hydraulic fluidborne noise measurements
TRANSCRIPT
Vibro-Acoustics Consortium
August 12, 2021
Hydraulic Fluidborne Noise Measurements
David HerrinUniversity of Kentucky
Vibro-Acoustics Consortium
August 12, 2021
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Heavy Equipment Multiple Sources
Washburn and Wood, 2016
Forcing Functions(Source)
Energy Paths(Source)
Example: EngineMechanical Dynamics
Piston Slap Internal Gears Bearing Impacts Etc.
Example: Hydraulics/Hydrostatics
Flow Ripple
Kinematic Component Inertial Component
Fluid-Borne
Radiating Surfaces Reservoir Etc.
Fluid-Borne Path
Engine Structure Radiating Surfaces Front Cover Engine Block Valve Covers Oil Pan
Structure-Borne
Airborne
Sound Emitting Orifices Intake Exhaust
Example: Intake / Exhaust
Combustion
Combustion
Vibration Path Engine Mounts Etc.
Vibration Path Hose / Pipe Attachments Etc.
TemplateSource Side
The source energy paths are characterized by the whether the forcing function is airborne, structure-borne, or Fluid-Borne.
T.O.C.
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β’ Kinematic Componentβ’ Inertial Component
4
Flow Ripple
Pump Pipe Valve and sink
Time (10-3s)
Flow
(10-
1 l/s)
Typical flow ripple for a piston pump:
Edge, 1999
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ISO 15086 Hydraulic fluid power β Determination of fluid-borne noise characteristics of components and systems
Part 1 (2001): Plane wave model in hydraulics
Part 2 (2000): Measurement of speed of sound
Part 3 (2008): Measurement of hydraulic impedance
ISO 10767 Hydraulic fluid power β Determination of pressure ripple levels generated in systems and components
Part 1 (1996): Measurement of source flow ripple and source impedance
Part 1 (2015): Measurement of source flow ripple and source impedance
Standards
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Plane Wave Model
π π₯ π π π π
πΎ π2πππ π
π π₯ π π π π
π2πππ
π: viscosity coefficient
Acoustic Pressure Pressure Ripple
Viscosity Coefficient
π π 1Ξ½
2π ππ
Ξ½2π π
Ξ½π π
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Plane Wave Model
Acoustic Particle Velocity Flow Ripple
π π₯1π π π π π π π₯
1π π π π π
(in air)ππππ
ππππ π
π
Characteristic Impedance Characteristic Impedance
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π π₯ : fluid pressure at location π₯π : incident wave amplitudeπ : reflected wave amplitudeπΎ: wave propagation coefficientπ₯: location in the pipe
Plane Wave Model
Source LoadPipe
π
π
π₯
π π₯ π π π π
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Hydraulic Transfer Matrix
ππ β
π π π π π
π β
1 2 3
π β π β
ππ π
π β π β
ππ β
π π π π π
π β
π β π β 0
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Property Calculations
Viscosity of fluid in pipe
Density of fluid
From handbooks:
From measurement: Speed of sound
Wave propagation coefficient πΎ π
ππ π
π
π
π
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Speed of Sound ISO 15086-2
π β π β
π πππΏ πΏ
1. Assume speed of sound to determined incident and reflected wave using π and π .
2. Determine π and compare to measured π .3. Iterate π until error is minimized.
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Speed of Sound ISO 15086-2
0
400
800
1200
1600
600 800 1000 1200 1400 1600 1800
Erro
r (Ξ΅)
Speed of Sound (m/s)
1344 m/s
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Transmission Loss Two Source Approach
Notes: primary pump is to provide the mean flow pressureand is running at 270 Hz.
Test Component
L2
L1
L3
1 43 62 5
Hose
Primary Source(pump)
Secondary Source
Ball Valve
6 Transducers
Symmetric Setup
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Transmission Loss ASTM E2611
Liu, Suh, and Yang (2017)
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β5
0
5
10
15
20
200 400 600 800 1000 1200 1400 1600
Transm
ission Loss (d
B)
Frequency (Hz)
Transducers 1&2, 4&5Transducers 2&3, 5&6Transducers 1&3, 4&6
Test Component1 43 62 5
Transmission Loss ASTM E2611
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Load valvePressure relief valve
Pressure transducers
Straight rigid pipe
Test pump
Secondary Source
β’ More than 2 pressure transducers can be used for accuracy.β’ π and π are solved at the harmonics of the secondary source.
13 2
Source Impedance ISO 10767-1 (1996)
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ππ
π π ππ
π πππ
Current source: π and π
π
ππ , π
Voltage source: π and π
π
π
π , π
Source Load
Source Impedance ISO 10767-1
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ππ
πΏ πΏ
Connecting Pipe Reference Pipe
Loading Valve
ππ
(a)
π
π
πΏ πΏ πΏ
Extension Pipe Reference Pipe
Loading Valve
πππ
(b)
π
πππ π
1 π1 π
ππ
ππ
Where π 1 πβ
Multi-load approach can be used, and source properties can be solved by least square approach.
Source Impedance ISO 10767-1
Liu, Suh, and Butts (2018)
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Source Impedance Load Selection
Liu, Suh, and Butts (2018)
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Source Impedance ISO 10767-1
Liu, Suh, and Butts (2018)
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Flow Ripple ISO 10767-1
Liu, Suh, and Butts (2018)
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Flow Ripple ISO 10767-1
Liu, Suh, and Butts (2018)
Vibro-Acoustics Consortium
August 12, 2021
References
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β’ J. Liu, S. Suh, and Y. Yang, Hydraulic Fluid-borne Noise Measurement and Simulation for Off-Highway Equipment, Noise-Con, Grand Rapids, MI, June 12-14 (2017).
β’ J. Liu, S. Suh, and T. Butts, Source Flow Ripple and Source Impedance Measurement for Different Hydraulic Pumps, Inter-Noise, Chicago, IL, August 26-29 (2018).