Numerical optimisation of a ship wind-assisted propulsion system using blowing and suction over a range of wind conditions. (15th November 2021)

• Record Type: Journal Article
• Authors: Cairns, James; Vezza, Marco; Green, Richard; MacVicar, Donald
• Is Part Of: Ocean engineering. Volume 240(2021)
• Publication Date: 2021-11-15
• Subjects: CFD -- Circulation control -- Coflow jet -- Robust optimisation -- Surrogate model -- Wingsail; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109903
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: A Kriging surrogate model and a genetic algorithm are used to optimise the geometry of a ship wind assisted propulsion system (SWAP). The SWAP device is an actively controlled aerofoil mounted vertically on the deck of a ship in order to produce a forward propulsive force from the wind. The SWAP concept uses a circulation control system which employs both blowing from the leading edge and suction from the trailing edge. The aerodynamic parameters of the sail are found using a computational fluid dynamics (CFD) model validated against experimental data for a similar system, the coflow jet aerofoil. Further application of Kriging models is used to predict maximum lift coefficients for multiple freestream velocities, ensuring that the optimised device offers robust performance and low sensitivity to expected variations in wind speed. The maximum achievable lift coefficient was found to be 13.17% greater than for the baseline aerofoil over a range of wind speeds from 8–12 m/s. Highlights: Coflow jet aerofoils present useful features for use as actively controlled wingsails. Kriging models can predict the relationship between inputs and outputs for coflow jet aerofoils. Coupling of CFD and a surrogate approach performs well optimising an actively controlled wingsail. Reducing the pressure drop between the jet and suction faces is the main driver for increasing lift.