Diffuser with convoluted vortex generator
AssigneeUnited Technologies Corporation
InventorsRobert H. Ealba, Robert W. Paterson, Walter M. Presz, Jr., Michael J. Werle
Life of this patent
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Abstract
A thin, convoluted wall member disposed upstream of the inlet of a diffuser generates large-scale vortices having axes in the downstream direction. The vortices enhance mixing within the diffuser and can also energize the boundary layer, thereby improving diffuser performance and delaying the onset of stall. Greater diffusion angles without stall are possible. The member itself creates low losses.
Claims30
A diffusing device including a conduit for carrying a fluid in a downstream direction, said conduit having wall means, said wall means having an internal flow path defining surface, said conduit including an upstream fluid delivery portion having an outlet end with a first cross-sectional flow area, a downstream fluid receiving portion having an inlet end of second cross-sectional flow area larger than said first cross-sectional flow area, said wall means interconnecting said outlet end and said inlet end whereby fluid diffuses while traveling downstream from said outlet end into said fluid receiving portion, a thin, vortex generating wall member disposed within said fluid delivery portion upstream of said outlet end and having oppositely facing downstream extending flow surfaces, an upstream edge and a downstream edge, said member having a convoluted portion comprising a plurality of adjoining, alternating, U-shaped lobes and troughs extending in the direction of bulk fluid flow adjacent thereto and spaced from said internal flow path defining surface and terminating at said downstream edge, the tough depth and lobe height increasing in the bulk fluid flow direction, the shape and dimensions of said troughs and lobes being selected to insure that each trough generates a pair of adjacent large-scale vortices downstream of said outlet end, the pair of adjacent vortices generated by each trough rotating in opposite directions about respective axes extending in the downstream direction.
A catalytic conversion system including a gas delivery conduit having an internal flow path defining surface and an outlet of first cross-sectional flow area, a receiving conduit having an inlet of second cross-sectional flow area larger than said first cross-sectional flow area and spaced downstream of said delivery conduit outlet and including a catalyst bed disposed therein, and an intermediate conduit defining a diffuser having a flow surface connecting said outlet to said inlet, the improvement comprising:
- a thin vortex generating wall member disposed within said delivery conduit upstream of said outlet and having oppositely facing downstream extending flow surfaces, an upstream edge and a downstream edge, said member having a convoluted portion comprising a plurality of adjoining, alternating, U-shaped lobes and troughs extending in the direction of bulk fluid flow adjacent thereto and spaced from said internal flow path defining surface and terminating at said downstream edge, said trough depth and lobe height increasing in the bulk fluid flow direction, the shape and dimension of said troughs and lobes being selected to insure that each trough generates a pair of adjacent large-scale vortices downstream of said outlet and within said intermediate conduit, the pair of adjacent vortices generated by each trough rotating in opposite directions about respective axes extending in the downstream direction.
Dependencies are inferred from the claim text.