Acoustic Emissions from F-35 Aircraft during Ground Run-Up
نویسندگان
چکیده
A multi-organizational effort led by the Air Force Research Laboratory conducted acoustic emissions measurements on the F-35A and F-35B aircraft at Edwards Air Force Base, California in September 2013. These measurements followed American National Standards Institute/Acoustical Society of America S12.75-2012 to collect noise data to support community noise modeling and ground personnel noise exposure assessments. This field study utilized the most spatially extensive measurements of a military jet aircraft to date. In total, the microphone array was composed of 235 unique locations. These locations ranged from radial distances of 3 m outside the shear layer to 1,220 m from the aircraft with angular positions ranging from 0° (aircraft nose) to 160° (edge of the exhaust flow field). The acoustic emissions of the F-35 are presented for engine powers from idle to full augmented power (maximum afterburner). The acoustic emissions are characterized with spatial maps and are discussed in terms of overall and spectral band levels as well as statistical skewness measures. The directivity of the F-35 is described in general and in terms of variations in radial distances and individual spectral bands. Additionally, nonlinear propagation effects are identified and described along the peak radiation region for the range of engine powers.
منابع مشابه
Modeling Far-field Acoustical Nonlinearity from F-35 Aircraft during Ground Run-up
The high noise levels associated with full-scale military aircraft result in nonlinear propagation, which results in acoustic shock formation and can alter noise perception. This propagation has been modeled for other aircraft but previous studies have been limited in scope, showing results for only select engine conditions and angles. Recent data measured near an F-35B allow for a more complet...
متن کاملCharacterizing acoustic shocks in high-performance jet aircraft flyover noise.
Acoustic shocks have been previously documented in high-amplitude jet noise, including both the near and far fields of military jet aircraft. However, previous investigations into the nature and formation of shocks have historically concentrated on stationary, ground run-up measurements, and previous attempts to connect full-scale ground run-up and flyover measurements have omitted the effect o...
متن کاملAcoustical Environment of an F-35B During Vertical Landings
Measurements of the sound field near an F-35B during vertical landing operations are reported. Data are presented and discussed from the approach, hover, and descent of the aircraft, and compared with ground run-up measurements. Overall levels are comparable to published values for the F-35A at 50% engine thrust ratio during ground run-ups. Onethird-octave spectra are also presented, and spectr...
متن کاملNonlinear Evolution of Noise from a Military Jet Aircraft during Ground Run-up
Nonlinear propagation of noise measured during static run-up measurements of a military jet aircraft is considered. Measurements made of the noise radiation from the F35AA Joint Strike Fighter indicate levels commensurate with finite-amplitude sound propagation, both through a Gol’dberg number analysis and numerical modeling. Comparisons with a nonlinear propagation model based on the generaliz...
متن کاملRepresenting the Dispersion of Emissions from Aircraft on Runways
Aircraft in their takeoff ground run constitute an unavoidable strong source of emissions subject to a highly variable motion. The intermittent nature of release makes it difficult to measure the emissions and establish their impact on mean concentrations in the vicinity of airports. Practically, it is also difficult to perform experimental studies near taxiways and runways. Remote observations...
متن کامل