BEM for the analysis of fluid flow around MEMs

VICTOR D. FACHINOTTI; ALBERTO CARDONA; JORGE D'ELÍA; STÉPHANE PAQUAY

Córdoba, Argentina

Congreso; XVI Congreso sobre Métodos Numéricos y sus Aplicaciones (ENIEF 2007); 2007

Asoaciación Argentina de Mecánica Computacional

The boundary element method (BEM) is used in this work for modelling the fluid flow around a vibrating micro-electro-mechanical system (MEMS). Device motion induces flow and, therefore, drag-forces develop on the surface of the MEMS with a damping effect on the MEMS vibration. We assume that the fluid around MEMS can be treated as a continuum and, further on, that the flow can be modelled as incompressible with a very low Reynolds number. Under such conditions, met in a large number of MEMS in practice, the fluid flow can be accurately described by Stokes theory of quasi-steady incompressible flow. We take into account MEMS deformation effects on fluid flow analysis. Fast integration is performed using the collocation method. Self-integrals containing singular kernels are analytically computed over linear triangles. This model has been computationally implemented into the engineering software OOFELIE:MEMS, developed by Open Engineering SA. The accuracy of the model is tested using a benchmark problem – the flow around a sphere moving with constant velocity–, with satisfactory results. Preliminary results of an application to MEMS are also shown.