Takashi Niioka

TL;DR: In this paper, the effects of ambient pressures on the turbulent burning velocity in a high-pressure environment, turbulent premixed flames of lean methane-air mixtures stabilized with a nozzle-type burner, were investigated experimentally, and it was found that the region of wave numbers where the flame front is unstable extends to larger wave numbers with increasing pressure.

TL;DR: In this paper, the effects of ambient pressure on turbulence characteristics and possible mechanisms which produce the wrinkled structure of the fine scales and generate flame front disturbances in the high-pressure environment are discussed.

TL;DR: In this article, the extinction of counterflow diffusion flames of air and methane diluted with nitrogen was studied by drop tower experiments and numerical calculation using detailed chemistry and transport properties, and the mechanism of extinction at low stretch rates was radiative heat loss from the flame zone.

TL;DR: In this article, particle tracking velocimetry (PTV) and image processing for burner-stabilized flames in a high-pressure chamber were performed. And the experimental and numerical results agreed reasonably well with each other for mixtures of equivalence ratios of 1.0 and 2.0.

TL;DR: In this paper, the authors used numerical methods, including are-length continuation, to simulate the extinction characteristics of counterflow premixed fuel-lean, methane-air flames, and found that at medium to low values of the stretch rate, radiative heat loss has a particularly strong impact on the extinction of these flames.