Noise Control for Internal Combustion Engine Exhaust Brad
Noise Control for Internal Combustion Engine Exhaust Brad Fiedler Chris Van. Wagenen 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 Customer Needs Design Objectives Risk Assessment Gantt Chart
FSAE Formula One Vehicle What year Vehicle is this?
Problem Background Noise Engine Exhaust Glass pack >110 d. B � FSAE rules dictate engine noise under 110 d. B. � Current Passive Noise Control device (Glass pack) holds engine sound from wide range above and below 110 d. B � Current technology is not tuned for optimal noise reduction or engine performance Introduction / Background
Design Objectives Noise Engine Exhaust Active / Passive Noise Cancellation <110 d. B Utilize Active / Passive Noise Cancellation Technology to: � Maintain engine output under FSAE limit of 110 d. B. � Adhere to all FSAE Rules � To not add significant weight to vehicle � Maintain/Improve engine performance � Lower Vehicle Center of Gravity 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 xxxxx: � xxxxxx Introduction / Background
Project Plan xxxxx: � 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 Engine Exhaust Understanding the Problem and Current Technology
Understanding Optimal Acoustics Exhaust Stage Noise Exhaust Pressure From Combustion Vacuum Top Dead Center Pressure From Vacuum Understanding the Problem and Current Technology Noise
Calculating Tuned Exhaust Length Noise Exhaust Engine 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 Signal Equations: Exhaust Noise Reduction: Understanding the Problem and Current Technology
Glass Pack Noise Engin e Exhaust Glass pack Inner Pipe Sound Insulation Housing � Exhaust Travels through Pipe with Perforated Holes � Sound Insulation Absorbs Sound � Minimal Back Pressure � Least Effective in Reducing Sound Understanding the Problem and Current Technology
Turbo Muffler Noise Engin e Exhaust 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 Noise Engin e Exhaust Baffle Muffler � Reflects Exhaust Throughout Chamber � Reflections Cancel each other � Most Back Pressure created � Greatest Sound Understanding the Problem and Current Technology Reduction
Lawnmower Engine xxxxx: � 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 Primary Microphone Courses of Action Controller <110 d. B Feedback Microphone
Exhaust in Speaker Chamber Engine Primary Microphone Exhaust Noise <110 d. B Speaker Signal Controller Feedback Microphone
Multiple Speaker with Error Microphone Speakers Engine Exhaust Speaker Signal Primary Microphone Courses of Action Noise Controller <110 d. B Feedback Microphone
Signal Generation: Digital Signal Processing Courses of Action
Filtering Technique 1: Filtered-X Least Mean Squared Filter Courses of Action
- Slides: 25