)In terms of the height of the simulation,the temperature simulation at 1.5 m is relatively more accurate and the higher the height is,the greater the simulation error is.(3)the same height,the simulation time,ENVI-met software simulation temperature during the day 12 hours of simulation results relative to 23 hours of simulation more accurate.(4)ENVI-met and can not accurately simulate the Xi’an summer 1.5m wind environment situation.(5)The ENCI-met simulation of the UTCI index is close to the measured value,indicating that ENVI-met can simulate the summer comfort distribution in Xi’an.For the different scale size ENVI-met simulation analysis,the real 440 m × 520 m and100m × 180 m,80m × 80 m three scales were simulated found:(1)ENVI-met to the temperature and humidity simulation more accurate,if the fixed network The number of grids should be reduced,the scale of the grid should be increased,and the temperature and humidity simulation results of ENVI-met will be more accurate.(2)ENVI-met wind speed simulation to be more accurate,should try to simulate the building as much as possible to increase the scale of the scale,the unit grid size does not affect the ENVI-met simulated wind speed of the main factors.In summary,the ENES-met simulation of the different height,different scales with light channel temperature and humidity of the RMES and MAPE values are within the error range,and small scale non-equidistant grid analog values compared to large scale From the grid closer to the reality value.However,the wind environment simulation results,the smaller the scale,the simulation results compared with the actual gap between the larger.