Evaluation of Water Retentive Pavement as Mitigation Strategy for Urban Heat Island Using Computational Fluid Dynamics
Evaluation of Water Retentive Pavement as Mitigation Strategy for Urban Heat Island Using Computational Fluid Dynamics
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DOI：
10.5572/ajae.2016.10.4.179
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发表时间：
2016-12
影响因子：
1.5
通讯作者：
Aiza Cortes;H. Shimadera;T. Matsuo;A. Kondo
中科院分区：
文献类型：
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作者：
Aiza Cortes;H. Shimadera;T. Matsuo;A. Kondo
本文以一个真实的城市街区的主干道为研究对象，评价了粉煤灰保水性路面或WRP材料的使用效果。结合计算流体力学与路面输运（CFD-PT）模型，研究建筑物冠层与地表的能量平衡。模拟了两种情况下的24小时不稳定分析：情况1，沥青被用作路面材料的所有地面和情况2，WRP被用作主要街道材料。我们的目标是（1）预测日变化的空气温度，风速，地面温度和水分含量;（2）比较地面能量通量。利用CFD-PT耦合模型证明了WRP作为主要街道路面材料会导致地表温度降低。最显著的下降发生在1200 JST时，太阳辐射最强，表面温度下降了13.8°C。这种表面温度的降低也导致了街道表面以上1.5 m处空气温度的冷却。在此期间，情况2中的空气温度降低了0.28°C。随着辐射从1600 JST减弱到2000 JST，蒸发冷却也很小。阴影效应、较高的导热系数和较低的导热系数也有助于降低表面温度。地表降温最终导致气温下降。气温下降的程度与地表温度下降的程度成正比。在能量平衡方面，WRP导致潜热通量最大增加高达255 W/m2，感热通量减少高达465 W/m2。
Here we evaluated the effect of using water retentive pavement or WRP made from fly ash as material for main street in a real city block. We coupled computational fluid dynamics and pavement transport (CFD-PT) model to examine energy balance in the building canopies and ground surface. Two cases of 24 h unsteady analysis were simulated: case 1 where asphalt was used as the pavement material of all ground surfaces and case 2 where WRP was used as main street material. We aim to (1) predict diurnal variation in air temperature, wind speed, ground surface temperature and water content; and (2) compare ground surface energy fluxes. Using the coupled CFD-PT model it was proven that WRP as pavement material for main street can cause a decrease in ground surface temperature. The most significant decrease occurred at 1200 JST when solar radiation was most intense, surface temperature decreased by 13.8°C. This surface temperature decrease also led to cooling of air temperature at 1.5 m above street surface. During this time, air temperature in case 2 decreased by 0.28°C. As the radiation weakens from 1600 JST to 2000 JST, evaporative cooling had also been minimal. Shadow effect, higher albedo and lower thermal conductivity of WRP also contributed to surface temperature decrease. The cooling of ground surface eventually led to air temperature decrease. The degree of air temperature decrease was proportional to the surface temperature decrease. In terms of energy balance, WRP caused a maximum increase in latent heat flux by up to 255 W/m2 and a decrease in sensible heat flux by up to 465 W/m2.