Dinex presentation, urea spray development

Development of Multiphase
CFD for Future Exhaust
Systems at Dinex
Presented at DANSIS Automotive Fluid
Dynamics Seminar
25th of March 2015
mlr@dinex.dk
/ ksa@dinex.dk, 25-03-2015
Page 1 of 26
Outline
1.
2.
3.
Introduction
Case studies
Concluding remarks
Kasper Steen Andersen
Martin Larsen
Background
•
M.Sc. Phys. & Tech. 2005
•
9 years at Dinex
Background
•
M.Sc. Energy 2012
•
3 years at Dinex
Current
•
CAE manager, R&D
Current
•
Project Engineer CFD multiphase
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Dinex Group
Exhaust & emission system manufacturer
Employees
Dinex: 1350
R&D: 40
CAE: 10
Trucks – CNG Trucks
Buses – CNG Buses
Construction
Agricultural
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Marine
Trains & locomotives
Large stationary
Motivations
“We need to develop
and validate CAE
based on NAFEMS &
ASME V&V approach”
”Bring simulation
results on a
believable scale”
Customer
•
Simulation
•
•
•
•
Dinex
Meet customer expectations & requirements
Cost price & development time
Performance & knowledge
Urea spray simulations
•
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Predict and improve ammonia distribution and
deposition
CAE Capability Status
Simulation
Analysis type
NVH
Transmission Loss
5
Single phase CFD
4
Multiphase urea spray
2
Modal Analysis
3
Static G-load
3
Forced response
2
Surface temperature
2
Thermal stress
0
CFD
FEA structural
FEA
thermal
NVH = Noise, Vibration & Harshness
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CFD = Computatinal Fluid Dynamics
Maturity (TRL)
FEA = Finite Element Analysis
CAE Capability Goals
Phase 3E
HC spray & DPF
Structural & Thermal
fatigue
Phase 3E
Simulation Development
Phase 3C
Phase 3A
Project description
2014
Page 6 of 26
Substrate TL & TPN
BP & flow UI
Simple urea spray
Static structural & modal
Temp distribution &
simple thermal stress
2015
Shell radiated noise
Urea spray & deposits
Nonlinear static structural
& forced response
FSI & Thermal stress
2016
2017
CAE Development process
Simulation development
Problem
definition
1
2
Verification &
Validation
3
4
Concept
development
Improvement
5
6
GATE:
Simulation
ready for
application
use
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Product development
7
Customer
application
development
8
Overall
phases
Working
phases
9
Technology
Readyness
Levels
GATE:
Design
ready for
application
use
The future exhaust system
Engine out emissions
(particulates & gasses)
NOX
PM
Diesel Oxidation
Catalyst
NOX
HC
CO
PM
Filter with SCR
(Selective Catalytic Reduction)
CO
CFD simulation domain
AdBlue
NOx reductant
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NOX
HC
Trade name for Urea Water Solution (UWS)
Ammonia from the urea in UWS
PM
HC
CO
Scope
- CFD Simulation Domain
SCR system from a CFD perspective. Based on (Fischer, 2014)
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Outline
1.
2.
3.
Page 10 of 26
Introduction
Case studies
Concluding remarks
Case study
•
•
•
Case 1 - Evaporation and decomposition
Case 2 - Spray impingement
Case 3 - Full System
Page 11 of 26
Case 1
- Evaporation and decomposition
Experiment description
•
Experimental conversion efficiency results
(Kim et al., 2004) compared to AVL FIRE
simulations
Model description
•
•
Setup provided by AVL France (AVL, 2015)
AVL FIRE spray module modelling
•
urea-water properties
•
spray-gas interaction
•
evaporation
•
chemical decomposition
Evaporation
Thermolysis
Hydrolysis
Page 12 of 26
𝑈𝑊𝑆(𝑙) → 𝑁𝐻2 2 𝐶𝑂(𝑠
𝑁𝐻2 2 𝐶𝑂(𝑠
𝑙)
𝑙)
Experimental setup (Kim et al., 2004)
(Not to scale)
+ 𝐻2 𝑂(𝑔)
→ 𝑁𝐻3(𝑔) + 𝐻𝑁𝐶𝑂(𝑔)
𝐻𝑁𝐶𝑂(𝑔) + 𝐻2 𝑂(𝑔) → 𝑁𝐻3(𝑔) + 𝐶𝑂2(𝑔)
AVL FIRE visualisation of droplets (top) and NH3(g)
mass fraction (Not to scale)
Case 1
- Evaporation and decomposition
10.8 m/s: correlate well
9.1 m/s: slightly under predicted
6.4 m/s: under predicted
Differences may be due to
- Complex physics
- Only ammonia Exp results
- AVL FIRE setup tuned to
residence times below 0.1s.
AVL FIRE simulation results versus experimental data from
(Kim et al., 2014)
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Case 2
- Spray impingement
Experiment description
•
Experimental steel temperature results
(Birkhold et al., 2006), (Birkhold, 2007)
compared to AVL FIRE simulations
Model description
•
•
Setup provided by AVL France (AVL, 2015)
AVL FIRE modules
Spray
modelling urea-water properties,
spray-gas interaction, evaporation
and chemical decomposition
Wall film
modelling spray-wall interaction
and evaporation and
decomposition from wall film
Thin wall
modelling heat transfer
Experimental setup (Birkhold, 2007)
AVL FIRE visualisation of droplets (black) and steel
plate temperature
Page 14 of 26
Case 2
- Spray impingement
Good correlation for tendency
and final temperature
No wall film
visible wall film
AVL FIRE simulation results versus experimental data from
(Birkhold, 2007)
Differences may be due to
- Limited information on Experimental data
- Complex spray/wall physics
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Reasonable correlation for
tendency and final temperature
Case 3
- Full system
Experiment description
•
Experimental gas distribution and pipe wall
temperature results (Dinex, 2015) compared to
AVL FIRE simulations
Model description
•
•
Setup provided by AVL France (AVL, 2015)
AVL FIRE modules
Porosity
porous media modelling
Spray
modelling urea-water properties,
spray-gas interaction, evaporation
and chemical decomposition
Wall film
modelling spray-wall interaction
and evaporation and
decomposition from wall film
Thin wall
modelling heat transfer
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Experimental setup (Dinex, 2015)
Case 3
- Full system
Distribution of NOx
Experimental setup (Dinex, 2015)
24 gas sampling setup on SCR outlet
(Dinex, 2015)
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Case 3
- Full system – Distribution of gaseous species
Experimental
Model*
Highest value
in top of plot
->
Good
correlation
with Exp
Absolute NOx
values bad
correlation
𝑈𝐼𝑁𝑂𝑥 = 0.84
𝑈𝐼𝑁𝑂𝑥∗ = 0.80
Experimental NOx distribution [ppm] (left) versus approximated NOx*
from AVL FIRE simulation results (right).
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Uniformity
0.04 lower
Differences may be due to
• local data points
• experimental method
• modelling method
Case 3
- Full system - Troubleshooting
Troubleshooting
Wall temperatures was
measured
Page 19 of 26
Case 3
- Full system - Troubleshooting
Troubleshooting - Pipe wall temperatures
Spray visualisation
(blue)
04
03
02
Experimental pipe wall temperature sampling locations
Wall temperatures are an indirect
measure spray behaviour
Cooling of wall =
spray impingement
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01
Case 3
- Full system – Pipe wall temperatures
Experimental
injection start
Model
injection start
Red (01) and green
(02) within 25°C
Cooling
captured
Blue (03) and black (04)
under predicted by 50°C
Differences seen on
temperatures may explain
NOx differences
Experimental pipe wall temperatures (left) versus AVL FIRE simulation
results (right)
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Need to look further into
- Spray data/behaviour
- Heat transfer
Outline
1.
2.
3.
Page 22 of 26
Introduction
Case studies
Concluding remarks
Concluding remarks
Case 1 & 2 – Paper benchmarks
•
Reasonable correlation
Case 3 – Full system
NOx distribution at SCR outlet
•
Overall distribution tendency correct
•
Absolute ppm values not ok
•
Uniformity value not ok
Pipe wall temperatures
•
Cooling tendency correct in 1 case from 3
•
Absolute values within 40-50°C
Page 23 of 26
Next Steps
General
•
•
•
Sensitivity study
Uncertainty analysis
Planning of new Experiments
Specifically
•
•
•
Spray behavior
Heat transfer in steel
Heat loss
SCR systems from a CFD perspective.
Based on (Fischer, 2014)
Page 24 of 26
Bibliography
AVL, 2015. AVL FIRE. [Online]. Available at: https://www.avl.com/fire2
Birkhold, F., 2007. Selektive Katalytische Reduktion von Stickoxiden: Untersuchung der Einspritzung von
Harnstoffwasserlösung, s.l.: Fakultät für Maschinenbau, Universität Karlsruhe. Berichte aus der
Strömungstechnik, Shaker Verlag, Aachen.
Birkhold, F., Meingast, U., Wassermann, P. & Deutschmann, O., 2006. Analysis of the Injection of Urea-WaterSolution for Automotive SCR DeNOx Systems: Modeling of Two-Phase Flow and Spray/WallInteraction. SAE Technical Paper 2006-01-0643.
Dinex, 2015. Engine dyno testing in Dinex test facility. Middelfart: Dinex A/S.
Fischer, S., 2014. Simulation SCR Systems Using STAR-CCM+: Workshop "CFD Simulation for Improving After
Treatment Devices", Nuremberg: CD-adapco.
Kim, J. Y., Ryu, S. H. & Ha, J. S., 2004. Numerical Prediction on the Characteristics of Spray-Induced Mixing and
Thermal Decomposition of Urea Solution in SCR System. Long Beach, California, USA, ASME 2004
Internal Combustion Engine Division Fall Technical Conference.
Page 25 of 26
Thank you for
your attention
Any questions?
Kasper Steen Andersen
CAE manager, R&D, ksa@dinex.dk
Page 26 of 26
Martin Larsen
Project Engineer CFD multiphase, mlr@dinex.dk