Roots형 과급기 로브 형상 변화가 성능에 미치는 영향

Effect of Lobe Shape Variations on the Performance of Roots-type Supercharger

A Computer program is developed for creation of a new lobe shaper for Roots-type supercharger. Numerical analyses are preformed for the flowfields in the pocket volumes formed by various lobe shapes. The governing equations for the two-dimensional, turbulent, operational processes in the housing are discretized by the control volume approach that insures the conservative characteristics to be satisfied in the calculation domain, and they are solved by a modified SIMPLE algorithm. Numerical results show that the effects of secondary flow on the leakage flow rate with the Cassini(B) lobe shape is smaller than that of Cassini(A) rotor. But the pocket volume of Cassine(B) lobe is larger than the other lobe shapes.