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


• 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


• 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


• 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


Diesel Fuel System Overview

High Pressure Injection Pump

Fuel return line (supply line not shown)

Fuel cooler

Fuel injection

common rail

Fuel tank connection


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


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


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


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



• Pressure contour plot @ 76Hz



• Max pressure pulse location



• Pressure waveform through return line @ 76Hz


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


Results: Frequency Sweep Analysis

• Frequency sweep pressure contour for 76Hz


Results: Frequency Sweep Analysis

Component peak pressures at determined location


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


Comparison of component peak pressures at determined location

Results: Frequency Sweep Analysis w/

Rubber Hose


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


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


Evaporative Emissions System Model: Overview

Canister Purge Valve (CPV)

Carbon Canister

Canister Load Line

Fresh Air Line

Purge Line


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



• 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



• Model correlation– CPV

• Steady state test

• Averaged pressure from

model



• Model correlation– Carbon canister


• Steady state model



• Model correlation– Evap System


• Averaged pressure

from model

• Wrong valve used

from test


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


Q & A

Thank You

Fuel Line Acoustic Nonlinear Analysis ... - Gamma Technologies€¦ · 2014 Gamma Technologies...

Documents

Transcript of Fuel Line Acoustic Nonlinear Analysis ... - Gamma Technologies€¦ · 2014 Gamma Technologies...