1Preferred partner in engine performance simulation

Subir MandalIST

India GT-SUITE Conference 2018

Integrated Simulation Technologies Pvt Ltd

Preferred partner in engine performance simulation

UHC System Sizing to Eliminate Engine Overheating when Grill and Radiator Fronts are Partially Blocked by Mud & Dirt

2Preferred partner in engine performance simulation

Engine Cooling System

Maintain the working temperature of every engine components below the safety limitThermal balance between the heat extracted from the engine hardware and the heat released to external ambient through radiator

Engine performance/efficiencyEmissionsReliability of the componentsClearance of the engine’s static and moving parts CarburetionLubricant properties

Rated powerPeak torqueIdleHot airBlockageClimbing

2

1

4

3

Heat transfer areaCoolant flowAirflow

3Preferred partner in engine performance simulation

Problem Statement

25% of both front grill and radiator core are blocked by mud and dirt50OC ambient air temperature

Suggest design improvement to eliminate engine overheating when it operates under worst conditions

Engine overheating (T_Coolant_EngOut > 110OC)

Tractor engine

Less temperature gradient between coolant & ambient airLess heat rejection in radiator

Less airflow through radiatorLess heat rejection in radiator

4Preferred partner in engine performance simulation

Discretized UHS

Underhood system in

Quasi-3D environment

FanFan

shroud

Outlet

Engine cooling

system circuit

Heat addition

Pump

UHC

Grill Opening

Radiator front

blocked

Flow domain Engine

Radiator

Front grill

blocked

Quasi-3D UHS

Radiator

Fan

Virtual Cooling System Model

Underhood system in

Quasi-3D environment

5Preferred partner in engine performance simulation

ChallengesFan map data:

Insufficient number of data pointsExtremely raw data setMap was rationally scaled to match performance

Radiator performance map data:Insufficient number of data pointsData was rationally pre-processed to get a good fit of performance parameters

Coolant properties vs engine heat addition:Heat addition from engine to coolant was calculated analyticallyAdjustment to make heat addition, temperature rise, and coolant properties (ρ , Cp) compatible

Modeling blockage due to mud and dirt:Front grillFront of radiator

6Preferred partner in engine performance simulation

Model Calibration

8 operating points including rated power, peak torqueAmbient temperature = 42OCNo blockage of front grill and radiator frontPredicted radiator inlet and outlet temperature w.r.t. their measured values within ±1.2OC

7Preferred partner in engine performance simulation

Performance under Worst Conditions (1/2)

Engine overheating limit is crossed by 1OC – 6OC under 50OC hot ambient & no blockage conditionsEngine overheating limit is crossed by 17OC – 24OC under 50OC hot ambient & blockage conditions

8Preferred partner in engine performance simulation

Performance under Worst Conditions (2/2)

8 OC increase in ambient temperature leads to 8.5OC temperature rise for both engine out coolant and radiator out air25% blockage resulted in temperature rise of 17OC for engine out coolant; and 6OC for radiator out airThere is a reduction in airflow through radiator by 16.5% due to 25% blockage

9Preferred partner in engine performance simulation

Model Validation

Virtual cooling system model is robust enough to be used for further investigation

Simulation Measured Simulation Measured

dT_Coolant_EngOut for T_Amb change 42OC to 50

OC K 8.6 8 8.7 8.1

dT_Coolant_EngOut due to 25% blockage K 18.5 19.7 17.7 18.4

dAirFlowRate_Rad due to 25% blockage % -16.6 -15.8 -16.5 -16.2

Peak torqueParameters Unit

Rated power

25% of front grill blocked 25% of radiator front blocked

10Preferred partner in engine performance simulation

25 mm taller & 20 mm wider radiator core- Tube length = +25 mm- Number of tubes = +(2x5=10)

100% increase in coolant flow rate- Higher pump power consumption

A-1

A-2

A-3

Temperature reduction of 6OC – 8OC

Temperature reduction of 19OC – 26OC

Temperature reduction of 19OC – 27OC

Approach to Eliminate Engine Overheating

65-80% increase in airflow rate- Fan drive ratio from 1.7 to 3.2 OR

through larger diameter fan- Higher fan power consumption- More space required

100 mm taller & 100 mm widerradiator core- Tube length = +100 mm- Number of tubes = +(10x5=50)

100% increase in coolant flow rate- Higher pump power consumption

25% increase in airflow rate- Fan drive ratio from 1.7 to 2.6

OR through larger diameter fan- Higher fan power consumption- More space required

25 mm taller & 20 mm wider radiator core- Tube length = +25 mm- Number of tubes = +(2x5=10)

100% increase in coolant flow rate- Higher pump power consumption

11Preferred partner in engine performance simulation

Air velocity at radiator inlet

Coolant side temperature

No blockage @ 50OC 25% blockage @ 50OC 25% blockage @ 50OC @ Optimized

No blockage @ 50OC 25% blockage @ 50OC 25% blockage @ 50OC @ Optimized

Contours Plots of Radiator

12Preferred partner in engine performance simulation

Recommended UHC system arrangement to eliminate engine overheating

25 mm taller & 20 mm wider radiator core- Tube length = +25 mm- Number of tubes = +(2x5=10)

100% increase in coolant flow rate- Higher pump power consumption

65-80% increase in airflow rate- Fan drive ratio to be increased from 1.7 to 3.2 OR through larger diameter fan- Higher fan power consumption- More space required

The new radiator has heat rejection capacity 12 kW higher than the existing one

Conclusion