CFD Simulation Sample for Roofing Structure

Summary

This case study presented a thermal and shading analysis of a proposed roofing/awning structure using Computational Fluid Dynamics (CFD). The study evaluated both interior and exterior conditions with and without the roof, assessing solar radiation exposure, shading effectiveness, and temperature distribution to understand the thermal impact of the structure.

Introduction

Utilising CFD analysis, the thermal behaviour of the roofing/awning structure was numerically simulated to assess its influence on the surrounding environment. It compared both shaded and unshaded conditions to illustrate how the roof affected solar exposure and temperature levels beneath the structure and within the interior space.

Objectives

The objective of this CFD analysis was to determine whether the roof provided effective shading and reduced surface temperatures beneath the structure and within the interior, compared to unshaded conditions.

Scope of Work

The analysis focused on:

Solar radiation exposure on the surface
Shading effect provided by the roof geometry
Temperature distribution with and without the roof

Methodology

A CFD simulation of the roofing structure and its surrounding environment was developed to evaluate its thermal performance and shading effectiveness. Surface temperature distribution was assessed under identical environmental conditions to quantify the roof’s thermal impact on both exterior and interior areas.

By comparing temperature distributions with and without the roof, the results demonstrated how the roofing structure affected surface heating and the thermal environment beneath it.

Structural Analysis Results

Thermal and Shading Performance: Exterior with Roof

The roof provided effective shading, reducing direct solar radiation.
Surface temperatures beneath the roof were noticeably lower than those of the unshaded exterior area.
Peak surface temperatures were reduced, indicating lower solar heat gain.
Minimum temperature under the shaded area: 35°C
Maximum temperature outside the shaded area: 42°C

Thermal and Shading Performance: Exterior Without Roof

Surfaces were directly exposed to solar radiation.
Higher surface temperatures were observed across the exposed area.
The temperature distribution was not uniform, with localised hotspots corresponding to peak solar exposure.
Minimum temperature under the table area: 45°C
Maximum temperature on the table surface: 56°C

Thermal and Shading Performance: Interior with Roof

Shading reduced solar heat gain on the roof and façade surfaces.
Interior surface and indoor air temperatures were lower and more stable.
Improved thermal comfort and reduced cooling load within the building.
Minimum temperature near the diffuser: 24°C
Maximum temperature at window surfaces: 36°C

Thermal and Shading Performance: Interior Without Roof

Solar radiation directly impacted the building envelope, with higher temperatures concentrated near windows.
Elevated internal surface and indoor air temperatures were observed.
Increased solar heat gain led to reduced thermal comfort.
Minimum temperature near the diffuser: 24°C
Maximum temperature at window areas: 41°C

Conclusion

The CFD analysis showed that the roof provided effective shading, significantly reducing surface temperatures beneath the structure and within the interior compared to unshaded conditions. By mitigating direct solar radiation, the roof improved the thermal environment in occupied areas, demonstrating its effectiveness in reducing heat gain and enhancing comfort.

For more insights, you can also check out our case study on the roof’s structural analysis using Finite Element Analysis (FEA).