1. Emily Cobbs Ben Donoghue Dan O’Hare

2.  Dr. Koorosh Naghshineh ◦ Faculty Mentor  Steven Lentz ◦ Industry Mentor, Whirlpool Corporation  Mark Christensen ◦ Industry Mentor, Whirlpool Corporation  Kyle Myers ◦ Project Support, WMU Noise and Vibrations Lab

3.  Standard Model ◦ Venting Length = 64 ft ◦ Commercial Use  Laundromats  Long-Vent Model ◦ Venting Length = 100 ft ◦ Residential use  Apartment Complexes  High-Rise Buildings  Kitchens  Mud-Rooms

4.  Air Intake  Heating Element  Drum Rotation  Exhaust

5.  Modified Motor  Motor Mounting Bracket Modified Motor Standard Motor Modified Motor Bracket Standard Motor Bracket

6. 70.55 dBA 72.59 dBA

7.  Reverberation chamber at WMU Sound Pressure Inside Reverberation Chamber Red: Standard Motor Blue: Modified Motor

8.  Accelerometer Placement ◦ Cabinet (A1)  X (Horizontal) ◦ Base (A2)  Y (Vertical) ◦ Motor (A3)  Y (Vertical) ◦ Bracket (A4)  Tri-Axial Base (A2) Motor (A3)Bracket (A4) Cabinet (A1)

9.  Cabinet Accelerometer  Base Accelerometer Red: Standard Motor Blue: Modified Motor

10.  Higher noise and vibrations seen at 125 Hz octave band  3 potential solutions ◦ Bracket Isolation  Decrease contacting surface area of mounting bracket  Limit vibrations transferred from the motor to the base  Absorptive materials at contact points ◦ Tuned Absorber  Cancel out vibrations caused by motor in the 125 Hz band ◦ Mass Modification  Change mass of motor to influence vibration pathways  Balance mass offset due to modification attachment

11.  Rubber Grommets ◦ Decrease higher vibration frequencies ◦ Increased overall sound pressure level ◦ Increased vibrations on the dryer base Bracket Y Accelerometer Red: Standard Motor Blue: Modified Motor B A

12.  Metal Washers ◦ Reduction in contacting surface area ◦ Better connection to base to eliminate extraneous vibration  No promising reductions ◦ Further investigation not pursued

13.  Frequency Testing Green: Side Strike Blue: Top Strike Red: 45 Degree Strike Top Accelerometer Side Accelerometer 112.5 Hz 98.7 Hz

14.  Cantilever beam with attached mass

15.  Decrease in overall dB was minimal  Vibrations increased on motor  No promising reductions ◦ Further investigation not pursued

16.  67g Mass Addition  115g Mass Addition

17.  Significant reduction in dB  Significant reduction in vibrations  Most promising design ◦ Chosen to test with Whirlpool

18. Δ=1.97 dB Δ=1.34 dB Δ=2.96 dB

19.  Maximum of 16 Tests ◦ 22 Tests conducted  Variability between dryers ◦ Motors ◦ Assembly  Reassembling between tests

20.  Further investigate mass modification ◦ Modify mass and balance of motor ◦ Decrease in 315 Hz band ◦ Decrease in overall sound power level  Do not investigate tuned absorber or bracket isolation ◦ Increased overall noise and vibrations  Dampening of structural noise ◦ Resonant frequencies

21. Questions?