Strength of the Blower with Straight Impeller for High-Supercharging

Abstract

For high-supercharging of diesel engines, we planned a blower with straight impeller of the radial type which we have never used before. The circumferential design speed of the impeller of this type is much higher than that of the ordinary impeller. Therefore, in order to confirm the strength of the impeller, we have theoretically analyzed the stress, using the digital computer and on the other hand we have experimentally analyzed the stress by stress freezing by revolution for the three dimensional photoelastic model. Thus, by clearly knowing the stress distribution in the blade and the disc, we could confirm the reliability of the impeller of the radial type. Also, from the view-point of the limit design, we could presume that the bursting-speed would be 30 000 rpm, which corresponds to 100% over-speed.