| 摘要 |
A diffuser comprises a conduit having a cross-sectional area that increases in a direction fluid flow. In one embodiment, the diffuser is used to reduce the incidence and severity of flow fluctuations that occur in an electrostatic deposition apparatus. In some embodiments, the diffuser includes one or more flow control features. A first flow-control feature comprises one or more appropriately-shaped annular slits through which fluid having a greater momentum than a primary fluid moving through the diffuser is injected into the "boundary layer" near the wall of the diffuser. A second flow control feature comprises one or more annular slits or, alternatively, slots or holes that are disposed at appropriate locations around the circumference of the diffuser through which a portion of fluid flowing in the boundary layer is removed. Boundary-layer flow removal is effected, in one embodiment, by creating a pressure differential across such annular slit or slots. Among other benefits, such flow control features reduce any tendencies for flow separation of the primary fluid in the diffuser. |
