Resumen de Adaptive urban modelling for solar energy simulations
Cities face complex problems, where any decision can affect not only the comfort, health and life quality of the people who live there, but also the entire ecosystem that surrounds them, reaching distances from the urban nucleus that surprised the researchers in recent years.
A clear example is the heat island, which is a phenomenon where cities have higher temperatures than their surroundings. It was discovered a few years ago that the heat island has previously unthinkable consequences for its natural environment: for example, it was empirically observed that the heat generated in cities on the west coast of the United States causes a warming that wind currents sweep away and, due to weather conditions, ends up "falling" on the Canadian tundra. As a consequence, this is reducing the ice sheets of northern Canada, which is expected to be a serious problem in the coming years Due to its youth, the study of urban physics has barely being able to explain the behaviour of constituent elements (humidity, heat, wind, pollution, light, etc.) for very small streets or neighbourhoods. However, the large amount of data that involves the geometry of an entire city has made it difficult for these studies to make solid predictions for larger areas.
In this thesis we propose to find solutions that allow extending these simulations to a whole city, trying to take a decisive step to address the treatment and resolution of the massive amount of data involved. For this reason, we propose to study hierarchical systems and to decouple the city into smaller areas, as well as the use of Level-of-Detail techniques and the combined use of procedural techniques as a key to solving this very important but extremely complex problem for modern cities.
The techniques we have developed in this thesis, based on the use of an electrical analogy and the efficient calculation of sky view factors and form factors, make it possible to simulate and study the thermal behaviour of an urban environment taking into account the solar and sky radiation, the air and sky temperatures, and even the thermal interaction between nearby buildings. We also show that it is possible, from a 3D recreation of a large urban environment, to simulate the heat exchanges that take place between the buildings of a city and its immediate surroundings. In the same way, taking into account the terrestrial zone, the altitude and the type of climate with which the simulations are carried out, it is possible to analyse the thermal behaviour of a large urban environment.
In summary, this thesis proposes to address the problem of simulating physical effects in large urban environments through the use of procedural rules and Level-of-Detail techniques, in order to reduce the computational complexity of these simulations, but at the same time trying to maintain an acceptable accuracy in the results for decision-making. The final results show that it is possible to obtain credible results in different study cases, all with reasonable calculation times, with the user being able to adjust the parameters to obtain the desired balance between accuracy and calculation time.
