Marquette University | Milwaukee School of Engineering | Purdue University | University of California, Merced | University of Illinois, Urbana-Champaign | University of Minnesota | Vanderbilt University Investigation of Noise Transmission through Pump Casing Paul Kalbfleisch, Researcher Purdue University Monika Ivantysynova Industry/University Engagement Summit June 6 – 8, 2016
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Investigation of Noise Transmission through Pump Casing...Structure-borne Sound: Structural Vibrations and Sound Radiation at Audio Frequencies. Berlin: Springer. Generation Displacement
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Marquette University | Milwaukee School of Engineering | Purdue University | University of California, Merced | University of Illinois, Urbana-Champaign | University of Minnesota | Vanderbilt University
Investigation of Noise Transmission through Pump Casing
Paul Kalbfleisch, Researcher Purdue University
Monika Ivantysynova
Industry/University Engagement Summit June 6 – 8, 2016
2
Project Overview Major Objectives/Deliverables
Next Steps
• Goal: Incrementally validate noise modeling techniques with experimental results.
• CCEFP: Thrust Area 3, Effectiveness: Noise and vibration, leakage, contamination and human factors.
• Contribution: Understand the generation of noise by swash plate type axial piston machines.
• Handful of competing researchers. • Large simulation errors • Lack sufficient experimental
validation
• Complete experimental modal analysis (month 3)
• Measure displacement chamber and port pressures to verify current hydraulic model (month 6)
• Can industry donate a laser vibrometer?
• Set of measurements that include: • Displacement chamber pressure • Acceleration on the casing • Modal parameter estimation • Sound intensity
• Better understand how internal pressure
forces transmit to external audible noise
3
REU Student 2009 Measurement of sound intensity to estimate total sound power radiation of a hydraulic pump/motor Richard Klop
After Before
Intensity dB ref 1E-12 W
84.4 dB (ref 1E-12 W)
4
Outline
Relevant past research 1. Maha acoustic chamber 2. Sound power measurements 3. Modal analysis 4. Pump noise modelling
• Frequency Response Function Example • More than 1200 FRFs were recorded
Natural Frequencies (Hz)
Damping Ratios (% of critical damping)
50 99
671 98
1066 99
2103 82
2496 53
3529 2
- Accel 1 - Accel 2 - Accel 3
Modal Analysis Results
13
Pump noise source modelling
14
Measured Displacement Chamber Pressure
Pressure Sensor
KISTLER 6005
This will enable precise/direct measurements of the excitation forces that are so crucial for model validation.
15
Structure Borne Noise Source
0 50 100 150 200 250 300 350 400 -200 -100
0
100
200 300
400
500
MX MY MZ
angle ϕ [°] Sw
ash
Pla
te M
omen
ts [N
m]
∆MX
Structure Borne Noise Source
0 100 200 300
20
40
60
80
100
120 Displacement Chamber Pressure
Angle [°]
Pre
ssur
e Δ
P [b
ar]
𝑀X =𝑅
cos2 𝛽�𝐹pi cos𝜑i
𝑧
𝑖=1
𝑀Y = 𝑅�𝐹pi
𝑧
𝑖=1
sin𝜑i
𝑀𝐳 = 𝑅 × 𝑡𝑡𝑡(𝛽)�𝐹pi
𝑧
𝑖=1
sin𝜑i +y
zo
∆ϕ+x
FNSy1
FNSy2
FNSy3FNSy4
FNSy5
ϕi
FNSy
16
∆QHP
50 100 150 200 250 300 350
49
50
51
52
53
54
Angle [°]
Flow
Rip
ple
[l/m
in]
Fluid Borne Noise Source
0 100 200 300
20
40
60
80
100
120 Displacement Chamber Pressure
Angle [°]
Pre
ssur
e Δ
P [b
ar]
0 100 200 300 -30
-20
-10
0
10
20
30
Phi Angle [degree]
DC
Flo
w [L
/min
]
DC Flow (Example 44CC)
QrHPi QrLPi Qri
The discharge flow rate includes: 1. Kinematic flow ripple 2. Compression of the fluid 3. Cross porting due to the design of the
valve plate
Fluid Borne Noise Source
17
Valve Plate Optimization
0 100 200 300
20
40
60
80
100
120 Displacement Chamber Pressure
Angle [°]
Pre
ssur
e Δ
P [b
ar]
Valve Plate
Swash Plate
High Pressure Port
Low Pressure Port
Openings in the valve plate control the connections between the displacement chamber and the pump ports.
Noise generation Volumetric efficiency
Controllability of swash plate
18
Valve Plate Optimization
0.5 1 1.5 20.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
FBNS
SBN
S Valve plate optimization (VpOptim)
Original Design
Valve plate
SB
NS
FBNS
Different vehicles require different priority of FBNS/SBNS.
Master’s Thesis: Computational Valve Plate Design, May 2015
Opportunities: • Design quieter fluid
power transmissions
• Hybrid transmissions require new pump designs
• Improve pump control system by reducing control effort and therefore improving efficiency
19
Valve Plate Results
Peak-to-peak [Nm]
Original 452.97
New 294.36
% reduction 35
50 100 150 200 250 300 350 -200
-150
-100
-50
0
50
100
150
200
angle [ φ ]
Sw
ash
plat
e m
omen
t [N
m]
Maha has performed several valve plate optimization projects Significant reductions in both SBNS and FBNS have been achieved In most of the cases, Industry partners have reported improvements in audible noise.
20
• Tandem unit example
• Linear correlation: 1 being ideal
• Front unit: 0.17 - 0.47 • Back unit: 0.14 – 0.69
• Correlation between noise sources and measure sound power is only mild.
• The placement of the rotating group within the housing influence measurable noise.
Measurement results
21
Current Project
22
Vibro-Acoustics
Vibroacoustics Radiation Propagation
0 100 200 300
20 40 60 80
100 120
Displacement Chamber Pressure
Angle [°]
Pre
ssur
e Δ
P [b
ar]
Pump noise modeling
23
Cremer, L., Heckl, M. and Petersson, B. A. T., 2005. Structure-borne Sound: Structural Vibrations and Sound Radiation at Audio Frequencies. Berlin: Springer.
Generation Displacement Chamber Pressures
Radiation Case to Air
Propagation Wave Travel
Transmission Active to passive
Structural Acoustic Process
24
Task 1: Hydraulic model
Generation Displacement Chamber Pressures
0 100 200 300
20
40
60
80
100
120 Displacement Chamber Pressure
Angle [°]
Pre
ssur
e Δ
P [b
ar]
• Verify current hydraulic model in frequency domain for use with vibration model
25
Task 2: Vibration model
Propagation Wave Travel
Transmission Active to passive
• Experimental Modal analysis
• FEM model of the hydraulic pump case
• Utilize forces found in Task 1 for FEM analysis
• Compare measured pump case vibration to simulation results
26
Task 3: Acoustic model
Radiation Case to Air
Correlate surface vibrations with total sound power
• Measurement of sound power with robot • Develop an acoustic model to predict
audible noise level based on case vibration simulated by Task 2