Method of Using Microjet Actuators For The Control Of Flow Separation And Distortion

摘要

A system for controlling unwanted flow separation. One or more microjets are placed to feed auxiliary fluid into a region of suspected flow separation on a surface. If the separation is intermittent, sensors can be employed to detect its onset. Once separation is developing, the microjets are activated to inject a stream of high-velocity gas in a direction that is transverse to the prevailing flow. This injected stream forms counter-rotating vortices in the prevailing flow and thereby transfers momentum from the prevailing flow into the boundary layer proximate the surface.

主权项

1. In a surface placed in a moving stream of gas, a method of controlling flow separation in a boundary layer near said surface, comprising:
a. defining an area of likely flow separation; b. providing at least one microjet, positioned on said surface proximate said defined area of likely flow separation, said microjet having a diameter in the range of 100 micrometers to 2,000 micrometers; c. wherein said microjet is oriented approximately perpendicularly to the direction of flow of said moving gas stream; d. providing a pressurized gas supply connected to said at least one microjet so that said microjet injects a stream of high-velocity pressurized gas into said moving gas stream in a direction which is approximately perpendicularly to said direction of flow; e. said pressurized gas supply having a pressure that is between 14 kPa and 345 kPa greater than a pressure of said moving stream of gas; f. said stream of high-velocity pressurized gas having a velocity that is between Mach 0.4 and Mach 1.0; g. whereby said injected stream of high-velocity pressurized gas creates a pair of counter-rotating vortices in said moving stream of gas, said counter-rotating vortices pulling a portion of said moving stream of gas toward said surface, thereby transferring momentum from said moving stream of gas to said boundary layer.