PRESENTATION OUTLINE. Introducing D.I.E.M. Review of main projects: Basic Research Review of main projects: Design support

Transcription

1 CFD ACTIVITY AT DEPARTMENT DIEM

2 PRESENTATION OUTLINE Introducing D.I.E.M. Review of main projects: Basic Research Review of main projects: Design support

3 INTRODUCING D.I.E.M. Human Resources Hardware Facilities CFD Codes Research and Application Fields Contracts A Way to Work

4 INTRODUCING DIEM Human Resources FULL PROFESSOR: ASSOCIATED PROFESSOR: Piero Pelloni Gian Marco Bianchi ASSISTANT PROFESSORS: PERMANENT ENGINEERS: Stefania Falfari,PhD Giulio Cazzoli, PhD Federico Brusiani, PhD Claudio Forte, PhD Ph.D. STUDENTS: Sergio Negro (2008->) ENGINEER FELLOWS: Marco Costa Gherardo Gualandi - Gaspare Argento

5 INTRODUCING DIEM CFD Codes ENGINE SIMULATIONS: PREMIXED NON-PREMIXED COMBUSTION PFI-GDI SIMULATION KIVA3_UNIBO FIRE2010 LES SIMULATION FLUENT 12 GENERAL FLUID-DYNAMICS: DYNAMICS: FLUENT 12 HYDRAULIC SIMULATION OF FLUID-POWER/ INJECTION SYSTEMS: AUTOMATED OPTIMIZATION: AMESIM modefrontier

6 INTRODUCING DIEM Research and application Fields CFD ANALYSIS OF ICE INTAKE/EXHAUST SYSTEMS CFD ANALYSIS OF ICE COMBUSTION SYSTEMS CFD ANALYSIS OF VACUUM PUMP ANALYSIS OF INJECTION SYSTEMS ANALYSIS OF FLUID-POWER SYSTEMS

7 INTRODUCING Contracts INTERNAL COMBUSTION ENGINES FERRARI RACING/ SERIES LAMBORGHINI DUCATI RACING/MOTOR PIERBURG PUMP TECHNOLOGY PIAGGIO & C S.p.A MAGNETI MARELLI VM-MOTORI ANSYS GERMANY GmbH Former Partner: FIAT-GM Powertrain, De Longhi, Bucher Hydraulics, Paioli

8 INTRODUCING DI A way of work: To know and apply ADVANCED RESEARCH - New CFD methodologies or models development - Knowledge of model behaviour via implementation in our own codes - Test of models and numerics - Investigations of basics physics DESIGN SUPPORT OR TECHNOLOGY TRANSFER TO COMPANY CFD is available: it must be used since it offers a unique tool of investigation

9 Basic Research

10 Liquidid Jet tatomization ti 3D INVESTIGATION OF ATOMIZATION O BASIC PHYSICS ANALYSIS OF BASIC PROCESSES VIA QUASI-DIRECT SIMULATION IMPROVEMENT OF ATOMIZATION MODELS CFD Grid 1 mm Caso turbolento Turbulent Caso laminare Laminar Nucleo Core Strutture Detached liquide

11 Liquidid Jet tatomization ti DEVELOPMENT OF ATOMIZATION MODEL FOR LIQUID JET BASED ON SIMPLE 2D SIMULATIONS Injection velocity [m/s] Back density Mean fluctuation level Orifice diameter [kg/m 3] [% of vinj] [μm] CASES pdf DROPLET SIZE PDF 100 m/s m/s 400 m/s Droplets Diameter (μm) 2 1 pn( χ ) = ( χ ) e n 2 (2) Γ( n 2) 2 n χ ILASS 2004 ILASS 2004 HTCE 2004

12 3-Phase Nozzle Flow Simulation COUPLED NOZZLE FLOW LIQUID JET ATOMIZATION Internal Flow Simulation Generations of Nozzle Files Spray Simulation FROM NOZZLES TO SPRAYS

13 LES DEVELOPMENT OF ROBUST LES FOR NON REACTIVE FLOW IN FIXED GRIDS ICE STEADY (NON-REACTIVE) FLOW Thobois, Rymer, Souleres, Poinsot, SAE Paper, mm m 20mm m D1 [mm] 120 D2 [mm] 16 D3 [mm] 34 L1 [mm] 300 L2 [mm] 132 Valve lift [mm] 10 LDA velocity profiles are available on two planes at 20mm and 70mm from cylinder head. Numerical Settings: same as previous using Fluent 6.2

14 LES 1,2 1 0,8 LES_LDKEM LES_WALE LDA 0,6 20mm U(t)/Uo 0,4 0,2 0 70mm -0,2-0,4 On the 20mm plane, both LES models allow to obtain a reasonable good agreement between numerical and experimental profiles. U(t)/Uo -0,6-1 -0,5 0 0,5 1 1,2 r/r 1 0,8 0,6 0,4 0,2 LES_LDKEM LES_WALE LDA On the 70mm plane, both LES models fit the overall experimental trend except for the flow under the valve. 0-0,2-0,4-0,6-1 -0,5 0 0,5 1 r/r 14/72

15 S.I. LAGRANGIAN IGNITION MODEL λ=1 λ=1.3 λ=1.55 TCI [60 mj] CDI [6 mj] EFFECT OF AIR INDEX VARIATION CAPTURED FLAME HOLDER EFFECT MODELLED

16 WALL FILM MODEL IMPLEMENTED IN FIRE 2010 Beta Release

17 FUEL FLASHING P NO FLASH Po a b critical point FLASH liquid Ps(To) spinodal limit P1 Psat a1 b2 b1 metastable region vapour Nucleation Model Is function of the superheating degree T1 The nozzle flow T2 T Homogenous Relaxation Model (HRM). A relaxation time is required to model the transition from non equilibrium to equilibrium Nozzle-Spray Coupling Atomization Model Relates the bubble diameter to the void fraction and the superheated degree at nozzle exit Spray Evaporation

18 OOP Code DEVELOPMENT OF A NEW PARALLEL OBJECT ORIENTED CODE FOR COMPUTATIONAL CONTINUUM MECHANICS (CCM) IN FORTRAN 95. NEMO - Numerical Engine for Multiphysics Operators Contributors: - University of Bologna Main Driver (with fundamental contribution by Dr. Stefano Toninel) - University of Rome Tor Vergata (Prof. Bella & Dr. Filippone): parallel solvers. - University of Massachusetts at Amherst (Prof. Schmidt): node smoothing algorithm based on cell quality

19 Design Support

20 REVIEW OF MAIN PROJE ICE Non-Reactive Flow Simulation APPLICATION OF BOUNDARY LAYER SOLUTION IN RANS STEADY FLOW SIMULATION Two-layer Wall-functions NO Recirculation Recirculation Discharge coeff. W.F. T.B.L EXP Valve lift

21 Non-Reactive Flow Simulation MULTI-CYCLE INTAKE SIMULATION

22 SI Engines Combustion System Optimization OPTIMIZATION OF RACING ENGINE COMBUSTION EFFICIENCY: CFD IN DESIGN STEPS F1 TEAM AND DUCATI MotoGp (2003->) bar bar bar bar bar IMEP bar +0.59% PMI -2.78%ANT. p583 p583cmd052a p681 p681cmdstudio2 p681cdm053estep4 Studio bar Studio2 Studio2cmdp bar Studio2cmdp681 p747cdm053estep bar p747cdm053estep4.2 p747cdmp bar bar bar [BTDC] [BTDC] [BTDC] [BTDC] [BTDC] [BTDC] [BTDC] [BTDC] START CONFIGURATION [BTDC] [BTDC] [BTDC] Anticipo Ottimale SPARK ADVANCE

23 HSDI Diesel Engine Modeling IN COOPERATION WITH VM-Motori Motori (1996->) AND FIAT-GM ( ) 2004) DEVELOPMENT OF NON-EQUILIBRIUM TURBULENCE CORRECTION ADVANCED COUPLING BETWEEN INJECTOR FLOW AND ATOMIZATION MODEL DEVELOPMENT OF SUITABLE ATOMIZATION MODELS APPLICATION TO HSDI DIESEL ENGINE DEVELOPMENT LOW COMBUSTION TEMPERATURE CONCEPT LOW COMBUSTION TEMPERATURE CONCEPT DEVELOPMENT BASED ON HIGHLY COOLED EGR RATE

24 Port-Fuel Optimization in SI Engines Racing Application MIXTURE FORMATION ANALYSIS WALL-FILM ANALYSIS EFFECT OF LUBRICANT CONTAMINATION WITH FUEL

25 Port-Fuel Optimization in SI Engines CFD PROVIDED A ZERO COST SOLUTION TO REDUCE LUBRICANT CONTAMINATION WITH FUEL Percen ntage of total ma ass injected [%] 0,1 2 Advanced injection Retarded injection Standard injection 0,075 1,5 0,05 0, Angle [ ] 1 0,5 Percen tage of total mas ss injected (stand dard case) [%]

26 Injection System Development A PROJECT IN COOPERATION WITH MAGNETI MARELLI ( ) 2005) DEVELOPMENT OF ELECTRO-MAGNETIC MODEL DEVELOPMENT OF ADVANCED DRIVING CIRCUIT 1D-3D SIMULATION OF INJECTOR AND SYSTEM DYNAMICS FOR DESIGN SIMULATION OF TWO-PHASE FLOW COUPLING BETWEEN INTERNAL NOZZLE FLOW AND ATOMIZATION MODEL

27 LES - F1 RACING CAR AIR BOX A PROJECT IN COOPERATION WITH FERRARI RACING (SAE PAPERS)

28 MULTI-PHASE OF LUBRICANT VANE PUMP A PROJECT IN COOPERATION WITH PIERBURG PUMP TECHNOLOGY Computational domain Exhaust phase Bubble implosion pressure ripple

29 UREA INJECTION AFTER TREATMENT

30 EXHAUST SYSTEMS FULLY SIMULATION OF EXHAUST SYSTEM TILL AFTERTREATMENT FULLY SIMULATION OF EXHAUST SYSTEM TILL AFTERTREATMENT DEVICE

31 SI COMBUSTION INDICATING COMBUSTION ANALYSIS - KNOCK - CYCLE TO CYCLE VARIATION 16 Distribuzione Cil1 PMI - MFB Distribuzione Cil6 PMI - MFB BMEP PMI 14.5 BMEP PMI LAMBDA 88 ADV71 LAMBDA 91 ADV74 LAMBDA 94 ADV75 LAMBDA 98 ADV MFB MFB50