A mixed POD–PGD approach to parametric thermal impervious soil modeling: Application to canyon streets

Abstract

International audienceNumerical simulation is a powerful tool for assessing the causes of an Urban Heat Island (UHI) effect or quantifying the impact of mitigation solutions on local climatic conditions. However, the numerical cost associated with such a tool, which may seem low for a section of mesh within the district geometric model, is quite significant at the scale of an entire district. Today, the main challenge consists of achieving both a proper representation of the physical phenomena and a critical reduction in the numerical costs of running simulations. This paper presents a combined parametric urban soil model that accurately reproduces thermal heat flux exchanges between the soil and the urban environment with a reduced computation time. For this purpose, the use of a combination of two reduced-order methods is proposed herein: the Proper Orthogonal Decomposition (POD) method, and the Proper Generalized Decomposition (PGD) method. The developed model is applied to two case studies in order to establish a practical evaluation: an open area independent of the influences of the surrounding surface, namely a parking lot, and a theoretical urban scene with two canyon streets. The mean surface temperature reduction error remains below 0.52 ˝ C for a cut computational cost of 80%