Forces on a submerged sub sea tidal kite in surface proximity

Sub-sea tidal kites, while still at an early stage of development, might be an efficient and cost effective way of extracting energy from marine currents [9]. During normal operating conditions the kite is positioned deep in the water column and would ideally be built neutrally buoyant. For operation and maintenance (O&M) situations, or if a fault occurs, it is important to surface the kite in a controlled manner. While the behaviour of wing like profiles in currents is well understood, the assessment of the behaviour in surface proximity and under wave action is not trivial [1]. We employ an efficient boundary element code called panMARE [2] to simulate the effect of surface proximity and wave current interaction on a sub-sea kite. Comparison with experimental data from [1] demonstrates the suitability of the method to simulate forces on a submerged foil for varying immersion depths and angles of attack. Simulations are then performed to investigate the combined effect of waves and current to inform on the most suitable met-ocean conditions for kite retrieval.