Accuracy-preserving IMEX schemes applied to the augmented FSI system for blood flow in viscoelastic vessels

The augmented 1D fluid-structure-interaction (FSI) system of blood flow in viscoelastic vessels is presented and solved with a second-order Implicit-Explicit (IMEX) Runge-Kutta (RK) scheme. The accuracy-preserving property of the scheme is proved and compared with the solution obtained adopting a simpler splitting technique. While the latter scheme reduces to first-order of accuracy when the problem becomes stiff (thus when dealing with viscoelasticity), the IMEX scheme preserves the expected second-order of accuracy.