CFD simulation of urban microclimate: Validation using high-resolution field measurements

Area of Science:

• Environmental Science
• Urban Climatology
• Computational Fluid Dynamics

Background:

• Urban heat stress negatively impacts human health, comfort, and productivity.
• Computational Fluid Dynamics (CFD) simulations are crucial for mitigating urban heat stress.
• High-resolution experimental data is essential for validating urban microclimate CFD models, yet often scarce for real urban areas.

Purpose of the Study:

• To perform and validate CFD simulations of urban microclimate in a dense, heterogeneous district.
• To assess the predictive accuracy of CFD models using high-resolution, on-site experimental data.
• To evaluate the performance of 3D Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations for urban microclimate simulation.

Main Methods:

• CFD simulations using 3D URANS equations for a district in Nicosia, Cyprus.
• Utilized a high-resolution dataset of on-site measurements for air temperature, wind speed, and surface temperature.
• Simulations covered four consecutive days in July 2010.

Main Results:

• CFD simulations predicted air temperatures with an average absolute difference of 1.35°C.
• Wind speed predictions showed an average absolute difference of 0.57 m/s.
• Surface temperature predictions had an average absolute difference of 2.31°C.

Conclusions:

• The study demonstrates the capability of CFD simulations, specifically URANS, to accurately predict urban microclimate parameters.
• Validated CFD models can support effective urban heat stress mitigation strategies.
• Identified deviations between simulated and measured results provide insights for model refinement.