1. 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

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

3. 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

4. PROJECT OVERVIEW

5. 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

6.  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

7. Project Breakdown

8. Detailed Project Breakdown

10. Customer Needs

11. Engineering Specifications

12. 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

13. The Plan (MSD I)

15. The Plan (MSD II)

16. Risk Assessment

18. Most Important Risks

19. ENGINE TEST RIG

20. Schematic

21. Current Engine Set-up

22. ENGINE CHARACTERIZATION

23. Sound Testing Procedure TOP VIEWFRONT VIEW Exit

24. Formula car Microphone Muffler

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

28. Engine Firing Freq: 53.3

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

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

33. Engine 101.5 96.5 95 91.5 103 99 98 92 100.5 95.5 93 90 98 95 93.5 91 98.5 96 94 89 102 98 95 93 99 95 96 91 101.5 97 94.5 93 20” 40” 60” 120” Sound Pressure Level Map: Top View, Horizontal Plane

34. NOISE ABATEMENT DESIGN OPTIONS

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

36.  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

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

38. Single-pass Concentric Tube Resonator

39.  Formula SAE  Lawnmower rpmf (Hz)λ (m)1/2 λ (m)1/2 λ (ft) 5004.1781.6740.84124.47 10008.3340.8420.4262.23 150012.5027.2213.6141.49 200016.6720.4210.2131.12 250020.8316.338.1724.89 300025.0013.616.8120.74 350029.1711.675.8317.78 rpmf (Hz)λ (m)1/2 λ (m)1/2 λ (ft)1/2 λ (in) 5001720.4210.2131.12373.4 10003310.215.1015.56186.7 1500506.813.4010.37124.5 2000675.102.557.7893.4 2500834.082.046.2274.7 30001003.401.705.1962.2 35001172.921.464.4553.3 40001332.551.283.8946.7 45001502.271.133.4641.5 50001672.041.023.1137.3 55001831.860.932.8333.9 60002001.700.852.5931.1 65002171.570.792.3928.7 70002331.460.732.2226.7 75002501.360.682.0724.9 80002671.280.641.9423.3 85002831.200.601.8322.0 90003001.130.571.7320.7 95003171.070.541.6419.7 100003331.020.511.5618.7 105003500.970.491.4817.8 110003670.930.461.4117.0 115003830.890.441.3516.2 120004000.850.431.3015.6  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)

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

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

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

43. Design I

44. Design II

45. Design III

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

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

48. Absorption Mufflers: Bill of Materials

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

52. Engine Dipole Box Parallel Pipe from Speaker

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

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

59.  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

60. 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

61. 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

62. Sources  www.rit.edu/imagine  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  www.crownaudio.com  Dr. Zheji Lui (Dresser-Rand)