LDV(laser Doppler velocimetry) measurements were conducted on the exit region of the impeller passage and the gap between the impeller and turbine blades under 0.8 speed ratio. The 0.8 speed ratio has an impeller speed of 2000rpm and a turbine speed of 1600rpm. A periodic variation of the mass flow rate is present in many of the measurements made. The frequency of this variation is the same as the frequency of the turbine blades passing the impeller passage exit. It is found that the instantaneous position of the turbine had effect on fluid flow inside the impeller passage and gap region. This study would aid in the construction of higher accuracy CFD models of this complex turbomachinery device.

ABSTRACT
 1. 서 론
 2. 실험장치 및 방법
  2.1 실험장치의 구성
  2.2 레이저 도플러 유속계 관측창
  2.3 실험절차
 3. 결과 및 고찰
 4. 결 론
 References

• 유성출(Department of mechanical and automotive engineering of Halla University) | S. C. Yoo Corresponding Author