Flyover Simulations and Noise Scenarios- FLYO®
REGISTERED AT EUIPO ON 21/06/2019 under No.018017579
Main Features
- 80 a/c types with total max. 200 noise sources
- each monopole source characterised by LW(f) and DI(j,q)
- > 100 flight paths, each max. 5,000 segments
- > 80 a/c types per path, each with 3 possible time periods for operating (day/evening/ night) and individual velocity
- max. 999 a/c per type on each path (approx. 8 Mio events per scenario)
- transient operations (e.g., tilt-wing approach to vertiport)
- max. 1,000,000 observer points (imported or pre-defined grid)
- computation in Octaves (31.5 – 16,000 Hz) or 1/3-Octaves (20 Hz – 20,000 Hz)
- A/B/C/D frequency weighting or linear SPL spectra
- > 10 noise metrics implemented
- program environment: Windows 10/11 or macOS 11
Main Output
- Averaged SPL per a/c in scenario (spectral if no grid compuation)
- Computation grid (geometry)
- Level vs. Time per a/c type, path and obeserver (single events only)
- Level vs. Time per noise source
- Averaged SPL spectrum per a/c type for each path and oberver
- Averaged SPL per path for each observer (spectral if no grid computation)
- Averaged SPL for complete scenario for each observer (spectral if no grid computation)
- SEL per a/c type on each path for each observer
- Areas [km2] for SPL per a/c type, path, overall scenario and selected metrics < 20 dB, 20-30 dB, 30-40 dB … > 90 dB (grid/map computation)
- Level (spectrum) vs. Time for each a/c type, each path at each observer
- Flyover spectra for transient operations (e.g. full footpring of single aircraft)
- Special metrics for overall scenario (including grid/map computations)
- Loudness and Sharpness (single event at each observer)
- Check file (for plausibility check of sound propagation for each source, path and observer)
- Restart file
- Log file


Examples: Noise map for greater Munich aera in the presence of UAM air traffic (left) and noise footprint for a tilt-wing airtaxi at a generic vertiport (right).
[Topografic map: Bayerische Vermessungsverwaltung – www.geodaten.bayern.de“, Creative Commons Namensnennung 3.0 Deutschland Lizenz (CC BY 3.0 DE)]
Aircraft Noise Source Modeling
The following sources and their components can be simulated using well-established semi-empiric methods:
Fan Noise
- Inlet Broadband Noise
- Inlet Tone Noise
- Combination Tones
- Aft Broadband Noise
- Aft Tone Noise
Jet Noise
- Small Scale Mixing Noise
- Transitional/Intermediate-Scale Mixing Noise
- Inner Stream Plug Separation Noise
- Plug/Downstream Shock Noise
- Outer Stream Shock Noise
- Inner Stream (or Single Stream) Shock Noise
Airframe Noise
- Clean wing
- Clean vertical tail
- Clean horizontal tail
- Landing Gear Noise (Nose & Main LG, i.e., 2-wheel and 4-wheel)
- Trailing Edge Flap Noise (single-, double, triple slotted)
- Leading Edge Slat and Flap Noise
Propeller Noise
- Tonal components
- Broadband noise
- Propeller with tilt angle
Helicopter Noise
- Periodic rotational noise / steady and unsteady loading (for main and tail rotor)
- Compressibility-induced profile and drag noise (main rotor)
- Thickness noise (main rotor)
- Blade vortex interaction (BVI) noise (main rotor)
- Broadband boise noise (main and tail rotor)
All of the above listed noise sources can be exported directly into FLYO® formats for further computations.
Aircraft Noise Auralisation
Munich Aeroacoustics is currently testing an own auralisation tool, aiming to generate audio files with focus on UAM air-taxis.
The auralisation will be performed by using the flyover results from FLYO®.