Can Pedestrian Comfort Analysis Be Introduced at the Concept Design Stage?

Luca Frattari
Global Director
Altair Engineering, Detroit

Luca Frattari
Global Director
Altair Engineering, Detroit

The developed methodology exploits computational-fluid-dynamics (CFD) simulation as a fast concept-design tool to determine comfort performances of design concepts for new high-rise, tall and super-tall building. Concepts can be quickly evaluated within a complex urban environment under wind actions.

The work explores a six-steps design strategy that aims to avoid the risk of discomfort at a pedestrian level by investigating any kind of proposed shape and urban context. The strategy also enables designers to predict the performance of their models to help convince clients of their design proposal.
The presentation contains two sections;

A short introduction will briefly outline how the wind impacts comfort at pedestrian level and what are the standards required for new buildings in urban areas.
In a second section, the potential of the procedure in optimizing the performance of the building concept will be presented; the building model is discretized with grid nodes (mesh) and the shapes are defined as perturbation of the original nodal position. CFD simulation is coupled with advanced optimization producers to rearrange the grid and update the shape.
The proposed design strategy has six steps:
1_Analyses of the site and wind data collections.
2_Definition of standard wind profiles.
3_Evaluation of the building base concept's performances (iteration zero)
4_Definition of the design variables (shapes), constraints (volume) and objective function (minimize induced wind velocity).
5_Search of the best shape variables combination that satisfy all the constraints and reach the established objective.
6_Results post-processing and comfort evaluation
The methodology is applied to a 250m tall tower concept building in Madrid (fig. 1), where for establish the wind comfort, the CFD results were combined with the Dutch wind nuisance standard NEN-8100.