本文關(guān)鍵詞：鋪面參數(shù)對近地?zé)岘h(huán)境的影響研究　出處：《重慶交通大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 計算流體動力學(xué) 不同下墊面類型 材料特性 近地氣溫

【摘要】：城市化進(jìn)程中,天然地表被人造鋪面取代后,造成近地大氣熱環(huán)境變化,形成城市熱島效應(yīng)。為了分析路面形式、鋪面材料參數(shù)對近地?zé)岘h(huán)境的影響規(guī)律,首先,本文將路面-近地大氣視為一個相互作用的系統(tǒng),進(jìn)行三維數(shù)值建模,應(yīng)用計算流體動力學(xué)(CFD)的非穩(wěn)態(tài)方法求解控制方程。其次,通過實(shí)測數(shù)據(jù)分析了不同下墊面類型、太陽輻射強(qiáng)度等因素對城市近地?zé)岘h(huán)境的影響,并對路-氣響應(yīng)模型的數(shù)值計算結(jié)果進(jìn)行了有效性驗(yàn)證。最后,利用路-氣響應(yīng)模型計算并分析了太陽輻射、道路材料特性對建筑群內(nèi)近地?zé)岘h(huán)境的影響,并總結(jié)了不同鋪面上方空氣溫度分布規(guī)律。主要研究結(jié)論如下:①提出了采用正反2個太陽總輻射表組成的雙表測試鋪面表面反射率的試驗(yàn)方法和以當(dāng)?shù)卣嫣枙r11:00~13:00的平均值作為鋪面反射率計算方法。②基于計算流體動力學(xué)(CFD)方法,考慮太陽短波輻射、熱傳導(dǎo)、對流換熱和鋪面-大氣之間的有效長波輻射,建立了路-氣響應(yīng)的三維有限元分析模型,通過實(shí)測數(shù)據(jù)對路-氣響應(yīng)的三維有限元結(jié)果檢驗(yàn)表明,該計算模型對白天時段溫度數(shù)值的模擬具有較好的精度,但對夜晚時段,其模擬精度還需進(jìn)一步優(yōu)化。③晴朗白天時分,草地鋪面上方0~60cm高度范圍內(nèi),氣溫值波動較大。對于硬質(zhì)不透水性鋪面和水泥鋪面來說,該高度范圍值分別為0~50cm,0~100cm。針對大多數(shù)不透水性鋪面,白天時段其路表上方氣溫分布形式可分為三種類型,分別為:日出時分型、日間時分型、傍晚時分型。④針對重慶市解放碑商圈來說,瀝青材料為下墊面的路表溫度場中高溫區(qū)的分布面積明顯多于以水泥和硬質(zhì)不透水性鋪面為下墊面時的高溫區(qū)分布面積,且在溫度值上也相對較高。由此可見,瀝青路面因其較水泥、硬質(zhì)不透水性鋪面有較高的吸收率、比熱,不適宜將其作為小區(qū)或商圈步行街的下墊面。⑤對于商圈步行道路表溫度及上方氣溫而言,其區(qū)域內(nèi)平均的溫度數(shù)值隨著反射率、發(fā)射率、導(dǎo)熱系數(shù)、比熱等參數(shù)的增大而減小,但溫度減小幅度值隨著高度的增加逐漸降低。具體結(jié)果:晴朗正午時分,鋪面反射率每增加0.1,路表平均溫度下降0.6℃,路表上方平均氣溫下降0.16℃~0.45℃。進(jìn)一步分析發(fā)現(xiàn),反射率變化對1.2m高度以下范圍的氣溫值影響顯著,但是對于較高處(≥1.2m高度)的氣溫值,其改善效果較小。綜合分析各材料參數(shù)對近地氣溫的影響可得,通過優(yōu)化材料的反射率和比熱兩個參數(shù),可改善城市熱島效應(yīng)。
[Abstract]:In the process of urbanization, the natural surface is replaced by artificial pavement, which results in the change of atmospheric thermal environment and the formation of urban heat island effect. In order to analyze the pavement form, the influence of pavement material parameters on the near-geothermal environment is studied. Firstly, the road-near-Earth atmosphere is regarded as an interaction system, and the three-dimensional numerical modeling is carried out, and the governing equations are solved by using the non-steady state method of computational fluid dynamics (CFDs). The effects of different underlying surface types, solar radiation intensity and other factors on the urban near-geothermal environment are analyzed through the measured data, and the validity of the numerical results of the road-gas response model is verified. The effects of solar radiation and road material characteristics on the near-geothermal environment in the building group are calculated and analyzed by using the road-gas response model. The air temperature distribution over different pavement is summarized. The main conclusions are as follows:. The results are as follows: 1. The test method of measuring the surface reflectance of pavement by using two total solar radiation meters is put forward and the local true solar time is 11: 00 / 13: 1. The mean value of 00 is used as a surface-reflectance calculation method .2 based on the computational fluid dynamics (. CFDs method. Considering the solar short-wave radiation, heat conduction, convection heat transfer and effective long-wave radiation between pavement and atmosphere, a three-dimensional finite element analysis model of road-gas response is established. The results of 3D finite element analysis show that the proposed model has good accuracy for temperature simulation in daytime period, but at night time. The simulation accuracy needs to be further optimized in the range of 0 ~ 60cm above the grass pavement during the sunny day, and the temperature fluctuates greatly. For the hard impermeable pavement and cement pavement, the simulation accuracy needs to be further optimized. The height range is 0 ~ 50 cm ~ (-1) ~ 0 ~ 100 cm 路m ~ (-1) respectively. For most impermeable surfaces, the air temperature distribution over the road surface during the daytime period can be divided into three types, namely: sunrise type. Day time, evening time 4. 4 for Chongqing Jiefangbei business district. The distribution area of the high temperature area in the road surface temperature field with asphalt material as the underlying surface is obviously larger than that of the high temperature area with cement and hard impermeable pavement as the underlying surface, and the temperature value is relatively high. Thus, it can be seen that the distribution area of the high temperature area in the road surface temperature field is higher than that in the cement and hard impermeable pavement surface. Asphalt pavement has higher absorptivity and specific heat due to its higher absorptivity than cement, so it is not suitable to use it as the underlying surface of residential area or commercial pedestrian street. 5 for the surface temperature of pedestrian road and temperature above it. The average temperature value in the region decreases with the increase of reflectivity, emissivity, thermal conductivity, specific heat and so on, but the amplitude of temperature decrease gradually with the increase of height. With the increase of surface reflectivity 0.1, the average surface temperature decreases 0.6 鈩，

本文編號：1425719