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