Validation and Optimization of Front End Cooling Module for Commercial Vehicle using CFD Simulation
Ashok Patidar, Umashanker Gupta, Nitin Marathe VE Commercial Vehicles Ltd. INDIA
(A VOLVO GROUP AND EICHER MOTORS JOINT VENTURE)
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress
Buses : 12 seater – 65 seater
VE Commercial Vehicles Ltd - Overview
School Buses:
Staff Buses:
City Buses & Special applications:
Trucks : 5 Tons – 40 Tons Haulage: 5 Tons – 31 Tons
Tipper: 8 Tons – 25 Tons
Articulated Tractor: 40 Tons
2
Contents
2012 Automotive Simulation World Congress 3 Wednesday, September 26, 2012
Introduction
Methodology
Results Summery
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Introduction
In CFD modeling full vehicle is modeled considering front bumper, grille, cabin, cargo, surrounding under hood and under body components.
The flow resistance of heat exchangers is considered using porous modeling technique.
Heat exchanger performance data generated from 1-D Kuli software is taken in simulation using single pass Heat Exchanger model.
Front End Cooling analysis is done for max power and max torque vehicle conditions.
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Introduction Preliminary CFD Front End Cooling analysis is done on
existing commercial vehicle and correlated well with field test results.
Front grille Opening Intercooler Radiator
Developed and validated CFD Front End Cooling process is implemented on new commercial Vehicle.
Hot and cold air recirculation zones are identified in under hood compartment. Elimination of recirculation showed good improvement in radiator and intercooler cooling performance.
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Methodology: CFD Simulation CAD Model
CAD Cleanup
Mesh Model Generation
Setup and Solver (solve fundamental equations)
Post Processing and Result Interpretation
Is met the
targets?
Final Proto Test Verification
Using HyperMesh
Using TGrid
Using Fluent
Using CFD Post
Design Change Recommendation No
Yes
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Non conformal mesh technique is used for heat exchanger modeling
Methodology: Mesh Generation
Non conformal Mesh @ Intercooler
Quad Shell @ Intercooler Faces
Tri Shell @ Intercooler tank headers & Hoses
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Non conformal Mesh @ Radiator
Quad Shell @ radiator Faces
Tri Shell @ radiator tank headers & Hoses
Methodology: Mesh Generation
Non conformal mesh technique is used for heat exchanger modeling
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Volume Mesh @ Computational Domain Under-hood components
Methodology: Mesh Generation
Radiator
Intercooler
Radiator Fan
Radiator Tank
Non conformal mesh technique is used for heat exchanger modeling
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Max Power Max Torque Vehicle Speed (KMPH) V1 V2
Radiator Fan Speed (RPM) N1 N2
Vehicle Speed & Fan Speed:
Input Parameters for thermal analysis : Max Power Max Torque
Radiator
Coolant Flow Rate (kg/s) mc1 mc2
Coolant Inlet Temp ( C) Tcin1 Tcin2 Intercooler
Charged air Flow Rate (kg/s) ma1 ma2 Charged air inlet temp ( C) Tain1 Tain2
Note : Owing to IPR policy the numerical values cloud not disclosed
Heat Exchanger Model: • Ungrouped Macro Based Model is used
• Fix inlet temperature
Methodology: Input Conditions
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Heat exchanger performance data generated through 1-D KULI software for computing heat rejection and outlet temperature of coolant and charged air :
Methodology: Input Conditions
Intercooler performance data : charged air flow
rate (kg/s) c1 c2 c3 c4 c5 c6
Air Flow rate (kg/s)
Heat Transfer (W)
a1 h11 h21 h31 h41 h51 h61
a2 h12 h22 h32 h42 h52 h62
a3 h13 h23 h33 h43 h53 h63
a4 h14 h24 h34 h44 h54 h64
a5 h15 h25 h35 h45 h55 h65
a6 h16 h26 h36 h46 h56 h66
Radiator performance data : Coolant flow
rate (kg/s) c1 c2 c3 c4 c5 c6
Air Flow rate (kg/s)
Heat Transfer (W)
a1 h11 h21 h31 h41 h51 h61
a2 h12 h22 h32 h42 h52 h62
a3 h13 h23 h33 h43 h53 h63
a4 h14 h24 h34 h44 h54 h64
a5 h15 h25 h35 h45 h55 h65
a6 h16 h26 h36 h46 h56 h66
Note : Owing to IPR policy the numerical values cloud not disclosed
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Results: Existing Vehicle – Max Power Condition Radiator
Velocity contours (m/s)
Temperature contours ( C)
Velocity = 7.2 m/s
Coolant flow direction
CFD ∆T = 5.5 C
Intercooler Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Velocity = 5.2 m/s
CFD ∆T = 76.5 C Test Coolant ∆T = 4.7 C Test Charged Air ∆T =63.7 C
Charged Air Flow direction
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
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Results: Existing Vehicle – Max Power Condition Radiator
Velocity contours (m/s)
Temperature contours ( C)
Velocity = 7.2 m/s
Coolant flow direction
CFD ∆T = 5.5 C
Intercooler Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Velocity = 5.2 m/s
CFD ∆T = 76.5 C Test Coolant ∆T = 4.7 C Test Charged Air ∆T =63.7 C
Charged Air Flow direction
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
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Predicted vehicle level performance of intercooler and radiator at fixed inlet temp
Correlation: Existing Vehicle – Max Power Condition
Ambient Temp = 28.5 C Intercooler Radiator
Test CFD Correlation
(%) Test CFD
Correlation (%)
Coolant/ Charged air
side
CFD Inputs Flow Rate (kg/s) ma1 ma1 -- mc1 mc1 --
Inlet Temp (°C) Tain1 Tain1 -- Tcin1 Tcin1 --
CFD Outcomes
Outlet Temp (°C) Taout1Test Taout1CFD -- Tcout1Test Tcout1CFD --
Temp Drop (°C) 63.7 76.5 80 4.7 5.5 83
Heat Rejection (kW) 8.3 10 79.5 42.6 49.9 82.8
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Results: Existing Vehicle – Max Torque Condition Radiator
Velocity contours (m/s)
Temperature contours ( C)
Coolant flow direction
Intercooler Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Charged Air Flow direction
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Velocity = 3.1 m/s
CFD ∆T = 5.8 C
Velocity = 2.2 m/s
CFD ∆T = 52.5 C Test Coolant ∆T = 5 C Test Charged Air ∆T =47.3 C
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 16
Results: Existing Vehicle – Max Torque Condition Radiator
Velocity contours (m/s)
Temperature contours ( C)
Coolant flow direction
Intercooler Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Charged Air Flow direction
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Velocity = 3.1 m/s
CFD ∆T = 5.8 C
Velocity = 2.2 m/s
CFD ∆T = 52.5 C Test Coolant ∆T = 5 C Test Charged Air ∆T =47.3 C
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Ambient Temp = 29 C Intercooler Radiator
Test CFD Correlation
(%) Test CFD
Correlation (%)
Coolant/ Charged air
side
CFD Inputs Flow Rate (kg/s) ma2 ma2 -- mc2 mc2 --
Inlet Temp (°C) Tain2 Tain2 -- Tcin2 Tcin2 --
CFD Outcomes
Outlet Temp (°C) Taout2Test Taout2CFD -- Tcout2Test Tcout2CFD --
Temp Drop (°C) 47.3 52.5 89 5 5.8 84
Heat Rejection (kW) 3.1 3.4 90.3 20.1 23.4 83.6
Predicted vehicle level performance of intercooler and radiator at fixed inlet temp
Correlation: Existing Vehicle – Max Torque Condition
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New Vehicle – Geometry Details
Intercooler – Radiator -Fan Module (IRFM)
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Hot air recirculation in front of intercooler
Hot air recirculation in front of intercooler
Path Lines coloured by Temperature ( C)
Results: New Vehicle – Under-hood Thermal Flow Field
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 20
Hot air recirculation in front of intercooler
Hot air recirculation in front of intercooler
Path Lines coloured by Temperature ( C)
Results: New Vehicle – Under-hood Thermal Flow Field
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Results: New Vehicle – Baseline IRFM Packaging
Intercooler – Radiator –Fan Module
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Results: New Vehicle –Improved IRFM Packaging
Intercooler – Radiator –Fan Module
IRFM Sealing
introduced IRFM Sealing to stop hot air recirculation in under-hood compartment as shown in above fig.
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Hot air recirculation in front of intercooler
Path Lines coloured by Temperature ( C)
Results: New Vehicle – Under-hood Thermal Flow Field Baseline – IRFM Packaging Improved – IRFM Packaging
No hot air recirculation in front of intercooler
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Velocity contours (m/s)
Temperature contours ( C)
Velocity = 5.2 m/s
CFD ∆T = 78.5 C
Intercooler
Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Velocity = 5.2 m/s
CFD ∆T = 70.1 C
Charged Air Flow direction
Results: New Vehicle – Max Power Condition
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Intercooler
Charged Air Flow direction
Improved ambient air temperature profile at the intercooler inlet face
Baseline – IRFM Packaging Improved – IRFM Packaging
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 25
Velocity contours (m/s)
Temperature contours ( C)
Velocity = 5.2 m/s
CFD ∆T = 78.5 C
Intercooler
Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Velocity = 5.2 m/s
CFD ∆T = 70.1 C
Charged Air Flow direction
Results: New Vehicle – Max Power Condition
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Intercooler
Charged Air Flow direction
Improved ambient air temperature profile at the intercooler inlet face
Baseline – IRFM Packaging Improved – IRFM Packaging
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 26
Velocity contours (m/s)
Temperature contours ( C)
Radiator
Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Results: New Vehicle – Max Power Condition
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Radiator
Baseline – IRFM Packaging Improved – IRFM Packaging
Velocity = 7.3 m/s
CFD ∆T = 6.4 C
Velocity =7.3 m/s
CFD ∆T = 5.9 C
Coolant flow direction Coolant flow direction
Improved ambient air temperature profile at the Radiator inlet face
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 27
Velocity contours (m/s)
Temperature contours ( C)
Radiator
Velocity contours (m/s)
Temperature contours ( C)
Inlet Face Outlet Face
Results: New Vehicle – Max Power Condition
Min
Max
Min
Max
Min
Max
Min
Max
Inlet Face Outlet Face
Radiator
Baseline – IRFM Packaging Improved – IRFM Packaging
Velocity = 7.3 m/s
CFD ∆T = 6.4 C
Velocity =7.3 m/s
CFD ∆T = 5.9 C
Coolant flow direction Coolant flow direction
Improved ambient air temperature profile at the Radiator inlet face
Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 28
Summery
Correlation level between Field test and CFD simulation is more than 80%
Hot air recirculation has been identified for new vehicle
under-hood compartment using validated CFD process Under-hood compartment thermal flow field has been
improved by stooping hot air recirculation by introducing sealing, thus improved : 12% Intercooler performance & 8.5% Radiator performance
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THANK YOU !!
Contact:
Ashok Patidar