SimPhonics, Inc.

APU Sound Model APU Sound Model TutorialTutorial

SimPhonics, Inc.

• KC-135R APU

• Sound Recording/Analysis

• V+ Modeling

OverviewOverview

SimPhonics, Inc.

KC-135R APUKC-135R APU

• KC-135R Has Two APU’s– Units are Located in Open Aft Cabin Area– Sound Level is Significant in Cockpit

• KC-135R Has Two APU’s– Units are Located in Open Aft Cabin Area– Sound Level is Significant in Cockpit

SimPhonics, Inc.

Notes on RecordingNotes on Recording

• Need Calibrated SPL Microphone– Record at Source for Model Details– Record in Cockpit for FAA Level D

Certification

• Record Digitally– (24 Bit) Mono– Associate with Instrumentation if Possible

• Need Calibrated SPL Microphone– Record at Source for Model Details– Record in Cockpit for FAA Level D

Certification

• Record Digitally– (24 Bit) Mono– Associate with Instrumentation if Possible

SimPhonics, Inc.

Sound Analysis ToolsSound Analysis Tools

• Adobe Audition– Adobe Systems Incorporated– Edit in Frequency Domain

• Adobe Audition– Adobe Systems Incorporated– Edit in Frequency Domain

SimPhonics, Inc.

Sound SpectrographSound SpectrographTime

FreqBrighter Colors Are Greater Amplitudes

SimPhonics, Inc.

APU Sound ComponentsAPU Sound Components

• Intake/Exhaust Door Open/Close

• Start Motor

• Turbine and Noise Spectra

• Bleed Air Valve Open

• Intake/Exhaust Door Open/Close

• Start Motor

• Turbine and Noise Spectra

• Bleed Air Valve Open

SimPhonics, Inc.

APU Sound ComponentsAPU Sound Components

Start Motor

Door Open

Turbine Bleed Air Valve Open

SimPhonics, Inc.

Enlarged Start SectionEnlarged Start SectionStart Motor

Door Open

Turbine Spool

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Starter MotorStarter Motor

SimPhonics, Inc.

TurbineTurbine

Turbine Discrete Blade Passing Frequency(DBPF – NTSB term)

SimPhonics, Inc.

Turbine RemovedTurbine Removed

Removed Turbine DBPF

SimPhonics, Inc.

Model InputsModel Inputs

• Intake/Exhaust Door Open/Close, Start Motor, Bleed Air Valve

• Discrete Events

• Turbine• Model Based on RPM From Host

• Intake/Exhaust Door Open/Close, Start Motor, Bleed Air Valve

• Discrete Events

• Turbine• Model Based on RPM From Host

SimPhonics, Inc.

V+ APU ModelV+ APU Model

SimPhonics, Inc.

• Very high fidelity model

• V+ and FXDirect enabling technologies

• That was just an APU

• Modular design eases re-use

SummarySummary