by Yulin Wu (Tsinghua University, China)

Concern about vibration is a major subject today since it has a major effect on the performance of hydraulic machinery. In the last ten years, the progress on theory, modeling and mathematical analysis, as well as monitoring of hydraulic machinery vibration has been tremendous. With hydraulic turbine capacities getting increasingly larger and pump speeds ever higher, there have been many research achievements in these areas published in symposiums, journals and books.

Vibration and Oscillation of Hydraulic Machinery covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods. The mechanical and hydraulic excitations to the vibration will be analyzed, and the pressure fluctuations induced by the unsteady turbulent flow will be predicted in order to get and obtain the unsteady loads. Upon obtaining the information of loads, constraint conditions and the elastic and dimpling characters of the mechanical system, the structure dynamic analysis and the rotor dynamic analysis and the system instability of hydraulic machines are reviewed and described, including the illustration of monitoring system for the instability and the vibration in hydraulic units.