ソク ラトナック (ソク ラトナック)

写真a

所属

研究院(研究機関) 次世代自動車研究機構

職名

主任研究員(研究院准教授)

メールアドレス

メールアドレス

ホームページ

http://www.f.waseda.jp/jin.kusaka/

学歴 【 表示 / 非表示

  • 2012年
    -
    2015年

    早稲田大学   Mechanical Engineering   工学博士(指導教員:草鹿 仁 , 大聖 泰弘)  

    Supervisors: Jin Kusaka, Yasuhiro Daisho

  • 2009年
    -
    2011年

    Institut Teknologi Bandung   MSME (with Distinction)  

    Supervisors: Iman K Reksowardojo, Wiranto Arimunandar, Tirto Prakoso, Toshio Shudo

  • 2006年
    -
    2009年

    Institut de Technologie du Cambodge   Génie Mécanique   Diplôme d'Ingénieur (1st class honor degree)  

  • 2003年
    -
    2006年

    Institut de Technologie du Cambodge   Génie Mécanique   Diplôme Universitaire de Technologie (1st class honor degree)  

学位 【 表示 / 非表示

  • 2015年   Waseda University   Dr. Eng.

  • 2011年   Institut Teknologi Bandung   MSME (cum laude)

  • 2009年   Institute de Technologie du Cambodge   Diplôme d'Ingénieur (1st class honor)

  • 2006年   Institut de Technologie du Cambodge   Diplôme Universitaire de Technologie (1st class honor)

経歴 【 表示 / 非表示

  • 2020年
    -
    継続中

    早稲田大学   研究院准教授 (w/ 草鹿 仁 教授)

  • 2018年
    -
    2020年

    早稲田大学   研究院講師 (w/ 草鹿 仁 教授)

  • 2016年
    -
    2017年

    スズキ自動車会社   エンジニア   Engineer

  • 2015年
    -
    2016年

    早稲田大学   RA   Postdoctorate, Jin Kusaka Group

  • 2012年
    -
    2015年

    早稲田大学   TA   Research/Teaching Assistant, Jin Kusaka Group

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所属学協会 【 表示 / 非表示

  • 2021年
    -
    継続中

    IEEE Intelligent Transportation Systems Society

  • 2021年
    -
    継続中

    IEEE Vehicular Technology Society

  • 2021年
    -
    継続中

    Institute of Electrical and Electronics Engineers (IEEE)

  • 2018年
    -
    継続中

    自動車技術会

  • 2014年
    -
    継続中

    The American Society of Mechanical Engineers

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研究分野 【 表示 / 非表示

  • 熱工学   Electrified Vehicles ; Internal Combustion Engines

研究キーワード 【 表示 / 非表示

  • Computational Fluid Dynamics

  • Internal combustion engine

  • Transportation electrification

論文 【 表示 / 非表示

  • Experimental Investigation of Direct Fuel Injection into Low-Oxygen Recompression Interval in a Homogenous Charge Compression Ignition Engine

    Ratnak Sok, Jin Kusaka

    Journal of Energy Resources Technology     1 - 25  2021年09月  [査読有り]

    担当区分:筆頭著者, 責任著者

     概要を見る

    <title>Abstract</title>
    This work analyzed measured data from a single-cylinder engine operated under gasoline direction injection homogenous charge compression ignition (GDI-HCCI) mode. The experiments were conducted at a 0.95 equivalence ratio (φ) under 0.5 MPa indicated mean effective pressure and 1500RPM. A side-mounted injector delivered primary reference fuel (octane number 90) into the combustion chamber during negative valve overlap (NVO). Advanced combustion phase CA50 were observed as a function of the start of injection (SOI) timings. Under φ=0.95, peak NVO in-cylinder pressures were lower than motoring for single and split injections, emphasizing that NVO reactions were endothermic. Zero-dimensional kinetics calculations showed classical reformate species (C3H6, C2H4, CH4) from the NVO rich mixture increased almost linearly due to SOI timings, while H2 and CO were typically low. These kinetically reformed species shortened predicted ignition delays. This work also analyzed the effects of intake pressure and single versus double pulses injections on CA50, burn duration, peak cylinder pressure, combustion noise, thermal efficiency, and emissions. Advanced SOI (single-injection) generated excessive combustion noise metrics over constraint limits, but the double-pulse injection could significantly reduce the metrics (Ringing Intensity ≤ 5 MW/m2, Maximum Pressure Rise Rate = 0.6 MPa/CA) and NOx emission. The engine's net indicated thermal efficiency reached 41% under GDI-HCCI mode against 36% under SI mode for the same operating conditions. Under GDI-HCCI mode and without spark-ignition, late fuel injection in the intake stroke could reduce NOx to a single digit.

    DOI

  • Avoidance Algorithm Development to Control Unrealistic Operating Conditions of Diesel Engine Systems under Transient Conditions

    Rio Asakawa, Iku Tanabe, Kyohei Yamaguchi, Ratnak Sok, Jin Kusaka, Masatoshi Ogawa, Takuma Degawa, Shigeaki Kurita, Arravind Jeyamoorthy, Zhou Beini

    SAE Technical Paper Series    2021年09月  [査読有り]

    担当区分:責任著者

    DOI

  • Reaction Analysis and Modeling of Fast SCR in a Cu-Chabazite SCR Catalyst Considering Generation and Decomposition of Ammonium Nitrate

    Keiichiro Seki, Rikuto Ueyama, Yoshihisa Tsukamoto, Kenya Ogawa, Kohei Oka, Ratnak Sok, Jin Kusaka

    SAE Technical Paper Series    2021年09月  [査読有り]

    担当区分:責任著者

    DOI

  • Numerical Study on the Adaptation of Diesel Wave Breakup Model for Large-Eddy Simulation of Non-Reactive Gasoline Spray

    Ratnak Sok, Beini Zhou, Jin Kusaka

    ASME Technical Paper    2021年07月  [査読有り]

    担当区分:筆頭著者, 責任著者

     概要を見る

    <title>Abstract</title>
    Gasoline direct injection (GDI) is a promising solution to increase engine thermal efficiency and reduce exhaust gas emissions. The GDI operation requires an understanding of fuel penetration and droplet size, which can be investigated numerically. In the numerical simulation, primary and secondary breakup phenomena are studied by the Kelvin-Helmholtz/Rayleigh-Taylor (KH-RT) wave breakup models. The models were initially developed for diesel fuel injection, and in the present work, the models are extended to the GDI application combined using large-eddy simulation (LES). The simulation is conducted using the KIVA4 code.


    Measured data of experimental spray penetration and Mie-scattering image comparisons are carried out under non-reactive conditions at an ambient temperature of 613K and a density of 4.84 kg/m3. The spray penetration and structures using LES are compared with traditional Reynolds-Averaged Navier-Stokes (RANS). Grid size effects in the simulation using LES and RANS models are also investigated to find a reasonable cell size for future reactive gasoline spray/combustion studies. The fuel spray penetration and droplet size are dependent on specific parameters. Parametric studies on the effects of adjustable constants of the KH-RT models, such as time constants, size constants, and breakup length constant, are discussed. Liquid penetrations from the RANS turbulence model are similar to that of the LES turbulence model’s prediction. However, the RANS model is not able to capture the spray structure well.

    DOI

  • Experimental and Numerical Analysis on the Influences of Direct Fuel Injection Into Oxygen-Depleted Environment of a Homogeneous Charge Compression Ignition Engine

    Ratnak Sok, Kei Yoshimura, Kenjiro Nakama, Jin Kusaka

    Journal of Energy Resources Technology-ASME Transaction   143 ( 12 )  2021年03月  [査読有り]

    担当区分:筆頭著者, 責任著者

     概要を見る

    <title>Abstract</title>
    The oxygen-depleted environment in the recompression stroke can convert gasoline fuel into light hydrocarbons due to thermal cracking, partial oxidation, and water-gas shift reactions. These reformate species can influence the combustion characteristics of gasoline direct injection homogeneous charge compression ignition (GDI-HCCI) engines. In this work, the combustion phenomena are investigated using a single-cylinder research engine under a medium load. The main combustion phases are experimentally advanced by direct fuel injection into the negative valve overlap (NVO) compared with that of intake stroke under single/double-pulse injections. NVO peak in-cylinder pressures are lower than that of motoring due to the limited O2 concentration, emphasizing that endothermic reactions occur during the overlap. This phenomenon limits the oxidation reactions, and the thermal effect is not pronounced. The zero-dimensional chemical kinetics results present the same increasing tendencies of classical reformed species of rich mixture such as C3H6, C2H4, CH4, CO, and H2 as functions of injection timings. Predicted ignition delays are shortened due to the additions of these reformed species. The influences of the reformates on the main combustion are confirmed by three-dimensional computational fluid dynamics (CFD) calculations, and the results show that OH radicals are advanced under NVO injections relative to intake stroke injections. Consequently, earlier heat release and cylinder pressure are noticeable. Parametric studies on the effects of injection pressure, double-pulse injection, and equivalence ratio on the combustion and emissions are also discussed experimentally.

    DOI

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受賞 【 表示 / 非表示

  • Waseda Asia Special Fellowship for PhD Student (Full for 2012-2015)

    2012年09月   Waseda University;  

  • JICA Fellowship for Guest Research Associate at Kyoto University

    2012年08月  

  • JICA Fellowship for Visiting Researcher at Hokkaido University

    2012年07月  

  • JICA (AUN/SEED-Net) Fellowship for Graduate Student (Full for 2009-2011)

    2009年09月  

  • 1st class honor degree for Diplôme d'Ingénieur

    2009年07月   Institut de Technologie du Cambodge;  

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共同研究・競争的資金等の研究課題 【 表示 / 非表示

  • Development of high-efficiency gas engine for power generation by controlling flow of decarbonized fuels

    研究期間:

    2021年
    -
    2022年
     

    Beini Zou, Kyohei Yamaguchi, Ratnak Sok

    担当区分: 研究分担者

  • Design new fuels for heavy-duty diesel engines by 3D-CFD

    研究期間:

    2021年
     
     
     

    Jin Kusaka, Beini Zhou, Ratnak Sok

    担当区分: 研究分担者

  • MBD Approach to improve fuel economy of natural gas hybrid trucks

    研究期間:

    2018年
    -
    2021年
     

    Jin Kusaka, Ratnak Sok

    担当区分: 研究代表者

  • Improving 1D Combustion Simulation Accuracy for Gasoline Engines

    研究期間:

    2018年
    -
    2021年
     

    Jin Kusaka, Ratnak Sok, Kyohei Yamaguchi

    担当区分: 研究分担者

  • Machine Learning based MPC Controller Development for Diesel Engine Control

    研究期間:

    2018年
    -
    2021年
     

    Jin Kusaka, Kyohei Yamaguchi, Ratnak Sok, Beini Zhou

    担当区分: 研究分担者

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講演・口頭発表等 【 表示 / 非表示

  • Prediction of Potential Fuel Economy Improvements of an Electrified Natural Gas Truck Equipped With a VVT/VCR Engine

    Ratnak Sok, Jin Kusaka, Hisaharu Nakashima, Makoto Akaike, Hidetaka Minagata

    ASME 2021 International Mechanical Engineering Congress and Exposition  

    発表年月: 2021年11月

    開催年月:
    2021年11月
     
     
  • Experimental Investigation on the Effects of Direct Fuel Injection Into Low-O2 Recompression Interval of an HCCI Engine

    Ratnak Sok, Jin Kusaka

    ASME 2021 International Mechanical Engineering Congress and Exposition  

    発表年月: 2021年11月

    開催年月:
    2021年11月
     
     
  • Fast Nonlinear Model Predictive Control Using Machine Learning for Air Path Control of a Diesel Engine

    Kyohei Yamaguchi, Keisuke Yokota, Rio Asakawa, Iku Tanabe, Ratnak Sok, Beini Zhou, Jin Kusaka, Masatoshi Ogawa, Takuma Degawa, Shigeaki Kurita

    SAE Powertrains, Fuels & Lubricants Digital Summit  

    開催年月:
    2021年09月
     
     
  • A Model for Predicting Turbulent Burning Velocity by using Karlovitz Number and Markstein Number under EGR Conditions

    Kei Yoshimura, Kohei Ozawa, Kyohei Yamaguchi, Ratnak Sok, Jin Kusaka, Masaaki Togawa, Satoshi Tokuhara

    SAE Powertrains, Fuels & Lubricants Digital Summit  

    開催年月:
    2021年09月
     
     
  • Effects of Partial Oxidation in an Unburned Mixture on a Flame Stretch under EGR Conditions

    Kei Yoshimura, Kohei Ozawa, Kyohei Yamaguchi, Ratnak Sok, Jin Kusaka, Masaaki Togawa, Satoshi Tokuhara

    SAE Powertrains, Fuels & Lubricants Digital Summit  

    開催年月:
    2021年09月
     
     

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担当経験のある科目(授業) 【 表示 / 非表示

  • TA on Thermal energy reaction engineering

    早稲田大学  

    2018年
    -
    継続中
     

  • TA on Thermal energy reaction engineering

    早稲田大学  

    2012年
    -
    2015年
     

  • ICEs, GD&T Fundamentals, Material Sciences

    National Polytechnics Institute of Cambodia  

    2011年
    -
    2012年
     

  • ICEs, Machine elements, mechanical constructions

    Institut de Technologie du Cambodge  

    2011年
    -
    2012年