Modeling of a New Generation
Solenoid Common Rail Injector
European GT Conference 2016 - Frankfurt
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
17-10-2016
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
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.

Increased number of inj pulses (up to 12)

Increased inj pressure levels (up to 3000 bar)

Reduced dwell time between injections

Injection rate shaping
Source: http://www.dieselnet.com
Large varieties of
systems with deep
specialization
Wide range of
pressures
Coupling between
different physical
domains
Main challanges for numerical simulation of FIS
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
4
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.
1.
Multi-domain (differently from 3D-CFD)
2.
Physically based representation of phenomena
(differently from Bond Graph)
3.
Coupling with predictive combustion model DIPulse
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
5
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
Experimental Facilities
In order to build a 1D-CFD model of a Common Rail injector, 2 crucial issues need to
be addressed:
Internal
geometry
detection
Extensive
dataset of
experimental
injection rate
Source: http://www.boschautoparts.com
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.
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
7
STS Injection Analyzer
For injection rates measurements, an STS Injection Analyzer, based on the Zeuch
method, was used.
It consists of:
Test fluid


Injector
Injection in a close, fixed-volume chamber
filled with the same injected fluid
dV
Pressure as primary measurement
𝑘
∆𝑃 = ∆𝑉
𝑉
Injection rate evaluation by differentiating
the pressure equation
𝑄=
𝑑𝑉 𝑉 𝑑𝑃
=
𝑑𝑡 𝑘 𝑑𝑡
1. L. Postrioti, G. Buitoni, F. C. Pesce, C. Ciaravino, Zeuch method-based injection rate analysis of a commonrail 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.
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
IR
Needle Lift
Inj Rate – Needle lift

V,V, P+
P+ dP
V, V,
PP
Time
17-10-2016
8
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
Test Matrix Selection
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
1400
 Nozzle #1
1200
Rail Pressure [bar]
 Nozzle #2
Energizing Time
1000
800
600
400
200
0
0
200
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
400
600
800
Energizing Time [ms]
17-10-2016
1000
1200
10
Test Matrix – Engine Patterns
Typical Engine Injection Pattern Test

Nozzle #2


1500 rpm X 2 bar
2000 rpm X 8 bar
1000 bar
460 bar
850 bar
550 bar
1050 bar
370 bar
400 bar
800 bar
360 bar
700 bar
950 bar
430 bar
𝑄1500𝑟𝑝𝑚 ≅ 7 𝑚𝑚
3
𝑠𝑡𝑟
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
𝑄2000𝑟𝑝𝑚 ≅ 24 𝑚𝑚
17-10-2016
3
𝑠𝑡𝑟
11
Test Matrix – Innovative
Innovative Injection Pattern Test

Nozzle #1
Hydraulic Fusion with Single and Double Pilot
RailP = 400 bar
RailP = 1000 bar
RailP = 400 bar
RailP = 1000 bar
MultiPilot events + After Injections
RailP = 400 bar
RailP = 1000 bar
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
RailP = 400 bar
RailP = 1000 bar
17-10-2016
12
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
Results – Single Injection

Injection Rate comparison
Nozzle #1
400 bar
600 bar
600 bar
800 bar
Nozzle #2
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
14
Results – Single Injection

Nozzle #2 – Total Injected Volume comparison
Rail Pressure = 300 bar
y = 1.10 x
R2 = 0.99
Rail Pressure = 800 bar
y = 0.94 x
R2 = 0.99
Rail Pressure = 400 bar
Rail Pressure = 600 bar
y = 1.04 x
R2 = 0.99
Rail Pressure = 1000 bar
y = 0.98 x
R2 = 0.99
Rail Pressure = 1200 bar
y = 0.95 x
R2 = 0.99
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
y = 0.94 x
R2 = 0.99
17-10-2016
15
Results – Engine Patterns
Instantaneous injection rate profiles comparison for 2000 rpm X 8 bar operating
condition:
700 bar
800 bar
1000 bar
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
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
16
Results – Hydraulic Fusion

Nozzle #1 – Injection Rate comparison
Single Pilot
Double Pilot
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
17
Results – MultiPilot

Nozzle #1 – Injection Rate comparison
With After
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
18
Agenda

Introduction

Experimental Setup

Test Matrix

Injection Rate Results

Conclusions
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
Conclusions

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
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
20
Injector Model + DIPulse
Burn rate and NOx emissions comparison
NOx Emissions
Simulated
NOx Emissions [-]
Experimental
1500x2 1500x5 1500x8 2000x2 2000x5 2000x8 2000x12
Engine operating point [rpm x bmep]
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
21
Virtual Test Rig in GT-SUITE
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
17-10-2016
22
Virtual Test Rig in GT-SUITE
Injector Current Profile
DIPulse Predictive
Combustion model
BSNOx - BSFC
Andrea PIANO - Modeling of a new generation solenoid Common Rail injector
European GT Conference – Frankfurt 2016
CN - BSFC
17-10-2016
23
Modeling of a New Generation
Solenoid Common Rail Injector
European GT Conference 2016 - Frankfurt
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
17-10-2016