Bech, Alexander (2018) Thermal Analysis and ... - Nottingham ePrints

Bech, Alexander (2018) Thermal Analysis and Fuel Economy Benefits of Cylinder Deactivation on a 1.0l Spark Ignition Engine. PhD thesis, University of Nottingham.

Access from the University of Nottingham repository:

Copyright and reuse:

The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions.

This article is made available under the University of Nottingham End User licence and may be reused according to the conditions of the licence. For more details see:

For more information, please contact eprints@nottingham.ac.uk

Thermal Analysis and Fuel Economy Benefits of Cylinder Deactivation on a 1.0l Spark Ignition Engine

Thermal Analysis and Fuel Economy Benefits of Cylinder Deactivation on a 1.0l Spark Ignition Engine

Alexander Bech (BEng)

Thesis submitted to the University of Nottingham for the degree of Doctor of Philosophy October, 2017

Contents

Nomenclature ..................................................................................................................................I Subscripts .....................................................................................................................................IV Symbols .......................................................................................................................................... V Abbreviations ...............................................................................................................................VI Dimensionless Groups ............................................................................................................... VII Abstract...................................................................................................................................... VIII

Chapter 1 Introduction.................................................................................................................... 1 1.1 Overview.......................................................................................................................... 1 1.2 Mandate on CO2 Emissions Resulting from the Transport Sector in the EU ................... 2 1.2.1 An Introduction to Light Duty Automotive Applications of Cylinder Deactivation ... 3 1.3 Other Routes in Achieving the 98 g CO2/km EU Target by 2020 ................................... 5 1.4 CAE Tools ? Application for Proto-type Design and Development................................ 6 1.5 Aim and Objectives.......................................................................................................... 7 1.6 Layout of Thesis .............................................................................................................. 9 1.7 Contribution to Knowledge.............................................................................................. 9

Chapter 2 Literature Review ........................................................................................................ 11 2.1 Introduction.................................................................................................................... 11 2.2 Thermal Management .................................................................................................... 11 2.2.1 The Role of Cooling Circuits in Reducing Fuel Consumption .............................. 11 2.2.2 The Integrated Exhaust Manifold (IEM) and Downsizing .................................... 12 2.2.3 Inter-Bore Cooling Slit Effects on Local Temperatures, Spark Ignition Advance and Knock .............................................................................................................................. 13 2.3 Cylinder Deactivation .................................................................................................... 14 2.3.1 Methods for Deactivating Cylinders ...................................................................... 14 2.3.2 Valvetrain Mechanisms for Cylinder Deactivation................................................ 15 2.3.3 Transition from All Firing Cylinders to Deactivated Cylinders ............................ 21 2.3.4 In-cylinder Charge Behaviour When Shutting-Off Valves.................................... 21 2.3.5 Improving Catalyst Light Off Times ..................................................................... 23 2.3.6 Cylinder Deactivation Effects on Emissions.......................................................... 24 2.3.7 Varying Valve Lift ................................................................................................. 24 2.3.8 Oil Entrapment in Deactivated Cylinders .............................................................. 25 2.3.9 Minimising NVH when Deactivating a Cylinder................................................... 25 2.3.10 Other Techniques for Cylinder Deactivation ......................................................... 27 2.3.11 Dynamic Skip Fire ................................................................................................. 27 2.3.12 Future Advances: Koenigsegg Air Compressed and Free Valve Technology ....... 28 2.4 Cylinder Bore Distortion and Piston Ring Behaviour.................................................... 30 2.4.1 Piston Ring Conformity, Collapse and Flutter ....................................................... 31 2.4.2 Methods for Minimising Temperature Differences and Cylinder Bore Distortion 31 2.5 Concluding Remarks...................................................................................................... 32

Chapter 3 PROMETS Theory ...................................................................................................... 34 3.1 Introduction.................................................................................................................... 34 3.2 PROMETS: Basics and Model Elements....................................................................... 34 3.2.1 Model Inputs .......................................................................................................... 35 3.2.2 Lumped Capacity Analysis .................................................................................... 38

3.2.3 Accuracy and Stability ........................................................................................... 38 3.3 Friction Model ............................................................................................................... 40

3.3.1 Original Friction Model Description...................................................................... 40 3.4 Original Gas-side Heat Transfer Correlations................................................................ 42 3.5 Exhaust Gas Temperature Prediction............................................................................. 44 3.6 Coolant Side Heat Transfer............................................................................................ 44

3.6.1 Forced Convection and Nucleate Boiling .............................................................. 44 3.6.2 Coolant Circuit Set-Ups ............................................................................................. 45 3.7 Oil Circuit Model ........................................................................................................... 48 3.8 Fuel Consumption Prediction ........................................................................................ 51 3.9 Discussion ...................................................................................................................... 52

Chapter 4 Advancing PROMETS to Represent the 1.0litre Three Cylinder Engine.................... 54 4.1 Introduction.................................................................................................................... 54 4.2 Engine Details and Architecture .................................................................................... 54 4.3 Location of Thermocouples Used for Model Correlation.............................................. 54 4.3.1 Data Used for Model Correlation........................................................................... 59 4.4 Feature Revisions and Additions ................................................................................... 59 4.4.1 Integrated Exhaust Manifold (IEM)....................................................................... 59 4.4.2 Engine Component Masses .................................................................................... 60 4.5 Friction Model Revision for the TCE ............................................................................ 61 4.5.1 Original Friction Model Description...................................................................... 62 4.5.2 Engine Friction Validation..................................................................................... 63 4.6 Oil Circuit Model ........................................................................................................... 65 4.7 Revisions to the Gas-side Heat Transfer Expression ..................................................... 65 4.7.1 Methodology for Revision of Heat Transfer Model .............................................. 66 4.7.2 Comparison between the Original and Revised Model.......................................... 68 4.8 Revised Coolant Passage Heat Transfer ........................................................................ 74 4.8.1 Advanced Cooling Circuit Design Representation ................................................ 74 4.8.2 Modelling Quiescent Coolant in the Block............................................................ 76 4.9 Piston Cooling Jet Heat Transfer ................................................................................... 89 4.9.1 Piston Cooling Jet Discharge and Heat Transfer Coefficient ................................ 89 4.9.2 Piston Cooling Jet Model Validation ..................................................................... 91 4.10 Revised Fuelling and Intake Manifold Pressure Estimation .......................................... 93 4.10.1 Method for Estimating Turbocharged Intake Manifold Pressure........................... 93 4.10.2 Cylinder Volumetric Efficiency Estimation........................................................... 94 4.10.3 Iteration for Intake Manifold Pressure and Fuel Consumption Prediction ............ 97 4.11 Estimating the Work Done on the Gas in a Deactivated Cylinder............................... 101 4.11.1 Incentive for Estimating Motoring Work Penalty................................................ 101 4.11.2 Procedure for Measuring Reduction in Bottom Dead Centre Pressure................ 101 4.11.3 Work Done on the Gas in the Deactivated Cylinder............................................ 102 4.11.4 Estimated Mass Loss When Trapping an Exhaust Charge .................................. 104 4.11.5 Literary Suggestions for Reducing Prolonged Partial Vacuum and Oil Suction . 105 4.12 Discussion and Conclusions ........................................................................................ 105

Chapter 5 Modelled Changes in Heat Transfer due to Cylinder Deactivation ........................... 108 5.1 Introduction.................................................................................................................. 108 5.2 Heat Transfer Model Revision to Account for Cylinder Deactivation ........................ 108 5.2.1 Combustion Chamber Heat Transfer ................................................................... 108 5.2.2 Exhaust Side Heat Transfer.................................................................................. 109

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download