ダクト内空気流れに導入された水噴霧質の移流速度に関する研究

抄録

An evaporative cooling system using ultrasonic vibrators has been proposed for the small centrifugal compressors in the micro gas turbine system, in order to decrease the compression work. The validity of the cooling system had been verified experimentally for the certain compressor. In order to clarify the extent of the validity of the system, a numerical analysis model is being constructed for the cooling system, which can be applied for various types of compressors. The present model simulates the evaporative cooling in the mist introducing duct (the inlet cooling), implying the physics of the advection and the diffusion of the mist, the vapor, the heat and the momentum of the air flow, as well as the evaporation. This paper shows the PIV measurement results of the advection velocity of the water mist introduced in the air flow duct, which can be used to verify and refine the numerical model. The results reveal the effects of the water columns produced by the ultrasonic vibrators, showing the deceleration of the longitudinal velocity in the near wake regions of the columns. Secondary flow component is found to change its distribution from the near wake to the far wake, which may bring large effects on the evaporative cooling in the inlet duct.