| 摘要 |
<p>A nozzle for generating an ultrasonic gas flow has the form of a short section of pipe with a passage of constant cross-section extending from an inlet to an outlet for the gas. Radial drillings in the plane of the constriction of the gas flow perpendicular to the nozzle axis serve to stabilise the constriction axially, and the inlet is so formed that a layer of gas implodes axially into the passage around the main gas flow forming a boundary layer around it. According to the present specification this boundary flow is achieved through a ring of axial orifices around the main inlet orifice, and their dia. is a whole number multiple or fraction of the fundamental wavelength of the pressure wave generated in the main gas stream to within a tolerance of 10%. Higher amplitudes and higher nozzle efficiencies are achieved.</p> |
