noise control for internal combustion engine exhaust design review – week 5 greg wodzicki kyle...

Noise Control for Internal Combustion Engine Exhaust

Design Review – Week 5

Greg Wodzicki

Kyle Desrosiers

Brad Fiedler

Chris VanWagenen

Agenda Introduction / Background Understanding the Problem and Current

Technology Courses of Action Course of Action Comparison Best Courses of Action Closing Questions

Introduction/Background

Background

Customer Needs

Design Objectives

Risk Assessment

Gantt Chart

FSAE Formula One Vehicle

Click icon to add picture

What year Vehicle is this?

Problem Background

FSAE rules dictate engine noise under 110dB. Current Passive Noise Control device (Glass

pack) holds engine sound from wide range above and below 110dB

Current technology is not tuned for optimal noise reduction or engine performance

Engine Exhaust

Noise

>110dB

Glass pack

Introduction / Background

Design Objectives

Utilize Active / Passive Noise Cancellation Technology to: Maintain engine output under FSAE limit of 110dB. Adhere to all FSAE Rules To not add significant weight to vehicle Maintain/Improve engine performance Lower Vehicle Center of Gravity

Engine Exhaust

Noise

<110dB

Active / Passive Noise

Cancellation

Introduction / Background

Performance Objective

Possible Performance Effects of Different Exhaust Technology: A – No Exhaust Tuning B – Traditional Exhaust Length Tuning C – Possible Active Noise Cancellation Improvement*

* Dependent on cancellation method

Introduction / Background

Risk Assesment

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Introduction / Background

Project Plan

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Introduction / Background

Understanding the Problem and Current Technology

Internal Combustion Engine

ICE Exhaust Acoustics

Tuning a Exhaust

Understanding ANC

Lawnmower Engine

Glass Pack Muffler

Turbo Muffler

Baffle Muffler

Understanding the 4 Stroke ICE

Engine

Exhaust

Noise

Understanding the Problem and Current Technology

Understanding Optimal Acoustics

Exhaust

Noise

NoiseTop Dead Center

Exhaust Stage

Pressure From Combustion

Pressure From Vacuum

Vacuum

Understanding the Problem and Current Technology

Calculating Tuned Exhaust Length

Exhaust

Noise

Engine

𝐿=𝑘∗ (𝐸𝑜∗𝑉 𝑠 )

𝑁

= Crankshaft Speed in RPM = Constant

Understanding the Problem and Current Technology

Understanding Active Noise Cancellation - 1 Superposition Harmonics

Understanding the Problem and Current Technology

Understanding Active Noise Cancellation - 2

Understanding the Problem and Current Technology

𝐴𝑒𝑖𝑤𝑡−𝑖𝑘𝑥

𝐵𝑒𝑖𝑤𝑡−𝑖 𝑘(𝐿¿ ¿𝑡−𝐿1)¿

+

Noise

Engine

ExhaustSpeakers

𝐿𝑡 𝐿1

+

+

Signal Equations:

Noise Reduction:

Glass Pack

Exhaust Travels through Pipe with Perforated Holes Sound Insulation Absorbs Sound Minimal Back Pressure Least Effective in Reducing Sound

NoiseEngin

eExhaust Glass

pack

Inner Pipe

Sound Insulation

Housing

Understanding the Problem and Current Technology

Turbo Muffler

NoiseEngin

eExhaust

Turbo Muffler

No Baffles Exhaust Forced to turn

back and forth Increases Exhaust

Length Increased Back

Pressure with each turn

Sound Insulation Absorbs Sound

Moderately Effective in Reducing Sound

Understanding the Problem and Current Technology

Baffle Muffler

NoiseEngin

eExhaust

Baffle Muffler

Reflects Exhaust Throughout Chamber

Reflections Cancel each other

Most Back Pressure created

Greatest Sound Reduction

Understanding the Problem and Current Technology

Lawnmower Engine

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Introduction / Background

Courses of Action

Noise Reduction Techniques Explored

Signal Processing for ANC

Internal ANC with Microphone and Feedback

Noise

Courses of Action

Engine

Exhaust

<110dB

Speaker

Primary Microphone

Feedback Microphon

e

Speaker Signal

Controller

Exhaust in Speaker Chamber

NoiseEngin

eExhaust <110dB

Speaker

Primary Microphone

Feedback Microphon

e

Speaker Signal

Controller

Multiple Speaker with Error Microphone

Noise

Courses of Action

Engine

Exhaust

<110dB

Speakers

Primary Microphone

Feedback Microphon

e

Speaker Signal

Controller

Signal Generation:Digital Signal Processing

Courses of Action

Filtering Technique 1:Filtered-X Least Mean Squared Filter

Courses of Action