In this paper we introduce a new multi-vector update quasi-Newton (MVQN) method for implicit coupling of partitioned,
transient FSI solvers. The new quasi-Newton method facilitates the use of ‘black-box’ field solvers and under certain circumstances
can be demonstrated to provide Newton-like convergence behaviour for strongly coupled FSI benchmark problems.We demonstrate
the superior convergence behaviour and robust nature of the MVQN method compared to other well known quasi-Newton coupling
schemes, including the least squares reduced order modelling (IBQN-LS) scheme, the classical rank-1 update Broyden’s method
and fixed point iterations with dynamic relaxation. The quasi-Newton methods are analysed on a suite of strongly coupled FSI
problems, including but not limited to, internal, incompressible flow through a flexible tube where the solid density is an order of
magnitude lower than the fluid density.