Impact of urban morphology on pressure coefficient on building facades and wind velocity in street canyons: The case of Oslo

Abstract

This thesis aims to study how the pressure coefficients and wind velocity will vary within the city of Oslo, with changing urban morphology and aspect ratios. It is common in the modern society to erect high-rise buildings in front of already existing buildings. The study will simulate and investigate how this will impact the wind conditions in the existing urban environment. To achieve this simulation, a CFD tool, Star CCM+ has been used. The geometry that have been used in Star CCM+ is originally gathered from Kartverket and is a SOSI file. A workflow of several programs was needed to finally import this SOSI file as a file format compatible with Star CCM+. An area from Barcode and to Løren in Oslo was chosen, as this has several kinds of urban areas, involving high-rise buildings, low-rise buildings, and older high-rise buildings. This geometry is divided in five different regions to fit Star CCM+ restrictions regarding domain size. An important part of this study was to achieve a good mesh solution and apply appropriate physics setting. Pressure coefficients does vary from region to region, Region 1 with high-rise buildings vary more internally in the region than Region 3 where the building mass is lower and much denser. It is also clear that the velocity is dependent on how dense the buildings are located and the aspect ratio of the streets and buildings.