Fuel System Noise Reduction

Fuel System Noise Reduction
CAE Study using GT-Suite
Dipl.-Ing. Xiaofeng Chen
Dr.-Ing. Caroline Born
PTi Fuel System, Ford of Europe
20th GT-Conference
Frankfurt, 20th October
Possible Noise Sources of the Fuel System
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Fuel Tank Sloshing
Fuel Pump Noise
Valve Noise (e.g. Purge Valve)
Fuel Line Roar Noise
PTi Fuel System - X.Chen, H.Dines, C.Born
Ford Motor Company
2
Fuel Line Roar Noise: CAE study using GT-Suite

Roar Noise on fuel return line
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The CAE Model
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Low Pressure (LP) Fuel System
Modeling of High Pressure (HP) Fuel Pump
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Natural frequency analysis
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Results
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Natural frequency of LP system
Pressure, flow and effect
CAE correlation with test
Summary
PTi Fuel System - X.Chen, H.Dines, C.Born
Ford Motor Company
3
Roar Noise on Fuel Line
What is roar noise?
 A distinctive vibrational noise audible in the vehicle interior.
 Frequency: Broadband Noise
 Typical RPM range: 1800 – 2500 rpm
 Running conditions: Neutral, 1st gear and 2nd gear run up / run
down
Baseline Condition
Interior noise
PTi Fuel System - X.Chen, H.Dines, C.Born
Tank Return line vibration
Front Return line vibration
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
4
Roar Noise – Transfer Path
Animation of pressure pulsation
2) Response
2EO pulsation travels down the
return line and interacts with low
pressure fuel line resonance
due to pipe dimensions
1) Excitation
2EO pulsation generated
in the LP side of the FIP
3) Transfer path
Vibration transfers across the
fuel line clips to the body
4) Noise radiator
Vibration from clips excites
the vehicle body structure
which radiates noise into
the vehicle interior
Ford Motor Company
5
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Test
Model
CAE results
Motor
Company
- Confidential
results
Summary
Possible Countermeasure
NVH Countermeasures
 Rubber hose
Damping by absorbing energy
 Air Damper
Damping by pumping effect of trapped air
 Resonator 50mm
Damping by flow expansion
 pressure and cavity
 Resonator 60mm
Damping by flow expansion
 pressure and cavity
All 4 variants of countermeasure and the baseline will be investigated
with CAE and vehicle tests
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
6
System layout and HP pump model
Volume change of Cam (mm^3)
Plunger Lift (mm/°)
Modelling HP Pump:

1 in, 4 out (Cam Room)

Pulsation driven by volume
change of Cam Room due
to Plunger displacement
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Noise
Model
CAE results
Test
results
Summary
7
Entire CAE Model
Control Factors:
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P-feed
P-tank
T-fuel
Threshold of
Overflow Valve
Engine Speed
Fuel Flow
…
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
8
CAE results
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
9
Natural frequencies of the LP hydraulic system
Critical
engine
speeds
15 Hz
/450rpm
60 Hz
/1800rpm
50 Hz
/1500rpm
30 Hz
/900rpm
Pump event is in 2nd engine order
Air Damper
PTi Fuel System - X.Chen, H.Dines, C.Born
10
Roar
Noise
Model
CAE results
Test
results
Summary
Calculated pressure after NVH fixes
in different designs
1500rpm
Pulsation is in 2nd engine order
Pressure pulsation: Worst to best
Base>60mm>Rubber hose>Air Damper
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
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
The ‘same’ back pressure in
different designs
Oscillation is damped
Motor
Model Company
CAE results
Test
results
Summary
NVH-fixes
11
Pressure response to volume change
in Cam Room
1500rpm
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
12
Air Damper
Pressure pulsation (animation)
Pressure (bar)
HPP  Tank
Air damper ‘isolates’ Pressure Pulsation
ANIMATION
(Base)
ANIMATION
(Damper)
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
13
CAE correlation with test
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
14
Baseline/800rpm
CAE Result:
P-mean: 0.05 bar
P-oscil.: 0.39 bar
Test Result:
P-mean: 0.23 bar
P-oscil.: 0.44 bar
Gauge Pressure
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Pulsation is in 2nd engine order
(26 Hz for 800rpm)
2 peaks in each period
Oscillations are close(CAE/TEST)
Lower P-mean in CAE
NVH-fixes
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE results
Test
results
Summary
15
Test
P-before
P-behind
Air Damper/1800 rpm
Test result:
P-mean: 1.03 bar
P-oscil.: 0.24 bar
CAE result:
P-mean: 1.8 bar
P-oscil.: 0.22 bar
CAE
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Pulsation is in 2nd engine order
(60 Hz for 1800rpm)
Oscillations are close (CAE/TEST)
Higher P-mean in CAE
Minor P-loss in CAE and TEST
Effective by damping oscillation
CAE
P-mean: ~4 bar
P-mean: ~1 bar
Air damper
PTi Fuel System - X.Chen, H.Dines, C.Born
Ford Motor Company
16
Summary

Critical RPM: 1500 rpm  1800rpm / CAE confirmed by test

Pulsation is in 2nd engine order / CAE confirmed by test
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The effect of NVH countermeasures: / CAE confirmed by test
Air Damper > Rubber Hose > 60mm > Baseline

NVH countermeasures work by damping pressure oscillation (back pressure is the
same in different designs) / CAE confirmed by test

Minor P-loss across air damper/same back pressure in different designs/ CAE
confirmed by test
 General agreement with test and DETAILED information available in CAE
PTi Fuel System - X.Chen, H.Dines, C.Born
Roar
Ford
Noise
Motor
Model Company
CAE Results
Test
Results
Summary
17
Thank You