Flow structures generated by pressure-controlled self-oscillating reed valves

The flow structures generated by a pressure-con trolled self-oscillating va lve are investigated both experimentally and numerically. Schlieren flow vi sualization experiments show that a stable vortex is developed downstream o f the valve during the closing phase of the valve. During the opening phase of the valve, this vortex moves downstream and dissipates. An experimental study of the vortex interaction with a wedge and cylinder with different d iameters shows that the vortex is a product of the large amplitude of the v alve oscillation and does not significantly affect the valve behaviour. Fin ally, numerical modelling of the flow structures also supports the idea tha t the vortex development is an aerodynamic phenomenon accompanying a large amplitude of oscillation of pressure-controlled self-oscillating valves. (C ) 2001 Academic Press.