Computational fluid dynamic 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 an electrical generator, and how this could be increased by adjusting the clearance between the turbine tips and shroud. It was found that reducing the clearance had consistent beneficial effects on both the turbine performance and generator cooling due to a greater utilisation of airflow after the tip gap.