The National Academies Press

Currently Skimming:

Pages 28-44

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 28... ... 28 CHAPTER 3. MEASURED AIRCRAFT TAXIING SOURCE NOISE CHARACTERISTICS This Chapter summarizes the available measured aircraft taxi and static noise data. Read the entire page →
From page 29... ... 29 3.1.3. Ronald Reagan Washington National (DCA) Read the entire page →
From page 30... ... 30 MD88 Taxiway Longitudinal Directivity 70 75 80 85 90 95 100 20 40 60 80 100 120 140 160 Directivity Angle (deg) Read the entire page →
From page 31... ... 31 CRJ Taxiway Longitudinal Directivity 70 75 80 85 90 95 100 20 40 60 80 100 120 140 160 Directivity Angle (deg) Read the entire page →
From page 32... ... 32 To use the test stand data for estimating taxiing noise levels it is necessary apply a correction from the SAE AIR to account for the acoustic difference between clean (ICD) and distorted (no ICD) Read the entire page →
From page 33... ... 33 3.1.6. IAD Directivity and Breakaway Thrust Measurement Data A characterization of breakaway thrust from taxiing aircraft noise was successfully made based on measurements conducted at Washington Dulles International Airport (IAD) Read the entire page →
From page 34... ... 34 SAE AIR 5662 Lateral Source Directivity -5 -4 -3 -2 -1 0 1 -90 -75 -60 -45 -30 -15 0 15 30 45 60 75 90 Angle (Deg) Read the entire page →
From page 35... ... 35 X Y Z B737-700 Based on matched INM NPD SEL Data 3000 Lbs Approach Thrust Omnidirectional Spectral Sphere with AIR5662 Lateral Directivity Applied Figure 26. B737-700 AAM 3D source - omni directional sphere with SAE lateral directivity applied. Read the entire page →
From page 36... ... 36 X-Ft Y -F t -50000 0 50000 -40000 -20000 0 20000 40000 SEL-unwt 90 85 80 75 70 65 60 55 50 45 40 B737-700 Omnidirectional sphere Matched NPD under 5k ft X-Ft Y -F t -50000 0 50000 -40000 -20000 0 20000 40000 SEL-unwt 90 85 80 75 70 65 60 55 50 45 40 B737-700 Omnidirectional sphere Matched NPD under 5k ft Lateral Directivity Applied Figure 27. B737-700 AAM ground contour predictions with omni and lateral directivity spheres (+/- 50 k ft) Read the entire page →
From page 37... ... 37 3.2.2. Longitudinal Directivity 3D spheres were created that incorporate longitudinal directivity as obtained from measurements in addition to the lateral directivity discussed above. Read the entire page →
From page 38... ... 38 Normalized Taxi Directivity based on available data, B737-700 -10 -8 -6 -4 -2 0 2 4 6 8 0 15 30 45 60 75 90 105 120 135 150 165 180 Angle from Nose (deg) N or m al iz ed L ev el re : 9 0de g Figure 30. Read the entire page →
From page 39... ... 39 CRJ Taxiway Longitudinal Directivity 60 65 70 75 80 85 90 95 100 20 40 60 80 100 120 140 160 Directivity Angle (deg) Read the entire page →
From page 40... ... 40 B737 Average Ground Idle Spectra 30-50 degrees 40 45 50 55 60 65 70 75 80 85 10 100 1000 10000 Frequency [Hz] Le ve l N or m al iz ed to 7 0 dB a t 1 k H z EventsAVG Event2 Event6 Event15 Test+ICD INM_Dep INM_Arr HMMH B737-300 Madrid 737 A Madrid 737 B Madrid A319 Figure 32. Read the entire page →
From page 41... ... 41 B737 Average Ground Idle Spectra 120-140 degrees 40 45 50 55 60 65 70 75 80 85 10 100 1000 10000 Frequency [Hz] Le ve l N or m al iz ed to 7 0 dB a t 1 k H z DCA Events Average DCA Event 2 DCA Event 6 DCA Event 15 Eng1 INM_Arr INM_Dep HMMH - B737-300 Madrid 737 A Madrid 737 B Madrid A319 Figure 34. Read the entire page →
From page 42... ... 42 impact of changing the spectral class drives the effect of atmospheric absorption over the propagation distances of interest. Appendices A and B in this report use local meteorological conditions in utilizing acoustic measurements for the creation of user defined NPD curves. Read the entire page →
From page 43... ... 43 Noise Change (SEL dBA) per Change in Thrust (kLb) Read the entire page →
From page 44... ... 44 while additional research investigates in further detail the sensitivity of taxi and idle engine noise to changes in thrust. Read the entire page →

From page 28...

... 28 CHAPTER 3. MEASURED AIRCRAFT TAXIING SOURCE NOISE CHARACTERISTICS This Chapter summarizes the available measured aircraft taxi and static noise data.