A FLOW CONTROL ARRANGEMENT

摘要

Significant noise is generated when turbulence in a free stream encounters an edge such as a leading edge or trailing edge of an aerofoil. The turbulence in contact with the edge causes static pressure fluctuations which radiate the acoustic noise. By providing magnetic or electric field actuators about the edge a impeding force is generated to create a transition zone for the fluid flow reducing static pressure fluctuations and therefore noise radiation. The actuator may comprise permanent magnets or electromagnets whilst the flow is ionised by appropriate ioniser mechanisms in order to facilitate creation of a impeding force through a Lorentz effect.