Research and Technical Trend in Nuclear Fusion in Japan

As the population of the world is growing rapidly, the demand for energy that is clean and efficient is increasing. Combustion is one of the major ways of energy conversion that produces very high amount of pollutant emission, as such the research arena has been taken over by coming up with combustion processes that are cleaner and efficient by the combustion engineers. Flameless combustion is one of the new techniques discovered by researchers to suppress NOx emission due to the low temperature inside the combustion zone that is well below the dissociation temperature of Nitrogen. Homogenous or proper mixing is another major factor that enhances combustion efficiency. An asymmetric swirling combustor is a unique shaped combustor that was developed by researchers in order to enhance better mixing inside the combustion zone without the need for an external swirler. The review investigated several parameters such as temperature uniformity, fuel flexibility and level of pollutant emission as discussed by researchers and it was found that the asymmetric swirling combustor is very efficient with temperature uniformity of about 0.9, thermal efficiency of 53% and very low NOx and CO of about 2ppm and 24ppm according to researchers. It was recommended that the combustor should be investigated under different flow configurations i.e. forward and reverse flow in order to know the optimum direction of flow for the asymmetric swirling combustor.

Section: Fundamentals Of Swirlingmentioning

confidence: 99%

A Review on the Combustion Characteristics of an Asymmetric Swirling Combustor in Flameless Mode

Najib Aminu Ismail,

Mazlan Abdul Wahid,

Sa’at

et al. 2023

“…In the time of dwindling fuel resources, heavy emphasis are being put on sustainability and improving efficiency 1,2) . Organizations throughout the world are focusing on obtaining methods to reduce the consumption of fuel 3) .…”

Section: Introductionmentioning

confidence: 99%

Initiation Characteristics of Rotating Supersonic Combustion Engine

Mazlan¹,

Yasin²,

Saat³

et al. 2021

A rotating supersonic combustion engine (RSCE) is tested with various initiator tube positions along the combustion chamber to determine its impact on the ignition process. The type of fuel used is methane with oxygen as the oxidizer. The initiation of RSCE is assessed for nearstoichiometric methane-oxygen mixture to slightly rich mixture. Successful initiation of rotating supersonic combustion in the RSCE was obtained when the position of the initiator tube is located higher end of the combustion chamber that indicates a proper mixing of reactants. The mixing of reactants improves further up the annulus chamber of the RSCE.

“…Global warming, fossil fuel depletion, and excessive CO2 emission have urged the development of green alternative power sources such as wind, solar, geothermal energy, etc [1][2][3][4] . Another direction to tackle the energy crisis is improving the efficiency of power usage through waste-heat recovery.…”

Section: Introductionmentioning

confidence: 99%

Rapid Synthesis of W_18O_49 via Reactive Spark Plasma Sintering with Controlled Anisotropic Thermoelectric Properties

Tran¹,

Ohtaki²,

Suekuni³

2021

Single phase W18O49 sintered polycrystalline samples were successfully synthesized via one-step rapid reactive spark plasma sintering directly from commercially purchased WO3 and WO2 powders. Thermoelectric properties of the samples sintered at 15 and 30 MPa showed insignificant anisotropy, while a strong anisotropy was observed for the sample sintered at 50 MPa. The in-situ reaction under a high applied pressure allowed a preferential grain growth along the direction perpendicular to the pressure axis. The high anisotropy of the sample sintered at 50 MPa yielded the lowest thermal conductivity of 4 Wm −1 K −1 , resulting in a ZT value of 0.08 at 1073 K. This study offers the rapid and cost-effective preparation method for W18O49 materials, which can also be applied for other tungsten suboxide phases, with partially controlled anisotropic properties by the influence of applied pressure for thermoelectric performance enhancement.