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Ignition Experiments by Nanosecond Repetitively Pulsed Discharges in Intense Turbulence for Super Lean Burn at Engine Condition

Institute of Fluid Science, Tohoku University-Kodai Uesugi, Youhi Morii, Taichi Mukoyama, Takuya Tezuka, Susumu Hasegawa, Hisashi Nakamura, Hidemasa Takana
Institute of Fluid Science, Tohoku University / ICE Lab. Far-Kaoru Maruta
  • Technical Paper
  • 2019-01-2160
Published 2019-12-19 by SAE International in United States
Ignition by Nanosecond Repetitively Pulsed Discharges (NRPD) at EXponential Increase of Minimum Ignition Energy (MIE-EXI) region under super lean SI engine conditions was studied. Fundamental experiments were conducted with a turbulent ignition test chamber with twin counter-rotating fans. The MIE-EXI region by arc discharge appeared over 6500 rpm of fan speed. In the MIE-EXI region (7000 rpm), successful ignition was achieved by establishing coupled ignition kernels with NRPD at 15 kHz although ignition was unsuccessful at 1 kHz. Results show that ignition by NRPD has potential advantages for lean burn applications. Preliminary engine test results with NRPD were also demonstrated.
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Novel Ignition Property Measurements for Various Fuels using a Micro Flow Reactor with a Controlled Temperature Profile

Institute of Fluid Science, Tohoku University-Hisashi Nakamura, Takuya Tezuka, Susumu Hasegawa
Tohoku University-Kaoru Maruta
Published 2015-09-01 by SAE International in United States
This paper presents new methodology of ignition property measurements using a micro flow reactor with a controlled temperature profile, which is a spin-off methodology developed through microcombustion studies during the last decade. Stable multi-stage reaction zones were observed in low flow velocity regime for hydrocarbons and it was found that unsteady multi-stage oxidations of hydrocarbons were examined by stable multi-stage reaction zones termed as weak flames. This methodology has been further applied to various fuels. Effects of research octane number of primary reference fuels on weak flames were examined and it was shown that stabilized temperature levels and appearances of weak flames have apparent correlations with RON. Recent works using the micro flow reactor were also introduced.
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Pressure and Octane Number Dependences of PRF/Air Weak Flames in a Micro Flow Reactor With a Controlled Temperature Profile

Tohoku Univ.-Mikito Hori, Akira Yamamoto, Takuya Tezuka, Susumu Hasegawa, Hisashi Nakamura, Kaoru Maruta
  • Technical Paper
  • 2011-08-0281
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
Ignition characteristics of PRF/air mixture were investigated using a micro flow reactor with a controlled temperature profile. In the low flow velocity region, stable weak flames were observed. Focusing on these weak flames, their responses to octane number and pressure were examined. Under the atmospheric pressure, low temperature oxidation was weakened and main reaction shifted to the higher temperature region as octane number increased. Under the elevated pressures, increasing low temperature oxidation and its shifts to lower temperature region were observed. These tendencies were intensified especially for the low octane-rated fuels.
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Three-Stage Reaction of n-Heptane/Air Mixture in Micro Flow Reactor With Controlled Temperature Profile

Tohoku Univ.-Akira Yamamoto, Hiroshi Oshibe, Hisashi Nakamura, Susumu Hasegawa, Takuya Tezuka, Kaoru Maruta
  • Technical Paper
  • 2009-08-0383
Published 2009-10-07 by Society of Automotive Engineers of Japan in Japan
Ignition and combustion characteristics of stoichiometric n-heptane/air mixture were investigated using micro flow reactor with controlled temperature profile. Various flame responses were experimentally obtained by changing mean flow velocity at the inlet of the tube. Especially in the low velocity condition, distinct two weak flames and broaden luminous zone were observed in the flow direction. Results of 1-D steady computation showed triple peaks of heat release rate at low velocity. These three flames are considered to be cool, blue and hot flames, respectively.
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Development of a New 4-Valve/Cylinder Small Di Diesel Engine-Development of High-Pressure Fuel Injection System (Report 3)

Nissan Motor Co., Ltd.-Kazuhiko Takahashi, Hiroaki Nakai, Tetuya Kamihara
Zexel Corp.-Hisashi Nakamura
  • Technical Paper
  • 988082
Published 1998-05-20 by Society of Automotive Engineers of Japan in Japan
Nissan's new 4-valve/cylinder small DI diesel engine can reduce emissions, fuel consumption and combustion noise by new combustion concept and new systems. This paper describes the new injection system, which has a new distributor-type, high-pressure fuel injection equipment and a new two-spring nozzle
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Development of New Distributor Type Fuel Injection System for High-Speed Small Di Diesel Engines

Zexel Corp.-Hajime Machida, Hisashi Nakamura, Jun Matsubara, Noriyuki Abe, Hiroshi Ishiwata
  • Technical Paper
  • 978127
Published 1997-05-21 by Society of Automotive Engineers of Japan in Japan
Distributor-type, high-pressure Fuel Injection Equipment (FIE) is one of the practical systems for high-speed small DI diesel engines.The injection performance of new distributor-type FIE is shown in comparison with the conventional-type FIE, so called VE, in-line and unit injector for this new FIE, it is possible to control the initial injection rate by the combination of cam profile modification and two-spring injector. Finally, high-flow coefficient nozzle is introduced.