1.Introduction
Several CFD simulations evaluated various solar panel designs. These designs were at different angles and elevations. They were exposed to a wind speed of 128 mph. It revealed drag results for the panels’ lower faces. It compared the drag across different areas within the same design. It also compared the drag among different designs.
When designing solar panel arrays, static weight is only half the equation. The real threat to structural integrity is aerodynamic uplift caused by extreme weather. At Qomaira, we rely on Computational Fluid Dynamics (CFD) to validate these structures before they are built.
In this comparative case study, we analyze and contrast the aerodynamic performance of two different solar racking designs: the “THL 5 DEGREE” and the “Green Roof Portrait”—under severe wind loads of 55.43 m/s.
2.The Engineering Challenge: Measuring Uplift
Our primary goal was to calculate the pressure coefficient (Cp) on the lower surfaces of specific panels across both arrays. The coefficient of pressure is a critical dimensionless number in fluid dynamics used to describe relative pressure throughout a flow field.
By finding the Cp values, we can pinpoint exactly where the wind tries to rip the panels off their rails.
3.Geometry:
Our focus is on how to simplify our geometry in a way that does not affect our desired
realistic results. All the attachments of the panels were excluded, except the
long rails that hold the rows of the panels.
The geometry is divided into two halves by a symmetric plane. We gave names to 10
important panels:
4.Simulation Methodology & Setup
To ensure highly accurate and realistic results, we applied rigorous meshing and turbulence modeling:
- Geometry Simplification: For both designs, minor panel attachments were excluded to streamline the calculation, keeping only the long rails that hold the rows.
- Turbulence Solvers: Because high-speed flows create massive flow separations around panel edges, we utilized advanced solvers. For the Green Roof Portrait design, we utilized the K-Omega SST turbulent solver, which elegantly combines the benefits of K-omega and K-epsilon models. The THL 5 Degree utilized the highly robust BSL K-Omega solver.
- Mesh Density: To capture the boundary layers accurately, the Green Roof Portrait simulation was executed using a dense mesh of 2,597,469 nodes and 14,805,568 elements.
5.Comparative Findings: Where Does the Pressure Hit Hardest?
By tracking 10 critical panel locations across both arrays, distinct aerodynamic behaviors emerged.
5.1. The “First Row” Impact: In both designs, the highest pressure values consistently occur on the North panels facing the incoming wind. However, the intensity differs:
- Green Roof Portrait: The maximum Cp recorded was 0.53 on the
n.edge1panel. - THL 5 Degree: The maximum Cp recorded was slightly higher at 0.57 on its leading edge.
5.2. Pressure Trapping Beneath the Array As the wind moves deeper into the middle of the arrays, the pressure heavily affects the lower surfaces of the panels. Both designs effectively concentrate pressure below themselves. Because the forces act directly beneath the core of the panels, the extreme edge panels feature a side that remains unaffected by this concentrated uplift.
5.3. Structural Elevation Matters
When comparing the two, the “THL 5 Degree” design demonstrated slightly higher overall pressure results. This is largely because the “Green Roof Portrait” design sits on a larger structural base, which acts as a buffer and reduces the total area directly exposed to high-speed wind tunneling underneath the array.
6.Conclusion: Designing for Reality
What does this mean for manufacturers and EPC contractors? It means that aerodynamic loads are not uniform. You cannot design a structural rail assuming the middle of the array experiences the same uplift as the leading North edge.
The data proves that the Green Roof Portrait handles wind loads slightly better due to its base geometry, while the THL 5 Degree will require more robust fastening on its leading edges to survive 55 m/s gusts.
Don’t leave your structural integrity to guesswork. At Qomaira, we provide the CFD validation that turns theoretical designs into market-ready, structurally sound hardware.