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NACA-RM-L55L21
A free-flight investigation of the effects of a sonic jet on the total-drag and base-pressure coefficients of a boattail body of revolution from Mach number 0.83 to 1.70
Year: 1956
Abstract: INTRODUCTION
With the penetration of modern high-speed airplanes into supersonic flight regime, considerable interest is being directed toward the effects that propulsive jets have on external drag of nacelles and fuselage after bodies and on the base pressures around the jet exit. Data on base pressures and bottail drag (refs. 1 to 6) have shown that power-on drag coefficients may be considerably lower than the power-off drag coefficients. The magnitude of the difference in drag coefficients depends on the after body-geometry, nozzle-design, and jet-operating conditions.
In a much as there is no adequate analytical method available other than the semi empirical theories for calculating or predicting base pressures, the Langley Pilotless Aircraft Research Division is currently conducting flight tests to determine the effects of a sonic turbojet exhaust on body base pressure and total drag at transonic and supersonic speeds. The initial results, reported in reference 6, simulated a sonic turbojet exhaust at 35,000 feet altitude. The present investigation utilizes lower jet static-pressure ratios which correspond to flight at lower altitude.
Two research models with identical configuration, but with different jet static-pressure ratios, propelled with turbojet simulators (designed according to ref. 7) were flight-tested at Langley Pilotless Aircraft Research Station, Wallops Island, Va. Power-on data for model 1 covered a mach number range from 0.90 to 1.15 and Reynolds number range, based on body length, from 28.70 X 106 to 35.00 X 106, while that of model 2 covered a mach number range from 1.1 to 1.70 and Reynolds number range from 52.25 X 106 to 59.00 X106
With the penetration of modern high-speed airplanes into supersonic flight regime, considerable interest is being directed toward the effects that propulsive jets have on external drag of nacelles and fuselage after bodies and on the base pressures around the jet exit. Data on base pressures and bottail drag (refs. 1 to 6) have shown that power-on drag coefficients may be considerably lower than the power-off drag coefficients. The magnitude of the difference in drag coefficients depends on the after body-geometry, nozzle-design, and jet-operating conditions.
In a much as there is no adequate analytical method available other than the semi empirical theories for calculating or predicting base pressures, the Langley Pilotless Aircraft Research Division is currently conducting flight tests to determine the effects of a sonic turbojet exhaust on body base pressure and total drag at transonic and supersonic speeds. The initial results, reported in reference 6, simulated a sonic turbojet exhaust at 35,000 feet altitude. The present investigation utilizes lower jet static-pressure ratios which correspond to flight at lower altitude.
Two research models with identical configuration, but with different jet static-pressure ratios, propelled with turbojet simulators (designed according to ref. 7) were flight-tested at Langley Pilotless Aircraft Research Station, Wallops Island, Va. Power-on data for model 1 covered a mach number range from 0.90 to 1.15 and Reynolds number range, based on body length, from 28.70 X 106 to 35.00 X 106, while that of model 2 covered a mach number range from 1.1 to 1.70 and Reynolds number range from 52.25 X 106 to 59.00 X106
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T15:10:36Z | |
| date available | 2017-09-04T15:10:36Z | |
| date copyright | 01/01/1956 | |
| date issued | 1956 | |
| identifier other | LRSWXDAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/8905 | |
| description abstract | INTRODUCTION With the penetration of modern high-speed airplanes into supersonic flight regime, considerable interest is being directed toward the effects that propulsive jets have on external drag of nacelles and fuselage after bodies and on the base pressures around the jet exit. Data on base pressures and bottail drag (refs. 1 to 6) have shown that power-on drag coefficients may be considerably lower than the power-off drag coefficients. The magnitude of the difference in drag coefficients depends on the after body-geometry, nozzle-design, and jet-operating conditions. In a much as there is no adequate analytical method available other than the semi empirical theories for calculating or predicting base pressures, the Langley Pilotless Aircraft Research Division is currently conducting flight tests to determine the effects of a sonic turbojet exhaust on body base pressure and total drag at transonic and supersonic speeds. The initial results, reported in reference 6, simulated a sonic turbojet exhaust at 35,000 feet altitude. The present investigation utilizes lower jet static-pressure ratios which correspond to flight at lower altitude. Two research models with identical configuration, but with different jet static-pressure ratios, propelled with turbojet simulators (designed according to ref. 7) were flight-tested at Langley Pilotless Aircraft Research Station, Wallops Island, Va. Power-on data for model 1 covered a mach number range from 0.90 to 1.15 and Reynolds number range, based on body length, from 28.70 X 106 to 35.00 X 106, while that of model 2 covered a mach number range from 1.1 to 1.70 and Reynolds number range from 52.25 X 106 to 59.00 X106 | |
| language | English | |
| title | NACA-RM-L55L21 | num |
| title | A free-flight investigation of the effects of a sonic jet on the total-drag and base-pressure coefficients of a boattail body of revolution from Mach number 0.83 to 1.70 | en |
| type | standard | |
| page | 20 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1956 | |
| contenttype | fulltext |