“…Despite the wall having a dimension of 1.67 diameters from the free surface, only marginal changes in power and thrust were observed. McNaughton et al (2023) evaluated, also through towing tank experiments, the effects of inter-rotor spacing in a turbine fence. Their results showed a performance uplift of up to 2.8% with an attendant increase in thrust of 1.8% by reducing the inter-rotor spacing from 1.0 to 0.25 rotor diameters.…”