Benoit Beckers

Urban layout optimization framework to maximize direct solar irradiation

Abstract The need to save energy at the urban level leads to study how numerical simulations and optimization methods can help the architects to design buildings and districts with the best possible energetic performances, regarding daylight, warming or cooling, and photovoltaic capabilities. This work presents a study of solar potential maximization over a district and its relation with urban shape. For this purpose, two geometrical models are proposed. The first one is derived from the literature and describes a grid of buildings in open area; the second one studies moderately dense urban configurations with a pre-existent urban-context. A clear sky model is considered to compute direct solar radiation and an evolutionary algorithm is used to optimize the shape and the distribution of buildings inside a fixed area. Results show some clues on the optimal distribution of buildings considering the total direct solar irradiation to be captured by an urban district for various densities and compare the solar potential at different latitudes between 40° and 60°N.

Room impulse response simulation based on equal-area ray tracing

Sound rendering are frequently used to enhance the sense of immersion in virtual environments and multimedia applications. For this purpose, this paper proposes a ray tracing method based on equal-area distribution to simulate room impulse response (RIR). It is efficient and accurate to get the direction of arrival of the direct sound and early reflections. An equal-area distribution was adopted in the process of the sound source emitting. In order to optimize the sound source directivity, the direct sound and early reflections of RIR were mainly concerned. In our experiment, the RIR produced by ROOMSIM was set a reference. In addition, Monte Carlo method of equal-angle distribution was also presented as a comparison. Our proposed equal-area ray tracing (EART) can get a better result for early reflection and later reverberation.

Analysis of cloud distribution effect on daylighting in urban environment

The optimization of natural light is an important criterion for sustainable building in order to reduce the energy consumption due to artificial illumination. This article tackles this problem by using a simple urban case to simulate natural lighting. The main goal is to identify those parameters affecting interior daylighting. The case studied consists in a room oriented north, facing an infinite-wall across a street under an isotropic sky corrected with monthly cloud distribution of two locations at the same latitude. The computation was made using the radiosity method to determine the illuminance inside the room taking into account the sky diffuse radiation and all surfaces reflections. Results of daylighting inside the room were calculated for two values of the exterior wall coefficient of reflection. Preliminary results show that the urban color tend to influence greatly the inner illuminance, and slightly the daily number of hours with a standard visual comfort. (6 pages)