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Noise Control for Internal Combustion Engine Exhaust. Brad Fiedler Chris VanWagenen. Greg Wodzicki Kyle Desrosiers. Design Review – Week 5. Agenda. Introduction / Background Understanding the Problem and Current Technology Courses of Action Course of Action Comparison
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Noise Control for Internal Combustion Engine Exhaust Brad Fiedler Chris VanWagenen Greg Wodzicki Kyle Desrosiers Design Review – Week 5
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 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 Noise Engine Glass pack Exhaust >110dB 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 Noise Engine Active / Passive Noise Cancellation Exhaust <110dB 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 xxxxxxxxxx: • xxxxxx Introduction / Background
Project Plan xxxxxxxxxx: • xxxxxx 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 Noise Exhaust Engine Understanding the Problem and Current Technology
Understanding Optimal Acoustics Exhaust Stage Noise Exhaust Pressure From Combustion Vacuum Noise Top Dead Center Pressure From Vacuum Understanding the Problem and Current Technology
Calculating Tuned Exhaust Length Noise Exhaust Engine • = 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 Noise Speakers Engine Exhaust + Signal Equations: Noise Reduction: + + Understanding the Problem and Current Technology
Glass Pack • Exhaust Travels through Pipe with Perforated Holes • Sound Insulation Absorbs Sound • Minimal Back Pressure • Least Effective in Reducing Sound Noise Engine Glass pack Exhaust Inner Pipe Housing Sound Insulation Understanding the Problem and Current Technology
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 Noise Engine Turbo Muffler Exhaust Understanding the Problem and Current Technology
Baffle Muffler • Reflects Exhaust Throughout Chamber • Reflections Cancel each other • Most Back Pressure created • Greatest Sound Reduction Noise Engine Baffle Muffler Exhaust Understanding the Problem and Current Technology
Lawnmower Engine xxxxxxxxxx: • xxxxxx Introduction / Background
Courses of Action Noise Reduction Techniques Explored Signal Processing for ANC
Internal ANC with Microphone and Feedback Speaker Noise Engine Exhaust Speaker Signal <110dB Controller Primary Microphone Feedback Microphone Courses of Action
Exhaust in Speaker Chamber Primary Microphone Engine Noise Exhaust <110dB Speaker Speaker Signal Feedback Microphone Controller
Multiple Speaker with Error Microphone Speakers Noise Engine Exhaust Speaker Signal <110dB Controller Primary Microphone Feedback Microphone Courses of Action
Signal Generation:Digital Signal Processing Courses of Action
Filtering Technique 1:Filtered-X Least Mean Squared Filter Courses of Action