P11221 - Noise Reduction for Internal Combustion Engines Team Leader: Christopher Morehouse Mechanical Engineers: - Julie Maier - Caroline Bills - Ted Zachwieja Faculty Advisor: Ed Hanzlik Customer: Dr. Alan Nye

Agenda Problem Overview Project Objectives Customers and Users Project Flow Chart & Plan Engine Model Overview Design Options Design Feasibility Next Steps Questions & Discussions

Background Noise abatement - growing field Formula SAE Sound Constraints Conventional Methods Reduce Performance No RIT Background in this Field Multiple Applications Possible Customer: Dr. Nye Users: Formula SAE Team EE 2010-2 Team

Project Scope Investigate physics of sound generation and transmission Identify and locate major noise contributors in ICE Analyze and model noise generation of ICE Propose design for noise reduction mechanism Provide background to EE team for parallel ANC project Provide noise reduction demonstrator for Spring 2011 ImagineRIT

Project Deliverables Engine Sound Model ANC System Constraints Demonstrator for ImagineRIT

Project Overview

Project Breakdown

Detailed Project Breakdown

Customer Needs

Engineering Specifications

Relationship Diagram ES 1 Reduce noise level ES 4 Passes B10.2.1 of the SAE Formula rules ES 7 Component Costs ES 12 Change in Engine Max Power

The Plan

The Plan

Risk Assessment

Risk Assessment

Risk Assessment

Research & Benchmarking

Sound is Pressure http://www.school-for-champions.com/science/noise_cancellation.htm

How We Measure Sound Digital Signal Processing Decibel Meters Sound Pressure Indicators

IC Engine Sources Pressure Waves

Engine Model

MECHANICAL DESIGN OPTIONS

Current Design Glass Pack Low Flow Restriction Low Noise Attenuation

Unpacked Concentric Tube Resonators Design #1: Single-pass Design #2: Multi-pass Passive http://www.eastsidemufflers.com/mufflers.htm

Design #1: Single-pass

Design #2: Multi-pass

Packed Concentric Tubes Design #3: Metal Foam Design #4: Full Length of the Exhaust System Design #5: Rock Wool and Stainless Steel Wool www.stainlessworks.net

Designs #3 & #4: Metal Foams www.bundesregierung.de

Foams Permeability Pore Size Level of Reticulation Absorption Area Length Curves Thickness Scott Acoustical Laboratories

Foams www.bundesregierung.de

Optimal Foam Structure Industrial Noise Control Handbook. Cheremisinoff and Cheremisinoff

Absorption Area Industrial Noise Control Handbook. Cheremisinoff and Cheremisinoff

Metal Foams Available in a variety of densities Available in a variety of pore sizes ERG Duocel Test kit en route Aluminum Copper Silicon Carbide Reticulated Vitreous Carbon (RVC)

ERG Duocel Metal Foams ERGaerospace.com

Design #5: Rock Wool A fibrous insulation made from basalt Custom Muffler and Auto Repair, LA Cone Engineering, Inc., CA MagnaFlow Exhaust

Rock Wool

Design #7: Exhaust Silencer Insert Applied to exhaust tip Reflects Sound Waves back into exhaust stream

Design #8: Active Single-pass

Design #9: Active Multi-pass

ELECTRICAL DESIGN OPTION

Design #10: Active Noise Cancellation (ANC) This generates more sound by the adding of two waves.

ANC continued Introducing a wave 180 degrees out of phase of the targeted noise being cancelled.

Dominating noise comes from the muffler How ANC Applies to Cars Three Major components of sound generation occur in a car Dominating noise comes from the muffler

Feed Forward Control

Feedback Control http://focus.ti.com.cn/cn/lit/an/spra042/spra042.pdf

Installation Options

CONCEPT SELECTION

List of Design Options Current Glass Pack* Unpacked Concentric Tube Resonator Multi-pass Resonator Metal Foam* Entire Length of Exhaust System Wrapped Lava Rock/Rockwool and Stainless Steel Wool* Multiple Exhaust Pipes (Combination) End Cap Silencer (Combination) ANC Variable Length Resonator - Single Pass Variable Length Resonator - Multiple Pass

Criterion List

Simple Concept Matrix

Simple Concept Matrix (cont.)

Simple Concept Matrix (cont.)

Weighted Concept Screening Matrix

Weighted Concept Screening Matrix

Weighted Concept Screening Matrix

Results

Resulting Design Options Unpacked Concentric Tube Resonator Packed Concentric Tube: Metal Foam Lava Rock/Rockwool and Stainless Steel Wool Variable Length Resonator - Single Pass ANC (End Cap Silencer, Multiple Exhaust Pipes)

Critical Action Items Action Item Goal No Later Than Design Commitment Oct. 15 Data Collection (CB) Oct. 14 Oct. 21 Engine Model (CM) Oct. 18 Oct. 25 Design Resonator (JM) Oct. 22 Oct. 25 Detailed BOM & Budget (CB) Oct. 29 Detailed ANC Component Requirements (TZ) Oct. 22 Oct. 29 Detailed ANC Layout & Mounting Schematic (TZ) Oct. 29 Nov. 1

Sources http://www.eastsidemufflers.com/mufflers.htm Picture Sources Slide 1 http://www.motorcycle-usa.com/photogallerys/03CBR600RReuro_DetG.jpgSlide2 Slide 2 http://www.emspowered.com/ http://www.motorcycle.com/manufacturer/honda/2003-cbr-600-track-test-1225.html Slide 5 http://www.impactlab.net/2010/07/01/new-drug-could-reverse-hearing-loss-caused-by-loud-noises/ Slide 35 http://www.dirtwerkz.com/images/products/dbdawg/db-Dawg_Black_450.jpg