Positive Displacement Machines

Modern Design Innovations and Tools

Ibrahim A. Sultan, Truong H. Phung

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128169988
• eBook ISBN: 9780128169995
• Topic: Technology & Engineering
• Subtopic: Fluid Mechanics
• Index: Technology & Engineering

Positive Displacement Machines: Modern Design Innovations and Tools explains the design and workings of a wide range of positive displacement pumps, compressors and gas expanders. Written at a mathematical and technical level, the book explores the most influential research in this field over the past decade, along with industry best practices. Sections highlight the importance of using the latest computation techniques and discuss how to follow the proper design procedures to achieve a desired outcome. - Explains how these machines work on a fundamental level, helping the reader build a holistic understanding which aids complex problem- solving - Describes how to mathematically model the performance of pumps, compressors and gas expanders - Provides advice on how to design and optimize positive displacement machines to match a given application

Part 1

Geometric innovation in positive displacement machines

Chapter 1

The orbital displacer: Implications and applications

Ian James Spark^a,b; Kui Lu^{c a} School of Science, Engineering and IT, Federation University Australia, Churchill, VIC, Australia
^b Centre for Informatics and Applied Optimisation, Federation University Australia, Mount Helen, VIC, Australia
^c School of Science, Engineering and IT, Federation University Australia, Ballarat, VIC, Australia

Abstract

The significance of the orbital displacer may well extend well beyond its application as the basis of a four-stroke internal combustion engine. For example, its inherently high swept volume to total volume ratio can be further increased by combining the original orbital displacer with an everted (i.e. inside-out) orbital displacer to form a hybrid orbital displacer with an even higher swept volume to total volume ratio. Furthermore, the orbital motion of the piston can be used to open and close ports to produce any desired port timing with the same frequency as the orbiting of the piston. These together with other pertinent features will be considered under the following headings: 1. Introduction, 2. Swept volume to total volume ratio, 3. Working volume as a function of crank angle, 4. Minimum geometrically necessary clearance volume as a function of displacer geometry, 5. Valveless port timing, 6. Support of the orbiting piston and vanes, 7. Balancing of the orbital piston and vanes, 8. Sealing of the working volume, 9. Frictional losses and lubrication, 10. Combustion in orbital displacers, 11. Cooling of orbital engines, 12. Manufacturing processes and materials. The above pertinent features will be discussed with reference to the following applications of the orbital displacer: orbital two-stroke engine, orbital hydraulic pumps and motors, orbital pneumatic compressors and motors, orbital Rankine (steam) engine, and orbital 6 cc model aircraft engine. Engineering students have found orbital displacer projects stimulating in the originality required, as they invariably had to go back to first principles to solve problems.

Keywords

Positive displacement machine; Orbital displacer; Orbital piston; Port timing; Swept volume; Volume ratio

Contents

• Introduction
• Swept volume to total volume ratio
• Working volume as a function of crank angle
• Minimum geometrically necessary clearance volume (and maximum compression ratio) as a function of displacer geometry
• Valveless port timing
• Support of the orbiting piston and vanes
• Balancing of the orbital piston and vanes
• Sealing of the working volume
• Frictional losses and lubrication
• Combustion in orbital displacers
• Cooling of orbital engines
• Manufacturing processes and materials
• Conclusions
• Acknowledgements
• References

Acknowledgements

The authors would like to thank the staff and students of the Gippsland School of Engineering (now part of Federation University Australia) for their contrib...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Introduction
• Part 1: Geometric innovation in positive displacement machines
• Part 2: Mechanism analysis for positive displacement machines
• Part 3: Tools for analysis: Mathematical modelling and CFD
• Index