analytics based design & development from baseline high ... · title december 15, 2017...
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Title
December 15, 2017
Analytics based design & development from baseline high energy density engine
Nitin Chauhan, Manish Shrivastava, Vivek Apte, Vamshi Krishna Tata Motors Limited,Pune, India
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Nitin ChauhanSenior Manager - Engine Thermodynamic Simulation,Power Systems Engineering,Engineering Research Center,Tata Motors, Pune, India
Manish ShrivastavaDeputy General Manager – Engine SimulationsPower Systems Engineering,Engineering Research Center,Tata Motors, Pune, India
Vivek ApteGeneral Manager – Heavy Duty Diesel EnginesPower Systems Engineering,Engineering Research Center,Tata Motors, Pune, India
Vamshi Krishna Senior Manager (Former Employee)Power Systems Engineering,Engineering Research Center,Tata Motors, Pune, India
Authors
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Engine Hardware Constraint
Design Constraint Diagram
VHED Engine Design: Challenges & Constraints
Material Pressure & Temperature Limits
Peak firing pressure (PFP) ≤ 𝑃𝑚𝑎𝑡
Exhaust temperature ≤ 𝑇𝑚𝑎𝑡
Exhaust Pressure (EP) ≤ EPmax
Performance target
Cold start (Compression ratio (CR) > CRmin)
Performance at very high altitude
Very High Power & Torque
Engine Hardware Constraint
Keep major components as Block, Head, Crankshaft ... same as baseline HED Engine
Same swept volume as of HED engine
Same Common Rail setup
Engine Hardware Alteration (required to manage challenges and constraints)
Injector
Piston Bowl
Turbocharger
Cooling System
Lubrication System
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Design methodology: Scaling-Up Approach
Inferences: to achieve design criteria from scaled up approach for VHED Engine
1. Reduce air flow rate (Reduce Boosting Pressure)
2. Reduce Compression Ratio
Air flow rate Increased in same proportion as BMEP (Power)
High BMEP Very High BMEP 1.6x
ሶ𝑚𝑎𝑖𝑟 kg/h 1.6 ሶ𝑚𝑎𝑖𝑟kg/h 1.6x
𝑷𝒎𝒂𝒕 limit
Conditional Motoring P - θ for VHED Engine with CR same as baseline HED Engine
1.2 𝑷𝒎𝒂𝒕
0.8 𝑷𝒎𝒂𝒕
Scaling-up Air Flow Rate in proportion to Brake Mean Effective Pressure (BMEP) up-scaling
Conditional Motoring (without combustion) P-Theta Curve with ሶ𝒎𝒂𝒊𝒓|𝒎𝒐𝒕𝒐𝒓𝒊𝒏𝒈 = ሶ𝒎𝒂𝒊𝒓|𝒓𝒂𝒕𝒆𝒅 𝒑𝒐𝒘𝒆𝒓
Ruled-out the simplest approach
Baseline HED Engine New VHED Engine
— VHED with π CR— HED with π CR
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Design Methodology: Advanced approach
1D Simulation Close cycle Simulation for Burn Rate Profile
Burn Rate Profile
3D CFD Star ES-ICE In-Cylinder Simulation (Closed Cycle)
Output
Texh < Tmat
Pexh < Psealing
Input(Geometry & Design
parameters)
1D GT-Power Engine Thermodynamic Simulation
Alter Fuel Mass
Torque = (Torque)Target
𝑃𝑚𝑎𝑥 ≤ 𝑃𝑚𝑎𝑡Alter Start of
Combustion (SOC) Angle
Alter Boosting
Triger Parameters
Measures
Tools & Process
Input / Output
Pmax ≤ Pmat
Conditional Motoring Simulation
Combustion Simulation
Air flow rate, Fuel flow rate, SOC (Injection Profile)
Is work done in-3D ≈ work done in 1D for same crank angle ?
Alter Compression Ratio
Is DOE Cycle End?
TOOLS Used for Modeling1D Modeling : GT-POWER3D In-Cylinder : STAR-CD
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1D Thermodynamic Model: Representative View
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Observations: P - θ Plot
𝑷𝒎𝒂𝒕
VHED with 0.89π CR
HED with π CR
𝑷𝒎𝒂𝒕
𝑷𝒎𝒂𝒕
Observation: Peak firing pressure for rated power and torque condition is within material limit.
VHED with 0.89π CR
HED with π CR
VHED with 0.89π CR
HED with π CR
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Observation: Exhaust temperature of VHED engine increased by ~80°C as compare to HED still keeping it below material limit.
Lower RPM Rated Torque Rated Power
VHED with 0.89π CR
HED with π CR
Lower RPM Rated Torque Rated Power
VHED with 0.89π CR
HED with π CR
𝑻𝒎𝒂𝒕
Observations: Temperature and BSFC Plots
VHED with 0.89π CR
HED with π CR
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Injection profile and droplet break up baseline model calibrated to match P-theta
Calibration Variation (ФCFD- ФTest)/ФCFD [%]
Indicated Work around Combustion Phase ( -10 TDC – EVO) 0.5
Peak Pressure [bar] 0.1
Head
Liner
Piston
Sector angle = 45ᵒ
3D CFD In-cylinder Model: Representative view with analytics observation
Representational 3D CFD Model
-200 -150 -100 -50 0 50 100 150 200
Pre
ssu
re
Crank Angle
P-Theta Plots for testing and CFD
Baseline HED engine Testing
Baseline HED engine CFD
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Conclusions
Achieved the Designed Target Conditions
Attained the Peak firing pressure for rated power and torque condition within material limit
Realized Exhaust temperature of VHED engine below material limit
Developed VHED engine without much alteration in baseline HED engine hardware
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