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

 Improve & challenge the proposed designs  Obtain assistance where needed from attendees Purpose of Review

Agenda  Project Overview  Scope Overview  Customers and Users  Project Flow Chart  Project Plan & Risks  Engine Test Set-up  Engine Test Data  Design Concepts  ImagineRIT Demo Set-up  Expected Outcomes – Near Future Plans  Questions & Discussions

PROJECT OVERVIEW

1. Investigate physics of sound generation & transmission 2. Identify & locate major noise contributors in an ICE 3. Analyze & model noise generation of an ICE 4. Create design(s) for noise reduction mechanism 5. Provide sufficient background to EE team for active noise cancellation system 6. Produce simple engine test stand for proof of concept (ICE = Internal Combustion Engine) Revised Project Scope

 Engine Sound Model ◦ Frequency response for varying RPM ◦ For EE team  ANC System Constraints ◦ EE team will follow  Develop Engine Test Stand  Develop prototype noise reduction mechanical systems  Create demonstrator for ImagineRIT Project Deliverables

Project Breakdown

Detailed Project Breakdown

Customer Needs

Engineering Specifications

Most Important Engineering Specs:  ES 1- Reduce noise level  ES 9 - Internal Exhaust Components Survivable Temp  ES 10 - Internal Exhaust Components Survivable Pressure  ES 15 - Measure sound level according to SAE specs Relationship Diagram

The Plan (MSD I)

The Plan (MSD II)

Risk Assessment

Most Important Risks

ENGINE TEST RIG

Schematic

Current Engine Set-up

ENGINE CHARACTERIZATION

Sound Testing Procedure TOP VIEWFRONT VIEW Exit

Formula car Microphone Muffler

Sound Recording Waveform – Without Muffler Frequency Analysis – Without Muffler (at 10,200 RPM)

Engine Firing Freq: 53.3

Preliminary Lawnmower Data  Test #1: ◦ Cart stationary, Decimeter rotated ◦ Exhaust pointing into alley towards dumpster

Preliminary Lawnmower Data  Test #2: ◦ Cart & Decimeter rotated

Engine ” 40” 60” 120” Sound Pressure Level Map: Top View, Horizontal Plane

NOISE ABATEMENT DESIGN OPTIONS

 Glass Pack ◦ Low flow restriction ◦ Low noise attenuation Current Formula Car Muffler Design

 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) Previous Design Option List

 Current Formula ◦ Honda 600cc ◦ 85hp ◦ 4-Cylinder ◦ 4-Stroke  Lawnmower ◦ Briggs & Stratton ◦ 5.5hp ◦ 1-Cylinder ◦ 4-Stroke Engine Comparison

Single-pass Concentric Tube Resonator

 Formula SAE  Lawnmower rpmf (Hz)λ (m)1/2 λ (m)1/2 λ (ft) rpmf (Hz)λ (m)1/2 λ (m)1/2 λ (ft)1/2 λ (in)  Conclusion : ◦ Resonator not feasible for lawnmower engine Resonator Optimal Length f = (RPM) * n / 120 n = number of cylinders λ = c / f c = speed of sound in air (340.3 m/s)

Helmholtz Resonator  f = Frequency  c = Speed of Sound in Air  L = Length of Neck  A = Cross-Sectional Area of Neck  V = Volume of Chamber

 Narrow frequency band  Active option too large  Will not pursue

Absorption Muffler Design  Three shapes, each: ◦ Length = 12 in ◦ ID = 1in ◦ Thickness = 2in  Four packing materials  Test for optimization of sound absorption

Design I

Design II

Design III

Packing Materials  Metal Foam  Fiberglass  Stainless Steel Wool ◦ Fine ◦ Medium ◦ Coarse  Rockwool

Casing/Inner Tube  Packing Materials: ◦ Stainless Steel Casing ◦ Stainless Steel Inner Tube  Perforated Metal  Sheet Metal  Metal Foam: ◦ Aluminum Casing

Absorption Mufflers: Bill of Materials

Engine Dipole Box Parallel Pipe from Speaker

 Create Engine Test Stand (not cart)  Create posters  Obtain actual car mufflers & dissect  Get both engines ready (fuel & oil)  Get TV & set it up

 Engine fails during demonstration ◦ Have backup engines  Weather ◦ Find alternate location (Machine Shop?) ◦ Get another canopy

 1 – 10’ x 10’ Canopy  2 – Tables (approx. 5’ x 2’)  1 – Table (can be drilled into)  4 – Chairs  1 – TV Screen & accompanying cables  2 – 1hp Briggs & Stratton Lawnmower engines  1 – Laptop  1 – Microphone  1 – Decimeter  1 – Handheld Tachometer

Action ItemGoalNo Later Than Design Commitment Oct. 15 Data Collection (CB)Oct. 14Oct. 21 Engine Model (CM)Oct. 18Oct. 25 Design Resonator (JM)Oct. 22Oct. 25 Detailed BOM & Budget (CB)Oct. 29 Detailed ANC Component Requirements (TZ)Oct. 22Oct. 29 Detailed ANC Layout & Mounting Schematic (TZ)Oct. 29Nov. 1 Critical Action Items

Action ItemGoal No Later Than  Report to EE team 11/711/15  Create Complete BOM11/1211/15  Characterize Lawnmower11/911/15  Finalize Absorption11/911/15  Resonator Demonstrator11/1211/15  Data Analysis SAE car11/1211/15  Order Materials Absorption11/19 New Critical Action Items

Sources   Experimental Investigation of Active Noise Controller for Internal Combustion Engine Exhaust System by: Jian-Da Wu et al.  Industrial Noise Control: Fundamentals and Applications by Lewis H. Bell   Dr. Zheji Lui (Dresser-Rand)