1 Introduction (10 min) Experimental Activities (60 min) 3.1 Injector geometry assessment Yongjin Jung* (KAIST/Sandi), Peter Hutchins (Infineum/ESRF) 3.2 Rate-of-injection Raul Payri* (CMT), Scott Parrish (GM) 3.3 Spray Visualization (liquid/vapor penetration & angle) Julien Manin* (SNL), Gilles Bruneaux (IFPEN), Scott Parrish (GM), Luigi Allocca (IM), Josh Lacey (Melbourne) 3.4 Drop size measurement (Phase Doppler Interferometry) Scott Parrish* (GM) Modeling Activities (40 min) 3.5 Internal flow modeling using ideal geometry Ron Grover* (GM) 3.6 Spray modeling Noah Van Dam* (UW), Tommaso Lucchini (Politecnico di Milano), Sibendu Som (ANL) Future activities (10 min) *Discussion Leader ECN3 – Spray G Preliminary Program
2 Gasoline Spray (Spray G) Topic 3.2Rate-of-injection Topic 3.2 Rate-of-injection Raul Payri* (CMT) Scott Parrish (GM) Spray G – Rate of Injection
3 Spray G – Injection Rate Control of command signals with Delphi driver + pulse generator. Injector body temperature control. CMT SetupGM Setup Fuel is accumulated in a big volume System for injector temperature control
4 Spray G – Injection Rate (CMT) Methodology Experimental instruments – A commercial EVI-IAV system (Bosch method) is used. – Pressure regulated in the rail. – Additional pressure is measured in the rail with a Kistler sensor – Control of command signals of the injector with driver + pulse generator. Outputs – Injection rate shape. – Total amount of fuel injected.
5 Spray G – Injection Rate (CMT) Mass measured with a gravimetric scale Time [s] ΔP EVI [bar] Injection rate [g/s] Mass-flow meter output signal 50 injections A t : EVI mass flow meter a : speed of sound f(p,T) Time [s] Injection rate [g/s] comparison with Averaged injected mass - EVI
6 Spray G – Injection Rate Shot to shot dispersion on GM injector 28 Similar results obtained for all injectors in GM or CMT ≈ 310 µs≈ 780 µs Injector 28, Spray G Conditions – Iso- Octane, 20 MPa, 90C, 680 µs, 6 bar column pressure. Rate Meter: IAV (rate tube method)
7 Spray G – Injection Rate (CMT) Nominal point comparison
8 Rail pressure Influence for injector #26 Spray G – Injection Rate (CMT)
9 Back pressure Influence for injector #26 Spray G – Injection Rate (CMT) Small variations in BP affect injection dynamics but barely change the total injected mass. A high BP “smoothes” the opening and closing of the injector.
10 Spray G – Injection Rate (CMT) Frequency Influence on injection rate At 1Hz (red signal) the injector closes sooner for any ET.
11 Spray G – Injection Rate (CMT) Frequency Influence CMT vs GM Injector 16 GMInjector 26 CMT
12 CMT Measurement comparison – Energizing time Spray G – Injection Rate (CMT) Mass flow curves at different ET overlap Robust operation
13 Use of Delphi ECU to assure equal electrical signals in all research participant groups Injector temperature control is important Spray “G” injectors perform very well in terms of shot to shot dispersion (all units) Similar injected quantities for the different injectors, it will be possible to adjust slightly the ET to inject 10 mg in all the cases if it is necessary Known influence of injection pressure or Energizing Time Back pressure affects the dynamics of the injector (specially at 20 bar) Small effect of injection frequency on injection rate Probably this effect is due to thermal issues in the injector Very difficult to properly measure 1Hz injection frequency with a gravimetric balance due to the small injected quantity Spray G – Injection Rate (Conclusions)
14 CMT will construct a test rig to measure spray momentum for Spray “G” injector Compare injection rate derived from spray momentum and measured with injection rate Periodic check of injection rate after extensive campaigns are performed in high pressure and high temperature vessels Understand differences in injected quantities between different injector samples (when differences are the order of more than 5%) Determination of a different energizing time for each injector so that exactly 10 mg/st could be injected Possible generation of a virtual injector “clean signal” so that modelers could use it Spray G – Injection Rate (Future work)