1st Edition

Hydraulic Power System Analysis

By Arthur Akers, Max Gassman, Richard Smith Copyright 2006
    400 Pages 137 B/W Illustrations
    by CRC Press

    The excitement and the glitz of mechatronics has shifted the engineering community’s attention away from fluid power systems in recent years. However, fluid power still remains advantageous in many applications compared to electrical or mechanical power transmission methods. Designers are left with few practical resources to help in the design and analysis of fluid power systems, especially when approaching fluid power for the first time.

    Helping you overcome these hurdles, Hydraulic Power System Analysis demonstrates modern computer-aided analytical techniques used to model nonlinear, dynamic fluid power systems. Following an overview of fluid power, the authors examine various relevant fluid properties, energy calculations, and steady state and dynamic analysis along with a review of automatic control theory. Turning to modeling, the next few chapters address valves and motors and then apply dynamic modeling to examples relating to pumps, hydrostatic transmissions, and valves. The book includes a unique chapter showing how to combine flow resistance equations with the differential equations governing dynamic system performance. The final chapter translates electrical circuit theory concepts to noise attenuation in fluid power systems.

    Illustrated with many equations, practical computer modeling examples, and exercises, Hydraulic Power System Analysis provides a much-needed modernization of dynamic modeling for fluid power systems using powerful computational tools.

    What Is Fluid Power?
    A Brief History of Fluid Power
    Fluid Power Applications, Present and Future
    Advantages of Using Fluid Power Systems
    A Probable Future Development
    Properties of Fluids and Their Units
    Basic Properties of Fluids
    Compressibility of Liquids
    Steady State Modeling
    Rationale for Model Development
    Source of Equations
    Conservation of Flow and Energy
    Friction Losses in Pipes and Fittings
    Basic Component Equations
    Worked Examples
    Dynamic Modeling
    Development of Analytical Methods
    Software Options
    Dynamic Effects
    Worked Examples
    Modeling Hints and Tips
    Linear Systems Analysis
    Linear Systems
    The Laplace Transform
    Inversion, the Heaviside Expansion Method
    Block Diagrams
    Spring-Mass-Damper Time Response to Unit Step Force
    Time Constant
    Frequency Response and Feedback
    Mathematics of Frequency Response
    Frequency Response Diagrams
    Using Frequency Response to Find Controller Gain
    Valves and Their Uses
    Directional Control Valves
    Special Directional Control Valves, Regeneration
    Flapper Nozzle Valve
    Flow Control Elements
    Relief Valves
    Unloading Valve
    Pressure Reducing Valve
    Pressure Sequencing Valve
    Counterbalance Valve
    Flow Regulator Valve
    Pumps and Motors
    Configuration of Pumps and Motors
    Pump and Motor Analysis
    Form of Characteristic Curves
    Axial Piston Pumps and Motors
    Pressure During a Transition
    Torque Affected by Pressure Transition — Axial Piston Pump
    Torque and Flow Variation with Angle for Multicylinder Pumps
    Hydrostatic Transmissions
    Performance Envelope
    Hydrostatic Transmission Physical Features
    Hydrostatic Transmission Dynamic Analysis
    Pressure Regulating Valve
    Purpose of Valve
    Operation of Valve
    Mathematical Model of Valve
    Effect of Damping
    Valve Model Expansion
    Basic Valve Model
    Model Expansion
    An Assessment of Modeling
    Flow Division
    The Hydraulic Ohm Method
    Brief Review of DC Electrical Circuit Analysis
    Fluid Power Circuit Basic Relationships
    Consolidation of Fluid Power Resistances
    Application to Unsteady State Flow
    Noise Control
    Discussion of Method
    Mathematical Model
    Effect of Entrained Air in Fluid
    Further Discussion of the Mathematical Model
    Other Methods of Noise Control
    Damping Methods


    Arthur Akers, Max Gassman, Richard Smith