Improving Environmental T echniques of Controlling I nvasive W eeds
A DVANCED S IMULATION T ECHNIQUES FOR IC E NGINES 1.
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Transcript of A DVANCED S IMULATION T ECHNIQUES FOR IC E NGINES 1.
1
ADVANCED SIMULATION TECHNIQUES FOR IC ENGINES
ASTICE
2
APPLICATION
• Hydraulic System simulation
• Control System Analysis
• Map Based simulation
• 1D general Flow Analysis- utility design
• CFD- 3D Combustion and Emission analysis
Engine Cycle
Simulation
Cooling circuit
simulation
Fuel Injection System Analysis
Driveline Simulation
CFD- 3D Compressible flow analysis
CFD- 3D general flow analysis
3
ENGINE CYCLE SIMULATION
Combustion
Model
• Weibe function Model • Multi-zone spray Model • Two-Zone knock model for SI and DF engine
Gas exchange Mode
l
• 1D gas dynamic model• Turbocharger Matching
Optimization
Model
• RSM model with DOE• Optimization Using Genetic Algorithm
4
ENGINE CYCLE SIMULATION-CASE 1
Fit Weibe functio
n
Generate Model
Single Cylinde
r
Complete Engine
Cycle
Run the model
Weibe combustion model
5
ENGINE CYCLE SIMULATION-CASE 1
Fit Weibe function to experimental or CFD
heat release
Single DI Weibe Start of combustionCrank angle at 1% burned
Combustion Duration & Weibe exponentCalculated by non-linear least square method
Multiple DI Weibe Start of combustionCrank angle at 0.5% burned
Premixed fraction, Premixed combustion duration , premixed Weibe exponent, mixing controlled combustion duration and mixing
controlled Weibe exponentCalculated by non-linear least square method
Weibe combustion model
ENGINE CYCLE SIMULATION-CASE 1
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Single Weibe ModelSOC = -5.3Θd = 63.5M = 0.96
Multiple Weibe ModelSOC = -4.1Pf = 0.1Θd_p = 12Mp = 0.5Θd_p = 60Mp = 1.15
Weibe combustion model Fit Weibe function
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ENGINE CYCLE SIMULATION-CASE 1
Model Generation
•Single Cylinder Model•Complete Engine Cycle
Weibe combustion model Model Generation
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ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model Generation Single cylinder Model
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ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model Generation Single cylinder Model
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ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model Generation Single cylinder Model
Zoom
Single Cylinder results
11
ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model Generation Single cylinder Model
Single Cylinder results
Scav
engi
ng
12
ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model Generation Single cylinder Model
Single Cylinder results
Indicated Power 99.6 kW
•IMEP=25 bar•Indicated Efficiency= 50.6%
Heat transfer to walls19.6 kW
•6.7 kW from Gas to Liner•6.4 kW from Gas to Head•6.5 kW from Gas to Piston
Exhaust Energy77.6 kW
•A fraction is recovered through turbocharger in multi cylinder engine
Fuel Energy
196.8 kW
13
ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model GenerationComplete Engine
Cycle
Single Cylinder Model
Firing Order/ No. Cylinders
TC and ICmodel
Filling & Emptying Model
Friction Model
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ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model GenerationComplete Engine
Cycle
Filling & Emptying Model
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ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model GenerationComplete Engine
Cycle
Filling & Emptying Results
Gas Exchange Diagram
16
ENGINE CYCLE SIMULATION-CASE 1Weibe combustion
model Model GenerationComplete Engine
Cycle
Filling & Emptying Model Results
Ambient Temp (°C) 25
I/C Water Temp (°C) 33
Power (kWb) 500
Speed (r/min) 1500
BMEP (bar) 21
BSFC (g/kWh) 199
BSAC (kg/kWh) 6.56
Firing Pressure (bar) 170
Boost Pressure Ratio 3.05
Compressor Exit Temp (°C) 171
Air Manifold Temp (°C) 48
Compressor Eff. (%) 76
Turbocharger Eff. (%) 58.5
Surge Margin (%) 26
Exh M’fold Temp Energy Mean (%) 516
Turbine Inlet Temp (Estimated) (°C) 575
Trapped A/F Ratio 25.5:1
Compressor Raw Map
Turbine Raw Map
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ENGINE CYCLE SIMULATION-CASE 2
Multi-zone spray Model for Diesel combustion
More info: SAE paper No. 2001-01-1246
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ENGINE CYCLE SIMULATION-CASE 2
Main code
Discharge Coefficient Routine
Spray Penetration Routine
Droplet Evaporation Routine
Sauter Mean Diameter Routine
Air Entrainment Routine
Heat transfer Routine
Multi-zone spray Model for Diesel combustion
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ENGINE CYCLE SIMULATION-CASE 2Multi-zone spray Model for Diesel combustion
Start of Combustion Premixed combustion
Temperature Distribution in Spray Zones
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ENGINE CYCLE SIMULATION-CASE 2Multi-zone spray Model for Diesel combustion
Peak heat release rate
Temperature Distribution in Spray Zones
Combustion tale
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ENGINE CYCLE SIMULATION-CASE 2Multi-zone spray Model for Diesel combustion
Fuel evaporation & Burn NOx & SOOT
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ENGINE CYCLE SIMULATION-CASE 2Multi-zone spray Model for Diesel combustion
Pressure & Temperature Normalized Fuel Injection, Evaporation, Burn and Heat release rate
23
ENGINE CYCLE SIMULATION-CASE 3
Two-Zone knock model for SI and DF engine
The pilot fuel (DF)/Spark (SI) is considered as ignition initiator
The heat released via diesel fuel is entered to model as Weibe
function in DF engines
The ignition delay is calculated from Arrhenius formula
The air and natural gas mixture will be divided into two zones as
soon as combustion starts
The burned zone consists of reacting species and combustion
products.
It is assumed that all of species are in thermodynamic equilibrium
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ENGINE CYCLE SIMULATION-CASE 3
Two-Zone knock model for SI and DF engine
O O2
N2
OH
H2O
H
CO
CO2
H2
Thermodynamic Equilibrium
Heat Release
The Burned Zone
O2OH
H2O
H
CO
Chemical Kinetics
Auto-ignition Knock
The Unburned Zone
CH4HO2
CH3H2O2
CH2O
CHO
N2
25
ENGINE CYCLE SIMULATION-CASE 3
Two-Zone knock model for SI and DF engine
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ENGINE CYCLE SIMULATION-CASE 3
Two-Zone knock model for SI and DF engine
Model Validation
Continuous lines : Two-Zone model resultsPoints : CAT Engine simulation results (SAE paper)
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ENGINE CYCLE SIMULATION- CASE 4
1D gas dynamic model
Significant error
at high speeds
Instability at
low speeds and load
Gas Dynami
c modeli
ng
Filling & Emptying Modeling
1D CFD
Complex program
Better Results
28
ENGINE CYCLE SIMULATION- CASE 4
1D gas dynamic model
Two-Step lax-Wendroff method
Flow Limit Function
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ENGINE CYCLE SIMULATION- CASE 41D gas dynamic model
30
ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching
Marine ManeuveringRail Traction Load acceptance
Steady State Condition
• High efficiency
• Stable Conditions
Criteria for turbo matching
31
ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
Load Increase Process
32
ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
150 Sec Ramp of Throttle from 0-100-Transient Response
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ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
150 Sec Ramp of Throttle from 0-100-Transient Response
34
ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
40 Sec Ramp of Throttle from 0-100-Transient Response
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ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
40 Sec Ramp of Throttle from 0-100-Transient Response
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ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
12 Sec Ramp of Throttle from 0-100-Transient Response
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ENGINE CYCLE SIMULATION- CASE 5 Turbocharger Matching/ Transient operation
12 Sec Ramp of Throttle from 0-100-Transient Response
38
OPTIMIZATION PROCESS Design of Experiments
Results Processed at Polynomial Surfaces
Optimization via Genetic Algorithm
RS
M
Meth
od
olo
gy
39
OPTIMIZATION MODEL- RSM Mathematical and statistical technique for empirical model building
The objective is to optimize a response
changes in the input variables identifies the changes in the output response
The RSM is used to design optimization is reducing the cost of expensive methods
The Approximation model function is generally polynomial
40
OPTIMIZATION MODEL- DOE
An experiment is a series of tests or simulations, called runs
The objective of DOE is the selection of the points where the response should be evaluated
Optimal design of experiments are associated with the mathematical model of the process
The choice of the design of experiments have an influence on the accuracy of the approximation
41
OPTIMIZATION MODEL- DOE METHODS
Box and Dropper
Latin Hypercube
D-Optimum
Full Factorial
Incr
ease
in L
evel of
Acc
ura
cy
Incr
ease
in R
un t
ime
42
OPTIMIZATION EXAMPLE 1Injection timing VS Speed & fuel amount
Response Surfaces
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OPTIMIZATION EXAMPLE 1Injection timing VS Speed & fuel amount
Optimized Map
44
COOLING CIRCUIT SIMULATION
1D CFD analysis of Flow
Simple and Extended model of Heat
exchanger
Coupled Solution with Engine Cycle Simulation
Transient Simulation
Extended Model of Water pump
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COOLING CIRCUIT SIMULATION-CASE 1
Simple and Extended model of Heat exchanger Simple Model
Inside HX•Volume of Fluid•Pressure drop across HX
Effectiveness of HX
•Outside flow rate•Outside temperatre
46
COOLING CIRCUIT SIMULATION-CASE 1
Simple and Extended model of Heat exchanger Extended Model
Inside Flow•Volume of Fluid•Pressure drop across HX•Flow rate•Nu correlation
Outside Flow•Volume of Fluid•Pressure drop across HX•Flow rate•Nu correlation•Effectiveness type
Wall Absorb •Wall material spec•Wall volume
47
COOLING CIRCUIT SIMULATION-CASE 1
Simple and Extended model of Heat exchanger
Simple Model
•Acceptable results for cross flow HXs•Reliable for air cooled radiators and condenser
Extended Model
•More accurate model•Rely on experimental data
48
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Engine
Model
Cooling Circuit Model
Heat Rejection
Heat transfer BCs
49
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Operation of the engine
50
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Operation of the engine
51
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Thermal Results- Coolant inside head drillings
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COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Thermal Results- Coolant inside Cylinder jackets
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COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Thermal Results- HTC Coolant to liner
54
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Thermal Results- average Liner wall temperatureCoolant Side
55
COOLING CIRCUIT SIMULATION-CASE 2
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
Transient Thermal Results- HTC Coolant to head
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COOLING CIRCUIT SIMULATION-CASE 2
Transient Thermal Results- average In-Cylinder Gas temperature
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
To head To Liner- Top
To Liner- Bottom
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COOLING CIRCUIT SIMULATION-CASE 2
Transient Thermal Results- average In-Cylinder HTC
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
To headTo Liner- Top
To Liner- Bottom
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COOLING CIRCUIT SIMULATION-CASE 2
Correlated Thermal Results- average In-Cylinder HTC
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
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COOLING CIRCUIT SIMULATION-CASE 2
Correlated Thermal Results- average In-Cylinder HTC
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
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COOLING CIRCUIT SIMULATION-CASE 2
Correlated Thermal Results- average In-Cylinder HTC
Coupled Solution with Engine Cycle Simulation/ Transient/ Extended pump model
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1D GENERAL FLOW ANALYSIS- UTILITY DESIGN
Combined Heat & Power Generation
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CONTROL SYSTEM ANALYSIS-CASE 1
Waste-gate Control
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CONTROL SYSTEM ANALYSIS-CASE 2
Throttle Control
64
DRIVELINE (MAP BASED) SIMULATION
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DRIVELINE (MAP BASED) SIMULATION
66
DRIVELINE (MAP BASED) SIMULATION-EXAMPLE
UIC Performance test simulation
67
CFD- 3D GENERAL FLOW ANALYSIS
3D Flow Through oil jet
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CFD- 3D GENERAL FLOW ANALYSIS
2D flow through gas throttle Valve
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CFD- 3D GENERAL FLOW ANALYSIS
2D flow through gas throttle Valve
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CFD- 3D GENERAL FLOW ANALYSIS
2D flow through gas throttle Valve
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CFD- 3D GENERAL FLOW ANALYSIS
2D flow through gas throttle Valve
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Flow through Modular Pulse Convertor Exhaust
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Flow through Modular Pulse Convertor Exhaust
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Flow through Modular Pulse Convertor Exhaust
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Flow through Modular Pulse Convertor Exhaust
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Flow through Modular Pulse Convertor Exhaust
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Simulation of paddle wheel test
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CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Simulation of paddle wheel test
79
CFD- 3D COMPRESSIBLE FLOW ANALYSIS
Simulation of paddle wheel test
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CFD- 3D COMBUSTION AND EMISSION ANALYSIS DI Diesel combustion Analysis-Temperature
distribution K
350° CA
364° CA
374° CA