Vibration Of Hydraulic Machinery

Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration prediction of hydraulic machinery.

This volume is concerned with vibration-free and quiet operation of hydraulic machines. It deals with the problems caused by mechanical and hydraulic excitations in hydraulic machinery (except for transients which are treated in a separate volume). The invited authors from five continents are internationally recognized experts in their fields. The book looks at the fundamentals for analysis of fluid structure systems, structural vibration, shaft rotordynamics and system instability; noise and diagnosis are introduced with examples from practical experience.

The subject of this book is to examine the influence of mechanical vibration on the changes in the pressure pulsation spectrum of hydraulic systems. In book shows that machines and equipment equipped with hydraulic systems are a source of vibration with a wide frequency spectrum. Additionally, hydraulic valves are also exposed to vibration. Vibrations of the substrate on which the hydraulic valve is installed force the control element of the hydraulic valve to vibrate. The control element's vibration produced in this way causes changes in the pressure pulsation spectrum of the hydraulic system. A friction model modified using mixed friction theory can be used for the oscillating motion of the hydraulic directional control spool. Passive vibration isolation methods are proposed to reduce valve vibration. The biomimetic approach can be implemented in hydraulic systems (for pipelines) to reduce mechanical vibration and fluid pulsation. Numerical methods are employed to analyze the effect of changes in the pressure pulsation spectrum on the hydraulic efficiency of the pipelines. Examples are provided for the implementation of numerical methods in the calculation of hydraulic components and systems. Additionally, the effects of energy-saving in hydraulic systems by applying the proposed results overview in the current book. The current book will be interesting for both–scientific and manufacturing staff, since the implementation of knowledge can help to design more substantiable construction of machine hydraulic systems to avoid vibration problems.

Since the 1970’s, an increasing amount of specialized research has focused on the problems created by instability of internal flow in hydroelectric power plants. However, progress in this field is hampered by the interdisciplinary nature of the subject, between fluid mechanics, structural mechanics and hydraulic transients. Flow-induced Pulsation and Vibration in Hydroelectric Machinery provides a compact guidebook explaining the many different underlying physical mechanisms and their possible effects. Typical phenomena are described to assist in the proper diagnosis of problems and various key strategies for solution are compared and considered with support from practical experience and real-life examples. The link between state-of the-art CFD computation and notorious practical problems is discussed and quantitative data is provided on normal levels of vibration and pulsation so realistic limits can be set for future projects. Current projects are also addressed as the possibilities and limitations of reduced-scale model tests for prediction of prototype performance are explained. Engineers and project planners struggling with the practical problems will find Flow-induced Pulsation and Vibration in Hydroelectric Machinery to be a comprehensive and convenient reference covering key topics and ideas across a range of relevant disciplines.

This book focuses on hydraulic components and machines, and illustrates how a machine's noise-radiating surfaces affect noise. It reviews the basics and terminology of sound, vibration, vibration isolation, fluid pulsations, Fourier analysis, cavitation, hydraulic shock, and enclosure design.

Hydraulic machinery such as turbines and pumps is widely used around the world. Related topics concerning design, operation and maintenance are of relevant interest. In this context, cavitation is a phenomenon to be taken into account, and this was treated in the XVIII IAHR Symposium on Hydraulic Machinery and Cavitation which took place in Valencia, Spain, 16th-19th September, 1996 and which was hosted by the Polytechnic University of Valencia. The proceedings of the Symposium have been published in two volumes. In this first volume, the papers included cover the following topics: Hydraulic Turbines, Analysis and Design Hydraulic Pumps Hydraulic Elements, Dynamic Characterization and Hydraulic Behaviour Cavitation and Sand Erosion In the second volume, the papers included cover the following topics: Hydraulic Transients and Control Systems Related to Hydraulic Machinery and Plants Oscillatory and Vibration Problems in Hydraulic Machinery and Power Stations Experimental Investigations related to Hydraulic Machinery and its Applications Practical Applications of the Hydraulic Machinery Monitoring, Predictive Maintenance and Refurbishment The 119 papers presented at the Symposium, from research groups, consulting companies and manufacturers, constitute an important collection for investigators, engineers and technicians who are interested in updated information on hydraulic machinery. This book is intended to be a reference text comprising the latest innovations on this subject.