درباره ما
NACA-TN-3996
Investigation of a short-annular-diffuser configuration utilizing suction as a means of boundary-layer control
Year: 1957
Abstract: A straight outer-wall annular diffuser having a center-body length of one-half the outer-body diameter and an area ratio of 1.9:1 has been investigated for mean inlet flow angles of 0° and 19.5° in order to determine the effect of area suction applied on the inner wall. The entrance shape, number, and location of the openings through which the air was removed were varied. The auxiliary air flow was varied from 0 to approximately 4 percent of the main stream air flow; the mean inlet Mach number was approximately 0.26.
For most of the configurations, significant improvement in performance was obtained over no control when a suction flow rate of as little as 1 percent was utilized. Increased rates of suction were responsible for some additional improvements depending on the configuration of suction openings. Rounding the entrance of the suction holes and increasing the area through which suction was applied effectively decreased the auxiliary flow losses and thereby produced higher values of diffuser effectiveness. The diffuser-exit velocity distributions were also improved by the increase in suction area and by an increase in the amount of suction.
For most of the configurations, significant improvement in performance was obtained over no control when a suction flow rate of as little as 1 percent was utilized. Increased rates of suction were responsible for some additional improvements depending on the configuration of suction openings. Rounding the entrance of the suction holes and increasing the area through which suction was applied effectively decreased the auxiliary flow losses and thereby produced higher values of diffuser effectiveness. The diffuser-exit velocity distributions were also improved by the increase in suction area and by an increase in the amount of suction.
Show full item record
| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T16:06:02Z | |
| date available | 2017-09-04T16:06:02Z | |
| date copyright | 01/01/1957 | |
| date issued | 1957 | |
| identifier other | RXONEEAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/69265 | |
| description abstract | A straight outer-wall annular diffuser having a center-body length of one-half the outer-body diameter and an area ratio of 1.9:1 has been investigated for mean inlet flow angles of 0° and 19.5° in order to determine the effect of area suction applied on the inner wall. The entrance shape, number, and location of the openings through which the air was removed were varied. The auxiliary air flow was varied from 0 to approximately 4 percent of the main stream air flow; the mean inlet Mach number was approximately 0.26. For most of the configurations, significant improvement in performance was obtained over no control when a suction flow rate of as little as 1 percent was utilized. Increased rates of suction were responsible for some additional improvements depending on the configuration of suction openings. Rounding the entrance of the suction holes and increasing the area through which suction was applied effectively decreased the auxiliary flow losses and thereby produced higher values of diffuser effectiveness. The diffuser-exit velocity distributions were also improved by the increase in suction area and by an increase in the amount of suction. | |
| language | English | |
| title | NACA-TN-3996 | num |
| title | Investigation of a short-annular-diffuser configuration utilizing suction as a means of boundary-layer control | en |
| type | standard | |
| page | 34 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1957 | |
| contenttype | fulltext |