Measurement and simulation of the flow field around the FINO 3 triangular lattice meteorological mast

A numerical and experimental simulation of flow around a complex, three-dimensional triangular lattice meteorological mast and accompanying anemometer booms has been carried out using the open source CFD code OpenFOAM. The simulation has been compared with results using a 1/20th scale wind tunnel model using 3D hot-wire anemometry probes and satisfactory agreement with the CFD has been found. Three turbulence models commonly applied in numerical external aerodynamics were employed with the one-equation Spalart–Almaras model compared with its more sophisticated two-equation counter parts k–ε and k–ω–SST. The differences in the results for the velocity field around the mast were found to be marginal and recommendations for the overall suitability of any individual RANS-based turbulence model for such flows were inconclusive. The predicted flow distortion surrounding the lattice mast differed from previously published data using the method suggested in International Electrotechnical Committee (IEC) standards based on the results specifically for the FINO 3 mast. Using the CFD simulation data it was possible to calculate the optimum boom length to place the anemometers outside of any flow distortion field for this mast. Shorter boom lengths than those suggested by the current IEC standard could potentially be used to place the anemometers beyond the flow distortion zone generated by the met mast. The results highlight the potential of using open-source CFD for the assessment of interference effects on masts with intricate, three-dimensional structural patterns.