Search Results - "HAYAKAWA, Akihiro"

Science and technology of ammonia combustion by Kobayashi, Hideaki, Hayakawa, Akihiro, Somarathne, K.D. Kunkuma A., Okafor, Ekenechukwu C.

“…This paper focuses on the potential use of ammonia as a carbon-free fuel, and covers recent advances in the development of ammonia combustion technology and…”
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Laminar burning velocity and Markstein length of ammonia/air premixed flames at various pressures by Hayakawa, Akihiro, Goto, Takashi, Mimoto, Rentaro, Arakawa, Yoshiyuki, Kudo, Taku, Kobayashi, Hideaki

“…•Laminar burning velocities of ammonia/air flames at high pressures are evaluated.•Maximum value of laminar burning velocity of ammonia/air flame is about…”
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Experimental and numerical study of the laminar burning velocity of CH4–NH3–air premixed flames by Okafor, Ekenechukwu C., Naito, Yuji, Colson, Sophie, Ichikawa, Akinori, Kudo, Taku, Hayakawa, Akihiro, Kobayashi, Hideaki

“…With the renewed interest in ammonia as a carbon-neutral fuel, mixtures of ammonia and methane are also being considered as fuel. In order to develop gas…”
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Measurement of the laminar burning velocity and kinetics study of the importance of the hydrogen recovery mechanism of ammonia/hydrogen/air premixed flames by Gotama, Gabriel J., Hayakawa, Akihiro, Okafor, Ekenechukwu C., Kanoshima, Ryuhei, Hayashi, Masao, Kudo, Taku, Kobayashi, Hideaki

“…The application of ammonia (NH3) blended with hydrogen (H2) as a fuel in combustion systems is a practical approach to decarbonise the energy sector, and the…”
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Burning velocity and flame structure of CH4/NH3/air turbulent premixed flames at high pressure by Ichikawa, Akinori, Naito, Yuji, Hayakawa, Akihiro, Kudo, Taku, Kobayashi, Hideaki

“…Ammonia is one of the most promising alternative fuels. In particular, ammonia combustion for gas turbine combustors for power generation is expected. To shift…”
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Experimental investigation of stabilization and emission characteristics of ammonia/air premixed flames in a swirl combustor by Hayakawa, Akihiro, Arakawa, Yoshiyuki, Mimoto, Rentaro, Somarathne, K.D. Kunkuma A., Kudo, Taku, Kobayashi, Hideaki

“…Ammonia is a possible candidate for use as a hydrogen energy carrier as well as a carbon-free fuel. In this study, flame stability and emission characteristics…”
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Laminar burning velocity and Markstein length of ammonia/hydrogen/air premixed flames at elevated pressures by Ichikawa, Akinori, Hayakawa, Akihiro, Kitagawa, Yuichi, Kunkuma Amila Somarathne, K.D., Kudo, Taku, Kobayashi, Hideaki

“…Ammonia shows promise not only as a hydrogen-energy carrier but also as a carbon-free fuel. However, combustion intensity of ammonia must be improved to enable…”
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Effects of initial mixture temperature and pressure on laminar burning velocity and Markstein length of ammonia/air premixed laminar flames by Kanoshima, Ryuhei, Hayakawa, Akihiro, Kudo, Takahiro, Okafor, Ekenechukwu C., Colson, Sophie, Ichikawa, Akinori, Kudo, Taku, Kobayashi, Hideaki

“…•Laminar burning velocities of ammonia/air flames at high temperatures and pressures.•Temperature exponents of ammonia flames were larger than those of methane…”
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Towards the development of an efficient low-NOx ammonia combustor for a micro gas turbine by Okafor, Ekenechukwu C., Somarathne, K.D. Kunkuma A., Hayakawa, Akihiro, Kudo, Taku, Kurata, Osamu, Iki, Norihiko, Kobayashi, Hideaki

“…Recent studies have demonstrated stable generation of power from pure ammonia combustion in a micro gas turbine (MGT) with a high combustion efficiency, thus…”
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Extinction limits of an ammonia/air flame propagating in a turbulent field by Ichimura, Ryo, Hadi, Khalid, Hashimoto, Nozomu, Hayakawa, Akihiro, Kobayashi, Hideaki, Fujita, Osamu

“…•We conduct spherical flame propagation experiments of ammonia/air mixture in a turbulent field.•Effects of turbulence intensity and equivalence ratio on…”
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Effects of Water Vapor Dilution on the Laminar Burning Velocity and Markstein Length of Ammonia/Water Vapor/Air Premixed Laminar Flames by Hayashi, Masao, Hayakawa, Akihiro, Kudo, Taku, Kobayashi, Hideaki

“…Since the Industrial Revolution, large amounts of ammonia have been synthesized by the Haber–Bosch process and used as fertilizer and chemical materials…”
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Experimental and numerical study of product gas characteristics of ammonia/air premixed laminar flames stabilized in a stagnation flow by Hayakawa, Akihiro, Hirano, Yuta, Okafor, Ekenechukwu C., Yamashita, Hirofumi, Kudo, Taku, Kobayashi, Hideaki

“…Ammonia has widely attracted interest as a potential candidate not only as a hydrogen energy carrier but also as a carbon free fuel for internal combustion…”
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Emission characteristics of turbulent non-premixed ammonia/air and methane/air swirl flames through a rich-lean combustor under various wall thermal boundary conditions at high pressure by Somarathne, Kapuruge Don Kunkuma Amila, C. Okafor, Ekenechukwu, Hayakawa, Akihiro, Kudo, Taku, Kurata, Osamu, Iki, Norihiko, Kobayashi, Hideaki

“…This study is dedicated to understanding the combustion and emission characteristics of turbulent non-premixed ammonia (NH3)/air and methane (CH4)/air swirl…”
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Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation by Kurata, Osamu, Iki, Norihiko, Inoue, Takahiro, Matsunuma, Takayuki, Tsujimura, Taku, Furutani, Hirohide, Kawano, Masato, Arai, Keisuke, Okafor, Ekenechukwu Chijioke, Hayakawa, Akihiro, Kobayashi, Hideaki

“…Low-NOx NH3-air combustion power generation technology was developed by using a 50-kWe class micro gas-turbine system at the National Institute of Advanced…”
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Investigation of bimodal characteristics of the droplet size distribution in condensation spray by Okajima, Junnosuke, Kato, Mitsuki, Hayakawa, Akihiro, Iga, Yuka

“…To understand the generation process of airborne droplets during exhalation, this study investigates the mechanism of bimodal characteristics of the size…”
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Stabilization mechanisms of an ammonia/methane non-premixed jet flame up to liftoff by Colson, Sophie, Kuhni, Manuel, Hayakawa, Akihiro, Kobayashi, Hideaki, Galizzi, Cédric, Escudié, Dany

“…Ammonia is a promising alternative fuel for CO2 emission mitigation. The use of ammonia blends allows for more flexibility compared to pure ammonia fuel and is…”
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Study on the effect of injection temperature and nozzle geometry on the flashing transition of liquid ammonia spray by Colson, Sophie, Yamashita, Hirofumi, Oku, Kohei, Somarathne, Kapuruge Don Kunkuma Amila, Kudo, Taku, Hayakawa, Akihiro, Kobayashi, Hideaki

“…•The transition to flashing was observed for liquid ammonia.•Existing criteria approximated flashing transition but did not catch geometry effect.•Spray angles…”
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Effects of hydrogen concentration on premixed laminar flames of hydrogen–methane–air by Okafor, Ekenechukwu C., Hayakawa, Akihiro, Nagano, Yukihide, Kitagawa, Toshiaki

“…The unstretched laminar burning velocities and Markstein numbers of spherically propagating hydrogen–methane–air flames were studied at a mixture pressure of…”
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NO formation/reduction mechanisms of ammonia/air premixed flames at various equivalence ratios and pressures by HAYAKAWA, Akihiro, GOTO, Takashi, MIMOTO, Rentaro, KUDO, Taku, KOBAYASHI, Hideaki

“…Ammonia is a carbon-free fuel and its application to internal combustion engines is expected. However, few studies on ammonia flames, especially at high…”
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Liquid ammonia spray combustion in two-stage micro gas turbine combustors at 0.25 MPa; Relevance of combustion enhancement to flame stability and NOx control by Okafor, Ekenechukwu C., Kurata, Osamu, Yamashita, Hirofumi, Inoue, Takahiro, Tsujimura, Taku, Iki, Norihiko, Hayakawa, Akihiro, Ito, Shintaro, Uchida, Masahiro, Kobayashi, Hideaki

“…•1st study of LNH3 spray combustion at actual micro gas turbine operating conditions.•Novel combustors with and without wall cooling were developed and…”
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