Evaluation of wind pressure acting on multi-span greenhouses using CFD technique, Part 1: Development of the CFD model

Abstract

The CFD-computed and wind tunnel (WT)-measured wind pressure coefficients ( C p ) were compared for development of CFD model. First, the y + values were considered to identify the optimum conditions of the first cell height from the adjacent wall. The CFD-computed C p values closely corresponded to the measured C p values when the first cell height was 1.5 × 10 −4 m. The computational domain test and the grid independence test were also conducted to determine the optimum domain size and mesh size. As a result of the computational domain test, the length of the upstream portion was fixed at 3 H ( H = ridge height), and the length of the downstream, side and upper portions were determined to be 15 H , 5 H and 5 H , respectively. The mesh size was designed to be 1.0 × 10 −2 m based on the grid independence test. Using the given design criteria, an appropriate turbulence model was selected, and the Shear stress transport (SST) k – ω model was eventually chosen as the turbulence model. Finally, the computed and measured C p values were compared using statistical indices, demonstrating that the CFD-designed model could accurately compute the C p values.