Passenger Air Vehicles Noise RequirementsYahia Ismail, Steven Morris, Martin Kearney-Fischer, and Nikola BaltadjievAurora Flight SciencesCambridge, MA2019 UC Davis Noise SymposiumJacksonville, FL15 March 2019
Overview Aurora Flight Sciences Passenger Air Vehicles (PAV) Current Noise Certification Design for Quieter PAV – Noise Simulation Tools Design for Quieter PAV – Model and Full Scale Validation Noise Metrics – Loudness vs Annoyance What Would be a Subjective Noise Metric for PAV? Summary2
Current Noise CertificationFAA CFR32016 CFR 14, Chapter 1, Part 36Subpart F2016 CFR 14, Chapter 1, Part 36Subpart H2016 CFR 14, Chapter 1, Part 36Subpart KPropeller Driven Small Airplanesand Propeller-Driven, CommuterCategory AirplanesHelicoptersTiltrotors36.501 Noise limits36.801 Noise measurement36.803 Noise evaluation andcalculation36.805 Noise limits36.1101 Noise measurementand evaluation36.1103 Noise limits
Current Noise CertificationFAA CFR2016 CFR 14, Chapter 1, Part 36Subpart F2016 CFR 14, Chapter 1, Part 36Subpart HPropeller Driven Small Airplanes and HelicoptersPropeller-Driven, CommuterCategory Airplanes2016 CFR 14, Chapter 1, Part 36Subpart KTiltrotorsPAV Could be Certified Under Subpart F, H, K or a new Category4
Design for Quieter PAVMeet Noise Requirements Conceptual Design – Preliminary Tools High Fidelity Simulation CFD/CAA Propeller Stand and Wind Tunnel Testing Full Scale Flight Test Validation5Full Use of Noise Simulation and Testing to Achieve Noise Objectives
Conceptual Design ToolsOpen Rotor Noise Footprint Use preliminary noisemodels to make a quickassessment of noisefootprintObserverObserver Different levels of fidelitybased on where we are inthe design phase Different noise metricscan be estimated for agiven mission and vehicleSideline(m)ObserverRange (m)6ObserverContour Plot of Overall Sound Pressure Level Over a Simple missionusing four different levels of fidelity
High Fidelity SimulationRotor Design, Vehicle Interaction, Full Vehicle NoiseSOURCE PREDICTION - Star-CCM /PowerFLOW URANS/DES/LBM CFD – Source Prediction(high computational cost simulation)Example multirotor sourceinteraction analysis from Wave6ACOUSTIC PROPAGATION - Wave6 Ffowcs Williams - Hawkings Model Acoustic Finite Element Analysis Statistical Energy AnalysisFULL VEHICLE NOISE PERFORMANCE High Fidelity Rotor Geometry Design Multirotor Interaction Effects Rotor-Vehicle Interaction Effects Interior Noise7Use State of the Art Noise Simulation to Predict Noise with Accuracy
Component and Wind Tunnel Testing Prop Stand toperform full scalepropellerperformance andacoustics testingBoeing Anechoic Chamber Array ofmicrophones tomeasure rotornoise at severalobserver locations Use of Boeingnoise laboratoryanechoic chamberfor propellerperformance andacoustics testing8Acquired five new class 1sound level meters thatcan acquire /- 1 dBaccuracy, narrowbandfrequency resolution up to 20 kHzWind Tunnel and Propeller Stand Testing To Verify Design
Full Scale Validation and CertificationRace track for flyover Full scale noisevalidation will beconducted using anarray of microphonesto verify vehicle noiselevels for a givenbackground The microphone arraywill comply with CFR14 measurementlocations All measured data willbe corrected forperformance andweather referenceconditions9Flight TrackTest AirplaneSidelineMicrophonesGround StationUnder Flight PathMicrophone ArraySidelineMicrophonesAcquire Data
What Would be a Subjective Noise Metric for PAV or SimilarVehicles?10
Noise Perception Perceived loudnessdepends on frequencycontent of noise source Noise deltas are moreimportant than absolutes Noise backgrounds andinteractions can result incomplex perceptionpattern11Annoyance can be highly subjective, including cognitive bias.
Rural Vs Urban Areas In QuieterRural andSuburbanareas, tonelevels will bedistinguished In Urban areasmany of thetones will bemasked by thebackgroundRural Areas12Urban/Suburban Areas
Current Projected Open Rotor Performance Against UrbanBackground Rotor blade pass frequencies High spikes will be noticeableProjected PAVSpectral Irregularity and Background Noise Has Significant Impact on Perceived Noise13
Noise Requirements for PAV Based on Urban and Suburban background noise, a conventional metric maynot be sufficient for the PAV Whether we use dBA, SEL or EPNdB, background noise has to beconsidered14
Summary15 Aurora Flight Sciences Successfully Completed its First Flight Testing of a Passenger Air Vehicle (PAV) ata test site in Manassas, VA Different Noise Certification Categories (Small Airplane driven propellers, Helicopters and Tiltrotors) thatmay fit the new Passenger Air Vehicles Advanced Noise Simulation Tools from Conceptual to Detailed design Tools, Model Scale Wind Tunnel,Component and Full Scale Noise Validation Flight Testing are used to Design a Quieter Vehicle Background Noise of Different Urban Areas will have significant impact on the Noise Limits Definition forthe new Vehicle Noise requirements or metrics based on Loudness (EPNL) or Annoyance (SEL) need to be defined forthe PAV Category
Summary. 3 Current Noise Certification FAA CFR 2016 CFR 14, Chapter 1, Part 36 Subpart F . 2016 CFR 14, Chapter 1, Part 36 Subpart H . 2016 CFR 14, Chapter 1, Part 36 Subpart K. Propeller Driven Small Airplanes . High Fidelity
Noise Figure Overview of Noise Measurement Methods 4 White Paper Noise Measurements The noise contribution from circuit elements is usually defined in terms of noise figure, noise factor or noise temperature. These are terms that quantify the amount of noise that a circuit element adds to a signal.
Driver or Passenger Squib 1 open AND the stored DTC minutes for Driver or Passenger Squib 1 open is GREATER than the stored DTC minutes for Driver or Passenger Squib 2 by 15 minutes or more Squib 1 is live; Squib 2 was used. Driver or Passenger Squib 2 open Driver or Passenger Squib 1 open AND Driver or Passenger Sq
the noise figure of the receiver. Noise figure has nothing to do with modulation or demodula-tion. It is independent of the modulation format and of the fidelity of modulators and demodulators. Noise figure is, therefore, a more general concept than noise-quieting used to indicate the sensitivity of FM receivers or BER used in digital .
The Noise figure is the amount of noise power added by the electronic circuitry in the receiver to the thermal noise power from the input of the receiver. The thermal noise at the input to the receiver passes through to the demodulator. This noise is present in the receive channel and cannot be removed. The noise figure of circuits in the .
extract the noise figure of the DUT from the overall system noise measurement. This step is referred to as second-stage noise correction, as the DUT’s mea-sured noise figure is corrected based on the gain and noise figure of a second stage, which in this case is the test instrument’s noise receiver.
A noise factor of 1, no degradation in signal to noise, produces a noise figure of 0 dB. HF receiver noise figures will range from about 10 to 20 dB. VHF and UHF receivers will often exhibit a lower noise figure, 8 to 15 dB, to take advantage of the lower atmospheric noise environment found there. The receiver noise figure is primarily a .
Noise Contours 19 Input Voltage Noise 20 Dynamic Reserve 20 Appendix A Remote Programming A-1 Introduction A-1 Commands A-1 Appendix B Noise Sources and Cures B-1 Intrinsic Noise Sources B-1 Johnson Noise B-1 '1/f' Noise B-1 Others B-1 Non-Essential Noise Sources B-1 Capacitive Coupling B-2 Inductive Coupling B-2
2 Marc Levoy Outline examples of camera sensor noise don’t confuse it with JPEG compression artifacts probability, mean, variance, signal-to-noise ratio (SNR) laundry list of noise sources photon shot noise, dark current, hot pixels, ﬁxed pattern noise, read noise SNR (again), dynamic range (DR), bits per pixel ISO denoising by aligning and averaging multiple shots
antenna system Noise Margin Noise Margin. Noise Level ITU-R P.372-13. Noise Level ITU-R P.372-13 Shows 46 dB noise on 160 at 1Hz bandwidth for a quiet rural receiving site 64dB for a residential area receiving site. Noise Level ITU-R P.372-13 Shows 46 dB noise on 160 at 1Hz
Model Year 2015 Fuel Economy Leaders / 5 2015 Model Year Vehicles / 6 Diesel Vehicles / 29 Electric Vehicles / 31 Plug-in Hybrid Electric Vehicles / 33 Compressed Natural Gas Vehicles / 35 Fuel Cell Vehicles / 35 Hybrid Electric Vehicles / 36 Ethanol Flexible Fuel Vehicles / 38
Precision Air 2355 air cart with Precision Disk 500 drill. Precision Air 2355 air cart with row crop tires attached to Nutri-Tiller 955. Precision Air 3555 air cart. Precision Air 4765 air cart. Precision Air 4585 air cart. Precision Air 4955 cart. THE LINEUP OF PRECISION AIR 5 SERIES AIR CARTS INCLUDES: Seven models with tank sizes ranging from
AUTOMOTIVE DEMAND POST COVID-19 -80%-46% 1. Passenger vehicles sales by month including Mini Vans; 2. New passenger car registrations by month, Europe EU26 UK Iceland, Norway, Switzerland 2. 2020 estimate based on BCG analysis; 3. Light Vehicles (LV) include Passenger Vehicles (PV) Sources: Marklines/China Association of Automobile Manufacturers (CAAM), ACEA actuals, Wards Automotive .
Major Lines Regional Segments Local Connections Passenger Safety issues, delays, and high maintenance costs due to at-grade crossings. Limited right-of-way forces passenger and freight trains to use shared track, delaying passenger service. Conflicts also arise between different passenger services that share lines, such as Amtrak and SEPTA.
vehicles powered by alternative energy (basically, electric vehicles, plug-in hybrid electric vehicles and fuel-cell electric vehicles) are twice as energy efficient as current ICE vehicles. 4 Srivastava et al (2010) report that the plug-in hybrid vehicle is the next candidate for replacing existing ICE vehicles. The plug-in hybrid vehicle can .
Noise above 140 decibels causes pain and immediate hearing loss. 3 Long Term Exposure to Noise Our ears can recover from short exposure to loud noise, but over time nerve damage will occur. The longer and louder the noise, the greater chance permanent damage will occur. There is really no such thing as “tough ears” or “getting used to it”. 4. 3 Effects of noise to inner ear Normal .
dynamic logic noise is defined as the variation from the original value . The sources of noise in dynamic logic circuits can be classified into two types i) external noise and ii) i nternal noise . External noise is normally caused by adjacent channel cross talk. These noises are major in deep
IF, low-IF, Y-factor, noise temperature, SSB, DSB, mixer as DUT, mixer noise figure, noise folding, Boltzmann constant TUTORIAL 5594 System Noise-Figure Analysis for Modern Radio Receivers By: Charles Razzell, Executive Director Jun 14, 2013 Abstract: Noise figure is routinely used by system and design engineers to ensure optimal signal .
Noise Figure The Noise Figure (NF) is the increase of noise power from the input to the output of a network “White noise”, or noise power, is constant in RF and microwave frequencies Noise is mainly important on the receiver end due to the low signal strength
Figure 2. MAX2082 total output noise vs. gain. Figure 2 shows that the receiver noise floor in the MAX2082 transceiver at low gains is about 50nV/ Rt. This noise is the output noise contribution of the 12-bit ADC, VGA, and AAF. In a well-designed receiver the ADC should dominate this noise.
Where F rx is the receiver noise figure, F LNA is the LNA noise figure. F MIX is the mixer noise figure, GLNA is the LNA gain. Assuming that the LNA and mixer are the dominant contributors of noise, if the mixer noise figure is assumed to be 10dB, the maximum noise figure of the LNA is 4.5dB. Maximum swing at ADC output is 0.5V.