1 / 13

Auto-Ignited Kernels during Knocking Combustion in a Spark-Ignition Engine

Auto-Ignited Kernels during Knocking Combustion in a Spark-Ignition Engine. Okayama University Nobuyuki KAWAHARA Eiji TOMITA. Knocking cycle. Standard cycle. End-gas. Okayama University. Requirements of spark-ignition (SI) engine

niles
Télécharger la présentation

Auto-Ignited Kernels during Knocking Combustion in a Spark-Ignition Engine

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Auto-Ignited Kernels during Knocking Combustion in a Spark-Ignition Engine Okayama UniversityNobuyuki KAWAHARA Eiji TOMITA

  2. Knocking cycle Standard cycle End-gas Okayama University Requirements of spark-ignition (SI) engine - Lower fuel consumption - Reduced emission of pollutants. Higher thermal efficiencies Engine knocking due to higher compression ratio Background

  3. Okayama University Valve-stopper Solenoid Valve Valve-closure signal Thermocouple Pressure transducer Spark electrode Water Out In Elongated piston Bore: 78 mm Stroke: 85 mm Compression ratio: 9.02 Engine speed: 600 rpm Mixture tank Heater Crank angle pulse Flywheel TDC signal Rotary encoder Electric motor Compression-expansion engine

  4. Side view Unburned gas Burned gas Ignition Valve closing 180 210 240 270 300 330 360 (TDC) (BDC) Crank angle, deg. Okayama University Bore: 78 mm Stroke: 85 mm Compression ratio: 9.0 Engine speed: 600 rpm Top view Out Water In Timing chart Compression-expansion engine

  5. Experimental condition KInt 0 10 5 15 Time from ignition, ms Okayama University n-C4H10 (94) 1.0 40, 50, 60kPa 335～355deg. H2 1.0 40kPa 335～360deg. Fuel (Octane number) Equivalence ratio, φ Initial pressure, P0 Spark ignition timing, θIT Use of Ar&O2 mixture instead of air Knock intensity: KInt H.P.F 2.5kHz Experimental condition

  6. Mirror Measurement point Cylinder Experimental methods Valve High-speed video camera Cassegrain optics Shimadzu Hyper vision, HPV-1 Nac Image Technology, MEMRECAM GX1 Spark electrode Pressure Transducer PC Electric motor Flywheel

  7. P0=50kPaΘIT=350deg. P0=60kPaΘIT=340deg. P0=60kPaΘIT=345deg. KInt=0.180MPa KInt=0.434MPa Standard cycle Okayama University n-Butane(Φ=1.0) Rec.Speed:32kf.p.s Rec.Expose:1/8 Knock image (n-Butane)

  8. a b c d e f g Normal cycle 4 4 3 3 2 2 Pressure, MPa P0=50kPa qIT=350deg. P0=60kPa qIT=345deg. 1 1 0 0 350 360 370 380 350 360 370 380 Auto-ignited kernel Crank angle, deg. Flame front Knocking cycle A B C D E F G

  9. KInt=0.491MPa 360.0deg.～366.4deg. Rec.speed:63kfps Auto-ignited kernel Flame front B D Okayama University A B C D E F G H I B Φ=1.0 P0=60kPa, ΘIT=345deg. C A E G H F I Knock image and pressure history (n-Butane)

  10. KInt=0.491MPa 360.0deg.～366.4deg. Rec.speed:64kfps Okayama University A B C D E F G H I B Φ=1.0 P0=60kPa, ΘIT=345deg. C A D E G H F I Knock image and pressure history (n-Butane)

  11. Okayama University f = 1.0 , P0=60kPa , T0=323K , Rec.speed : 20kfps. C4H10 , ΘIT=345deg. C4H10 , ΘIT=360deg. CH4 , ΘIT=340deg. Kint=0.07MPa Non-knock condition Non-knock condition 4 3 Pressure , MPa 2 1 0 320 340 360 380 400 420 320 340 360 380 400 420 320 340 360 380 400 420 Crank angle , deg. Crank angle , deg. Crank angle , deg. Knock image and pressure history (n-Butane)

  12. Okayama University Normal cycle Knocking cycle H2-Air φ=1.0 P0=60kPa T0=323K θi=360deg. H2-O2-Ar φ=1.0 P0=40kPa T0=323K θi=360deg. Compared normal cycle with knocking cycle Rec. speed=60,000fps Rec. speed=60,000fps 3 3 Kint=0.03MPa Kint=1.53MPa 2 2 Pressure, MPa 1 1 0 0 360 365 370 375 380 360 365 370 375 380 Crank angle, deg. Crank angle, deg.

  13. A2 B1 A1 B2 Okayama University Pressure wave Knocking cycle Auto-ignition H2-O2-Ar φ=1.0 θi=340deg. Rec. speed=250,000fps Exposure time=2ms Kint=0.99MPa Frequency=7.35kHz 136ms Visualization of pressure wave and estimation of the frequency

More Related