Fuel Line Acoustic Nonlinear Analysis ... - Gamma Technologies€¦ · 2014 Gamma Technologies...
Transcript of Fuel Line Acoustic Nonlinear Analysis ... - Gamma Technologies€¦ · 2014 Gamma Technologies...
2014 Gamma Technologies North America UGM
1
Fuel Line Acoustic Nonlinear Analysis
&
Evaporative Emissions System
Flow Analysis
Eric Myers
Fuel System CAE
Ford Motor Company
November 3, 2014
2014 Gamma Technologies North America UGM
• Fuel line nonlinear acoustic analysis• Problem statement
• Model setup and assumptions
• Results
• Evaporative emissions system analysis• Objective
• Component modeling considerations and correlation
• Evap system model and correlation
Agenda
2014 Gamma Technologies North America UGM
• Customer complaint about a vibrational noise in the
cabin while driving• Occurs on the diesel Fusion powertrain
• Termed “roar noise”
• Noise coming from left side floor
• Noise source isolated to the fuel lines• Fuel line vibrating in clips
• Fuel line clips to frame
• Frame to rear seat foot well floor
Problem Statement: Fuel Line Analysis
2014 Gamma Technologies North America UGM
• No issue from prior model year
• Prior model year used dual plunger high pressure
injection pump (HPP)• Changed to single plunger high pressure injection pump
• Root cause • Pressure pulsations in return fuel line
• Dual plunger pump cancelled/prevented the pulsations
• Single plunger pulsations propagate down fuel lines
Problem Statement: Fuel Line Analysis
2014 Gamma Technologies North America UGM
Diesel Fuel System Overview
High Pressure Injection Pump
Fuel return line (supply line not shown)
Fuel cooler
Fuel injection
common rail
Fuel tank connection
2014 Gamma Technologies North America UGM
Model Assumptions: Fuel Line Analysis
• Roar noise source isolated to fuel return line• Pressure pulsations propagating from pump
• Pulsations induce line vibration
• Considered components• High pressure pump (HPP)
• Return line and fuel cooler to tank connection
• Injection side of pump not required for model• Injector leakage fed back to HPP
• Diesel fuel properties as defined in GT• Includes air content in fuel
• Fuel line materials• Nylon
• Low carbon steel
2014 Gamma Technologies North America UGM
Model Approach: Fuel Line Analysis
• Return line assembly analysis procedure• Nonlinear analysis
• Calculates resonance frequencies
• Monitor pressure waveform through return line
• Used as indicator for noise origination
• Frequency sweep analysis• Simulates pump return flow through frequency range
• Locate max pressure peak within line assembly
• Frequency sweep analysis with rubber hose• Proposed solution to dampen pressure pulsations
• Evaluate effectiveness of hose
• Monitor max pressure peak
2014 Gamma Technologies North America UGM
Model Approach: Nonlinear Analysis
• Determine resonance frequencies• Consider frequencies within HPP operating range
• System driven by white noise source
• System open at tank end, applied nominal line pressure
• Roar noise worst at about 2300 engine RPM• Corresponds to 76.67Hz HPP frequency
• Check for resonance at 76.67Hz
• If not, pulsations purely from pump back flow
2014 Gamma Technologies North America UGM
Results: Nonlinear Analysis
• Resonances
Calculated HPP Operating
Frequency Range
Return Line Assembly Resonance
Frequencies Within HPP Operating
Range
Return Line
Resonance
Frequency
(Hz)
22
46
76
98
124
2014 Gamma Technologies North America UGM
Results: Nonlinear Analysis
• Pressure contour plot @ 76Hz
2014 Gamma Technologies North America UGM
Results: Nonlinear Analysis
• Max pressure pulse location
2014 Gamma Technologies North America UGM
Results: Nonlinear Analysis
• Pressure waveform through return line @ 76Hz
2014 Gamma Technologies North America UGM
Model Approach: Frequency Sweep Analysis
• Perform sweep analysis on return line assembly• Boundary conditions
• System driven by pump replicating return flow curve
• System open at tank end with applied nominal line pressure
• Evaluate pressure waveform at 76Hz resonance• Use as base case for comparisons to proposals
• Determine method to best dampen pressure pulsations• Resonator
• Rubber hose
• Pulse damper
2014 Gamma Technologies North America UGM
Results: Frequency Sweep Analysis
• Frequency sweep pressure contour for 76Hz
2014 Gamma Technologies North America UGM
Results: Frequency Sweep Analysis
Component peak pressures at determined location
2014 Gamma Technologies North America UGM
Model Approach: Frequency Sweep Analysis w/
Rubber Hose
• Perform sweep analysis on return line assembly• Boundary conditions
• Same as frequency sweep analysis
• Replaced portion of existing line with rubber hose
• Evaluate effectiveness of hose to base case
2014 Gamma Technologies North America UGM
Comparison of component peak pressures at determined location
Results: Frequency Sweep Analysis w/
Rubber Hose
2014 Gamma Technologies North America UGM
Conclusions
• Fuel line analysis– Analysis results aligned with physical system
• Determined mechanism of the vibration– Resonance condition
• Trial and error possible solutions to dampen pulsations– Avoid excessive testing on a vehicle
– Rubber hose proposal• Validated with testing
• Moved forward to production in return line design
2014 Gamma Technologies North America UGM
Evaporative Emissions System Flow Analysis
Evaporative Emissions System
• Objective– Replicate full system bench testing used for calibration
• Reduce required testing
• Provide calibration flow map earlier in the vehicle development cycle
• Evaluate flow map shift due to system design change– Support “White Paper” flow map validation
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model: Overview
Canister Purge Valve (CPV)
Carbon Canister
Canister Load Line
Fresh Air Line
Purge Line
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model
• Model considerations– CPV and carbon canister need most consideration
– CPV model • Pulse Width Modulated (PWM) valve
– Controls flow by setting a duty
cycle to voltage signal
» Higher the duty cycle yields higher
flow
– Electro magnetic actuation
– Moving seal armature
– Account for seal armature
movement effects to flow
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model
• Model considerations– Carbon canister
• Stores fuel vapor displaced in fuel tank– Using clean canister – no stored vapor
• Not considering any internal valves
• Account for air/void volumes
• Account for flow restriction due to
carbon bed
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model
• Model correlation– CPV
• Steady state test
• Averaged pressure from
model
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model
• Model correlation– Carbon canister
• Steady state test
• Steady state model
2014 Gamma Technologies North America UGM
Evaporative Emissions System Model
• Model correlation– Evap System
• Steady state test
• Averaged pressure
from model
• Wrong valve used
from test
2014 Gamma Technologies North America UGM
Conclusions
• Evaporative Emissions System Flow Analysis– Good correlation for CPV
• For steady state condition – Reasonably capturing flow effects of moving armature
– Reasonably capturing electromagnetic force applied to armature
– Good correlation for carbon canister• For steady state condition
– Capturing flow restriction due to internal geometric features
– Capturing flow restriction due to the carbon beds
– Promising correlation to evap system testing• Expect that model will correlate with testing
– Update CPV model to the high flow valve
2014 Gamma Technologies North America UGM
Q & A
Thank You