An adaptive port technique for synthesising rotational components in component modal synthesis approaches

Component Modal Synthesis (CMS) is a reduced order modelling method widely used for large-scale complex systems. It can effectively approximate system-level models through component synthesis, in which the repetitive geometrical components are modelled once and synthesised together. However, the conventional CMS only applies to systems with stationary components connected by strictly compatible ports, limiting it from modelling systems with moving components. This paper presents an adaptive port (AP) technique to extend CMS approaches for modelling parametric systems with rotational parts. To demonstrate the capability of the AP technique, we apply it to the Static Condensation Reduced Basis Element (SCRBE), one widely used variant of CMS approaches. The AP-based SCRBE (AP-SCRBE) can enforce the synthesis of rotational-stationary components over a shared adaptive port when the connecting surfaces of two components are discretisation-wise incompatible, which happens when one component moves relative to the others. Numerical experiments on the NREL 5 MW wind turbine show that, in the context of rotational-stationary component synthesis, the AP-SCRBE can accurately and efficiently model the rotating rotor with pitch rotation of blades. It can produce almost identical results to a high-fidelity finite element model at two to three orders faster speeds.