Impact of airflow impingment on heat transfer from induction generators in oscillating water columns

Computational Fluid Dynamics models based on the LIMPET OWC turbo generation section were created to investigate how airflow impingement created by a rotating turbine directly upstream increased the heat transfer away from electrical generators as compared to purely axial airflow. Finned and smooth generator casings were compared for the two cooling methods. The CFD results of average heat flux and total heat transfer were compared with results obtained through theoretical and empirical equations applicable to axial airflow acting on smooth and finned surfaces with defined temperatures. During axial flow, the CFD and analytical results for heat flux and heat transfer correlated very well over a range of velocities with a maximum deviation of 4.94%. The highest heat transfer, and thus highest potential power output, was obtained by the finned generator when cooled via airflow impingement.