Partitioned time couplings of an aero-mechanical wind turbine problem.

Abstract

Abstract Wind turbine developments have led to more powerful offshore rotor systems, creating complex aero-hydro-servo-elastic behaviors that require numerical analysis. A mutliphysics problem can be modelled using several approaches: a “monolithic” method where the systems are considered as a unique block or a “partitioned coupling” where the different domains are solved sequentially. The latter is the retained technique for this work in which different solvers are related to distinct equations that require independent time discretisations. The focus is set on coupling a wind turbine’s mechanical solver with an aerodynamic code, the latter being modelled through an inviscid vortex method and the structural aspect using a finite element method. The study aims to present the implementation process and comparison of different time integration coupling schemes within a large wind turbine simulation framework where aeroelastic effects are studied on the IEA 15MW wind turbine. A ”Conventional Serial Staggered” (CSS) scheme is used as a reference coupling technique, allowing independent time integration while limiting coupling to a single time step. Alternatively, a resembling “subcycling” architecture is proposed and implemented to remedy cases with different temporal discretisations and reduce computational costs of CSS when using the inviscid vortex method.