Design and study of mini wind tunnel for microsystems fluid interaction under low Reynolds number flows

Abstract

This paper discusses details of design and fabrication of a simple open-loop modular mini wind tunnel for studying fluid microstructure interaction under low Reynolds number. A simple open-loop modular mini wind tunnel was designed and built after examining various design possibilities. The mini wind tunnel consists of five basic sections, namely wide-angle diffuser, settling chamber, contraction section, test section and exit diffuser. The settling chamber consists of flow straighter made from array of circular tubes. Mini wind tunnel is powered by incorporating a fan which provides air flow with Re < 1500. Flow behavior inside the mini wind tunnel, particularly test section, was investigated by performing flow simulation using COMSOL finite element modeling. Additionally, smoke experiments confirm streamline flow inside the test section. Fluid interaction of microcantilevers was investigated using the designed mini wind tunnel. Polydimethylsiloxane microcantilever beam of different aspect ratios was fabricated and tested for airflow sensing applications. Microcantilevers are placed normal to fluid flow and steady tip deflection.