validation and optimization of front end cooling module for commercial vehicle … ·...

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

Wednesday, September 26, 2012 2012 Automotive Simulation World Congress 4

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.


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.


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


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


Non conformal Mesh @ Radiator

Quad Shell @ radiator Faces

Tri Shell @ radiator tank headers & Hoses




Volume Mesh @ Computational Domain Under-hood components


Radiator

Intercooler

Radiator Fan

Radiator Tank



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


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


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)


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



Results: Existing Vehicle – Max Power Condition Radiator



Velocity = 7.2 m/s


CFD ∆T = 5.5 C




Velocity = 5.2 m/s

CFD ∆T = 76.5 C Test Coolant ∆T = 4.7 C Test Charged Air ∆T =63.7 C


Min

Max

Min

Max

Min

Max

Min

Max



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


Results: Existing Vehicle – Max Torque Condition Radiator








Min

Max

Min

Max

Min

Max

Min

Max


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


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


New Vehicle – Geometry Details

Intercooler – Radiator -Fan Module (IRFM)


Hot air recirculation in front of intercooler


Path Lines coloured by Temperature ( C)

Results: New Vehicle – Under-hood Thermal Flow Field





Results: New Vehicle – Under-hood Thermal Flow Field


Results: New Vehicle – Baseline IRFM Packaging

Intercooler – Radiator –Fan Module


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.




Results: New Vehicle – Under-hood Thermal Flow Field Baseline – IRFM Packaging Improved – IRFM Packaging

No hot air recirculation in front of intercooler




Velocity = 5.2 m/s

CFD ∆T = 78.5 C

Intercooler




Velocity = 5.2 m/s

CFD ∆T = 70.1 C


Results: New Vehicle – Max Power Condition

Min

Max

Min

Max

Min

Max

Min

Max


Intercooler


Improved ambient air temperature profile at the intercooler inlet face

Baseline – IRFM Packaging Improved – IRFM Packaging




Velocity = 5.2 m/s

CFD ∆T = 78.5 C

Intercooler




Velocity = 5.2 m/s

CFD ∆T = 70.1 C



Min

Max

Min

Max

Min

Max

Min

Max


Intercooler


Improved ambient air temperature profile at the intercooler inlet face





Radiator





Min

Max

Min

Max

Min

Max

Min

Max


Radiator


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


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


THANK YOU !!

Contact:

Ashok Patidar

[email protected]

validation and optimization of front end cooling module for commercial vehicle … ·...

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