SPECIAL DOUBLE-HEADER SEMINAR
Speaker: Prof. Yulin Wu (Tsinghua University)
Title: "Cavitation Evolution and Excited Pressure Fluctuation around Twisted Hydrofoils and Marine Propellers by CFD Analysis"
Date: Monday, January 14, 2013
Time: 11:00 a.m.
Location: Gilman Hall 50 (Marjorie M. Fisher Hall)
Cavitation phenomena consists of a complex combination of fluid dynamics and bubble/cavity mechanics. Therefore by unsteady nature, cavitation can significantly induce hydrodynamics performance pulsation and pressure fluctuations. In order to gain a better understanding of the complex physics involved, unsteady cavitating flow simulation around twisted hydrofoils and marine propellers were carried out by CFD analysis.
Twisted hydrofoil was selected to study 3D cavitating flow structures for some operating conditions. We also studied unsteady cavitating flow around marine propellers in non-uniform wake. The results described in both cases were intended to shed light on the physics process responsible for the pressure fluctuation excited by the cavitation evolution (lower frequency component only). We related the cavitation evolution, especially cavity volume, to the pressure fluctuations.
The results show that the acceleration due to the cavity volume change is the main source of the pressure fluctuations are excited by cavitating hydrofoils and marine propellers. Some recent work about the interaction between fluid turbulence and cavitation was carried out by our group. Our work was based on CFD simulation and some preliminary results agreed with experimental results (Gopalan and Katz, 2000).