Hironobu Ueki

TL;DR: In this article, the authors predicted the pressure recovery of a low-solidity circular cascade diffuser of a centrifugal blower by a simple method combining a theory of circular cascade and that of vaneless diffusers and compared with a series of experiments.

TL;DR: In this paper, the authors presented a theory that the tip clearance loss of an unshrouded centrifugal impeller mainly consists of two kinds of loss; one is the drag due to the leakage flow through the blade tip clearance and the other is the pressure loss to support the fluid in the thin annular clearance space between the shroud and the tip against the pressure gradient in the meridional plane without blades.

TL;DR: In this article, the authors applied the ring groove arrangement to the high speed centrifugal compressor, in order to suppress too large pre-whirl due to the recirculation flow, the effects of guide vane installed in the annular passage and the ring-groove configuration on the prewhirl were analyzed numerically, and simulation results show the multi-ring grooves are fairly effective in combination with the suitable configuration of guide vanes for improvement in the inlet velocity distortion.

TL;DR: In this paper, the IR two-color method was applied to the measured radiant energy from the soot particles in a steady turbulent diffusion flame of propane by using the semiconductor laser 2-focus velocimeter and the optical fiber thermometer, and it was shown that the time mean value and the fluctuation of the flame temperature decrease gradually toward downstream in the luminous flame region, and those of soot density increase due to decay of turbulence along the flame axis.

TL;DR: In this article, the authors presented a theory that the tip clearance loss of an unshrouded centrifugal impeller mainly consists of two kinds of loss; one is the drag due to the leakage flow through the blade tip clearance and the other is the pressure loss to support the fluid in the thin annular clearance space between the shroud and the tip against the pressure gradient in the meridional plane without blades.