Wave power absorption by a submerged balloon fixed to the sea bed

Abstract: The possibility of absorbing wave energy using a submerged balloon fixed to the sea bed is investigated. The balloon is in the form of a fabric encased within an array of meridional tendons which terminate at a point at the top of the balloon and at some radius at the bottom. The expansion and contraction of the balloon in waves pump air via a turbine into and out of a chamber of constant volume. A more refined model than that used by Kurniawan and Greaves [Proc. 2nd Offshore Energy and Storage Symposium, 2015] predicts a similarly broad-banded response, but the maximum absorption is less than previously predicted. Both approaches are compared and discussed.