modeling of a new generation solenoid common rail injector · pdf file17-10-2016 andrea piano...

17-10-2016

Andrea PIANO, Federico MILLO

Politecnico di Torino

Lucio POSTRIOTI, Andrea CAVICCHI, Giulia BISCONTINI

Università degli Studi di Perugia

Francesco C. PESCE

General Motors – Global Propulsion System

Modeling of a New Generation

Solenoid Common Rail Injector European GT Conference 2016 - Frankfurt

17-10-2016 Andrea PIANO - Modeling of a new generation solenoid Common Rail injector

European GT Conference – Frankfurt 2016

Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions



Common Rail FIS

The more and more stringent emission requirements along with the more demanding targets for fuel consumption reduction, are calling for enhanced fuel injection systems for diesel engines.

4

Increased number of inj pulses (up to 12)

Increased inj pressure levels (up to 3000 bar)

Reduced dwell time between injections

Injection rate shaping

Large varieties of

systems with deep

specialization

Coupling between

different physical

domains

Wide range of

pressures

Main challanges for numerical simulation of FIS

Source: http://www.dieselnet.com



FIS Numerical Simulation Different approaches for the simulation of the injection systems:

3D-CFD – Focuses on detailed simulation of fluid domain.

1D-CFD – Navier-Stokes, Newton and Maxwell equations are computed to

model fluid, mechanical and electromagnetic parts using a 1D reduction.

Bond Graph –Network of 0D elements. This 0D schematization produces only

ODEs and DAEs.

5

1. Multi-domain (differently from 3D-CFD)

2. Physically based representation of phenomena

(differently from Bond Graph)

3. Coupling with predictive combustion model DIPulse



Agenda

Introduction

Experimental Setup

Test Matrix


Conclusions



Experimental Facilities In order to build a 1D-CFD model of a Common Rail injector, 2 crucial issues need to

be addressed:

7

Source: http://www.boschautoparts.com

Internal

geometry

detection

Extensive

dataset of

experimental

injection rate

1. Piano, A., Millo, F., Postrioti, L., Biscontini, G. et al., "Numerical and Experimental Assessment of a Solenoid Common-Rail Injector Operation with Advanced Injection Strategies," SAE

Int. J. Engines 9(1):565-575, 2016, doi:10.4271/2016-01-0563.



STS Injection Analyzer For injection rates measurements, an STS Injection Analyzer, based on the Zeuch

method, was used.

8

It consists of:

Injection in a close, fixed-volume chamber

filled with the same injected fluid

Pressure as primary measurement

∆𝑃 =𝑘

𝑉∆𝑉

Injection rate evaluation by differentiating

the pressure equation

𝑄 =𝑑𝑉

𝑑𝑡=𝑉

𝑘

𝑑𝑃

𝑑𝑡

1. L. Postrioti, G. Buitoni, F. C. Pesce, C. Ciaravino, Zeuch method-based injection rate analysis of a common-

rail system operated with advanced injection strategies, Fuel, Volume 128, 15 July 2014, Pages 188-198,

ISSN 0016-2361, http://dx.doi.org/10.1016/j.fuel.2014.03.006.

2. L. Postrioti, S. Malaguti, M. Bosi, G. Buitoni, S. Piccinini, G. Bagli, Experimental and numerical

characterization of a direct solenoid actuation injector for Diesel engine applications, Fuel, Volume 118, 15

February 2014, Pages 316-328, ISSN 0016-2361, http://dx.doi.org/10.1016/j.fuel.2013.11.001.

V, P V, P+

Test fluid

V, P V,

P+ dP

dV

Injector

Inj

Rate

– N

eedle

lif

t

Time

IR Needle Lift



Agenda

Introduction

Experimental Setup

Test Matrix


Conclusions



Test Matrix Selection

10

Element Holes Nominal diameter Flow number

[-] [number] [mm] [cc/30s @∆p = 100 bar]

Nozzle #1 7 0.139 390

Nozzle #2 8 0.114 340

Single Injection Test

Nozzle #1

Nozzle #2

0

200

400

600

800

1000

1200

1400

0 200 400 600 800 1000 1200

Rail P

ress

ure

[bar]

Energizing Time [ms]

Energizing Time



Test Matrix – Engine Patterns

11

950 bar

700 bar

1050 bar

800 bar

850 bar

1000 bar

Typical Engine Injection Pattern Test

Nozzle #2

1500 rpm X 2 bar

𝑄1500𝑟𝑝𝑚 ≅ 7𝑚𝑚3

𝑠𝑡𝑟

2000 rpm X 8 bar

𝑄2000𝑟𝑝𝑚 ≅ 24𝑚𝑚3

𝑠𝑡𝑟

430 bar

360 bar

400 bar

370 bar

550 bar

460 bar



Test Matrix – Innovative

12

Innovative Injection Pattern Test

Nozzle #1

Hydraulic Fusion with Single and Double Pilot

MultiPilot events + After Injections

RailP = 400 bar

RailP = 1000 bar

RailP = 400 bar

RailP = 1000 bar

RailP = 400 bar

RailP = 1000 bar

RailP = 400 bar

RailP = 1000 bar



Agenda

Introduction

Experimental Setup

Test Matrix


Conclusions



Results – Single Injection

14

Injection Rate comparison

Nozzle #1

Nozzle #2

800 bar 600 bar

400 bar 600 bar



Results – Single Injection Nozzle #2 – Total Injected Volume comparison

15

y = 1.10 x

R2 = 0.99

y = 1.04 x

R2 = 0.99

y = 0.98 x

R2 = 0.99

y = 0.94 x

R2 = 0.99

y = 0.95 x

R2 = 0.99

y = 0.94 x

R2 = 0.99

Rail Pressure = 300 bar



Rail Pressure = 1000 bar Rail Pressure = 1200 bar




Results – Engine Patterns

16

Instantaneous injection rate profiles comparison for 2000 rpm X 8 bar operating

condition:

The 1D-CFD injector model is able to predict the injection rate with the correct

timing and also the pulse to pulse interaction for a conventional injection

strategies in a modern light duty diesel engine

700 bar 800 bar 1000 bar



Results – Hydraulic Fusion

17

Nozzle #1 – Injection Rate comparison

Single Pilot

Double Pilot



Results – MultiPilot

18

Nozzle #1 – Injection Rate comparison

With After



Agenda

Introduction

Experimental Setup

Test Matrix


Conclusions



Conclusions

20

A methodology for obtaining a complete characterization of a solenoid ballistic injector for a Light-Duty Common Rail diesel engine in GT-SUITE was presented

In literature it is possible to find different approaches for obtaining an accurate detection of the internal geometry

An extensive dataset of experimental measurements was used in order to validate the model. The injection rate profiles have been measured by means of STS Injection Analyzer based on Zeuch’s Method

In order to assess the predictive capabilities of the model, 2 different nozzles were tested and simulated for several single and multi-event operation strategies

The comparison between the experimental and simulated injection rates profiles showed a more than satisfactory accuracy of the model both for single and multiple injection events pattern



Injector Model + DIPulse

21

Burn rate and NOx emissions comparison

1500x2 1500x5 1500x8 2000x2 2000x5 2000x8 2000x12

NO

x E

mis

sions

[-]

Engine operating point [rpm x bmep]

NOx Emissions

Experimental Simulated



Virtual Test Rig in GT-SUITE

22



Virtual Test Rig in GT-SUITE

23

Injector Current Profile

DIPulse Predictive

Combustion model

BSNOx - BSFC CN - BSFC

17-10-2016

Andrea PIANO, Federico MILLO

Politecnico di Torino

Lucio POSTRIOTI, Andrea CAVICCHI, Giulia BISCONTINI

Università degli Studi di Perugia

Francesco C. PESCE

General Motors – Global Propulsion System

Modeling of a New Generation

Solenoid Common Rail Injector European GT Conference 2016 - Frankfurt

modeling of a new generation solenoid common rail injector · pdf file17-10-2016 andrea piano...

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