Multiphysics Simulation

Multiphysics simulations are numeric models that involve coupled multiple physical processes. Modelling using the Finite Element (FE) Method is one of the most numerically efficient ways to solve the partial differential equations (PDEs) that describe physical phenomena. FE is particularly powerful for studying phenomena involving the complex interactions between two or more physical processes.

The principal modelling package used by Xi Engineering Consultants is COMSOL Multiphysics and Xi are recognised internationally as COMSOL Certified Consultants. COMSOL provides a true Multiphysics environment providing Xi with the ability to fully couple different physical phenomena to simulated complex behaviour.  Common multiphysics models produced by Xi include acoustic-structural dynamics, acoustic-MEMS, structural dynamics-fluid flow, electrostatic-structural-acoustic and electromagnetic-structural dynamics.

An example of Xi applying multiphysics simulation involved a project where they modelled electrostatic headphones. Electrostatic speakers work by driving a changed elastic membrane between two parallel conductive wire meshes to which an AC signal is applied.  The forces on the membrane vary the AC signal level and with distance to the wire mesh which in turn is dependent on the elasticity of the membrane and internal stresses.  The dynamics are further complicated by the external load of the air on the membrane and visco-thermal losses. Solving such interrelated physics requires a multiphysics approach, which couples structural dynamics, electrostatics and acoustics.