NASA-CR-114760
Noise levels of operational helicopters of the OH-6 type designed to meet the LOH mission
contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
date accessioned | 2017-09-04T15:10:47Z | |
date available | 2017-09-04T15:10:47Z | |
date copyright | 01/01/1973 | |
date issued | 1973 | |
identifier other | LSHOEEAAAAAAAAAA.pdf | |
identifier uri | http://yse.yabesh.ir/std/handle/yse/9136 | |
description abstract | Formulas relating overall sound pressure level (OASPL) to parameters such as horsepower required, tip speed, and thrust for main and tail rotors are presented for standard and quieted helicopters. Formulas relating OASPL to engine parameters such as horsepower output and percent power turbine rpm are presented for unmuffled and muffled engines. The linear scale was used in preference to any of the weighted scales because it resulted in more consistent agreement with the test data when the SPL is expressed in the usual parameters of tip speed, thrust generated and power required. It is recognized that the linear scale does not adequately reflect hearing response, and hence is not a good absolute measure for detection by humans. However, linear OASPL is believed to be useful as a relative means of comparing noise level variations of individual components in similar helicopters with reasonably modest design changes. | |
language | English | |
title | NASA-CR-114760 | num |
title | Noise levels of operational helicopters of the OH-6 type designed to meet the LOH mission | en |
type | standard | |
page | 64 | |
status | Active | |
tree | NASA - National Aeronautics and Space Administration (NASA):;1973 | |
contenttype | fulltext | |
subject keywords | ACOUSTIC MEASUREMENT | |
subject keywords | ACOUSTIC PROPERTIES | |
subject keywords | AERODYNAMIC CONFIGURATIONS | |
subject keywords | AERODYNAMIC NOISE | |
subject keywords | HELICOPTER PERFORMANCE | |
subject keywords | NOISE INTENSITY | |
subject keywords | NOISE PROPAGATION | |
subject keywords | OH-6 HELICOPTER | |
subject keywords | ROTOR AERODYNAMICS |