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NACA-TN-3669
Perforated sheets as a porous material for distributed suction and injection
Year: 1956
Abstract: Measurements were made of perforated metal sheets having the resistance to air flow of a series of open areas ranging from less than 1 percent up to 41 percent. The results showed that the permeability of a perforated sheet is governed principally by its open-area ratio. The number of holes per square inch, the sheet thickness, and the shape of the individual holes had little or no effect on permeability.
As a porous material for boundary-layer-control applications by means of distributed suction or injection, punch-perforated sheets can be made to any desired permeability. For these applications it is usually necessary to have different permeability at different locations. To achieve a gradient permeability, the size and/or spacing of the holes in successive rows can be varied commensurately with the prescribed variation in permeability. Gradient permeability also can be achieved with uniformly perforated sheets combined with some form of resistance backing to furnish the gradient effect.
As a porous material for boundary-layer-control applications by means of distributed suction or injection, punch-perforated sheets can be made to any desired permeability. For these applications it is usually necessary to have different permeability at different locations. To achieve a gradient permeability, the size and/or spacing of the holes in successive rows can be varied commensurately with the prescribed variation in permeability. Gradient permeability also can be achieved with uniformly perforated sheets combined with some form of resistance backing to furnish the gradient effect.
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T15:30:27Z | |
| date available | 2017-09-04T15:30:27Z | |
| date copyright | 01/01/1956 | |
| date issued | 1956 | |
| identifier other | OAPNEEAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/31832 | |
| description abstract | Measurements were made of perforated metal sheets having the resistance to air flow of a series of open areas ranging from less than 1 percent up to 41 percent. The results showed that the permeability of a perforated sheet is governed principally by its open-area ratio. The number of holes per square inch, the sheet thickness, and the shape of the individual holes had little or no effect on permeability. As a porous material for boundary-layer-control applications by means of distributed suction or injection, punch-perforated sheets can be made to any desired permeability. For these applications it is usually necessary to have different permeability at different locations. To achieve a gradient permeability, the size and/or spacing of the holes in successive rows can be varied commensurately with the prescribed variation in permeability. Gradient permeability also can be achieved with uniformly perforated sheets combined with some form of resistance backing to furnish the gradient effect. | |
| language | English | |
| title | NACA-TN-3669 | num |
| title | Perforated sheets as a porous material for distributed suction and injection | en |
| type | standard | |
| page | 28 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1956 | |
| contenttype | fulltext |