NEDC Simulation with GT-Drive Dipl.-Ing. R. Kuberczyk Prof. Dr.-Ing. M. Bargende 12 Geschwindigkeit [km/h] 1 8 6 2 2 6 8 1 12 Zeit [s] Slide 1
Overview 1. Introduction 2. Simulation Background 3. Investigated Vehicles. Split of loss calculation in the NEDC 5. Conclusion Slide 2
Introduction NEDC and Split of Loss Calculation: Split of loss calculation in combustion engines is commonly used for comparing combustion systems on the test bench Gives an idea how to optimize the internal combustion to increase efficiency How to do a split of loss calculation based on the NEDC? Slide 3
Overview 1. Introduction 2. Simulation Background 3. Investigated Vehicles. Split of loss calculation in the NEDC 5. Conclusion Slide
Simulation background 12 City Cycle today EUDC Geschwindigkeit Vehicle speed [km/h] 1 8 6 2 Slide 5 2 6 8 1 12 time Zeit [sec] [s]
Simulation background GT-DRIVE MODEL Vehicle GT-POWER MODEL SI-Engine MEASURED DATA/ Engine Operating Map Diesel-Engine coupled calculation COMBUSTION PROCESS ANALYSIS/ Split of Losses NEDC Slide 6
Overview 1. Introduction 2. Simulation Background 3. Investigated Vehicles. Split of loss calculation in the NEDC 5. Conclusion Slide 7
Investigated Vehicles Vehicle weight: 15 kg gearbox: 6-gears (mechanical gearbox) cw-value:,27 SI-Engine number of cylinders: engine displacement: 2198 cm³ power: 11 kw (56 rpm) compression ratio: 11,3 Diesel-Engine number of cylinders: engine displacement: 218 cm³ power: 17 kw (2 rpm) compression ratio: 16,5 Slide 8
Overview 1. Introduction 2. Simulation Background 3. Investigated Vehicles. Split of loss calculation in the NEDC 5. Conclusion Slide 9
Split of loss calculatin in the NEDC -loss by real charge -loss by not optimal position of the combustion centre -loss by HC+CO-emissions -loss by finite combustion duration -loss by real caloric -loss by heat release through cylinder walls -expansion loss -compression loss -loss by ideal gas exchange today -loss by real gas exchange -loss by total gas exchange -mechanical loss Intension: Where does a vehicle with a SI-engine compared to the vehicle with a diesel engine loose efficiency? Slide 1
Slide 11 V [km/h] Loss by not optimal position of the combustion center [%] 1 8 6 gear Gang [-] 12 2 5 3 2 1 Drehzahl rpm [1/min] [1/min] bmep pme [bar] [bar] L. V. by nicht not opt. CC SWP [%] [%] 8 6 2 35 25 15 5 1 8 6 2 Idle part=18% SI-Engine Diesel Engine 775 825 875 925 975 125 175 1125 1175 time Zeit [sec] [sec]
Slide 12 V [km/h] Loss by total gas exchange [%] 1 8 6 gear Gang [-] 12 2 5 3 2 1 Drehzahl rpm [1/min] [1/min] bmep pme [bar] [bar] L. by total V. ges. g.exch. LW [%] 8 6 2 35 25 15 5 2 16 12 8 SI-Engine Diesel Engine 775 825 875 925 975 125 175 1125 1175 time Zeit [sec] [sec]
Slide 13 V [km/h] Mechanical loss [%] 1 8 6 gear Gang [-] 12 2 5 3 2 1 Drehzahl rpm [1/min] [1/min] bmep pme [bar] [bar] 35 25 15 mechanische mechanical L. V. [%] 8 6 2 5 2 16 12 8 LL=27% SI-Engine Diesel Engine Losses will be summed up 775 825 875 925 975 125 175 1125 1175 time Zeit [sec] [sec]
Slide 1 Energy Losses summed up in the EUDC [%] (without engine idle part) Which losses are higer with SI-Operation? SI-engine Diesel engine +,2% + % higher because of unsteady effects + 1,5% L. real charge L. n. opt. PCG L. HC+CO emis. L. fin. comb.dur. L. real caloric L. wall heat Exp. Loss Comp. Loss L. ideal GE L. real GE L. total GE mech. Loss e.g. Stratified Operation allows reduction of the gas exchange losses! Energy Loss [%]
Slide 15 V [km/h] 1 8 6 Gang gear [-] 12 Stratified Operation in EUDC Loss by total gas exchange [%] 2 5 3 2 1 Drehzahl rpm [1/min] [1/min] bmep pme [bar] [bar] L. of total V. ges. gas. LW ex. [%] [%] 8 6 2 35 25 15 5 2 16 12 8 Stratified Operation SI-Engine Otto Diesel Diesel Engine 775 825 875 925 975 125 175 1125 1175 time Zeit [sec] [sec]
Overview 1. Introduction 2. Simulation Background 3. Investigated Vehicles. Split of loss calculation in the NEDC 5. Conclusion Slide 16
Conclusion Split of loss calculation with GT-Drive: Split of loss calculation is very fast and useful for analysing combustion systems Useable on the test bench or based on data coming up with the GT-Power Simulation Split of loss calculation coupled with GT-Drive allows a deep understanding of the different behavior of cars with SI-engines and Diesel engines Powerful Tool to understand where to reduce the fuel consumption in the NEDC Slide 17
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