Vertical Axis Wind Turbine simulations and measurements

This work presents a comparison of RCS and Doppler spectrograms of a 10 m tall Vertical Axis Wind Turbine using the Physical Optics and Multilevel Fast Multipole Method numerical techniques. The MLFMM results are then compared with measurements. Simulations and measurements were performed at 1.5GHz, 3.6GHz, 5.8GHz, and 9.7GHz corresponding to electrical dimensions of 50λ-323λ. The average RCS using PO and MLFMM over the entire rotation period has good agreements for all frequencies; however, the PO RCS produces irregular Doppler spectrograms. The measured VAWT results have close agreement with the simulations.