Fluidyne engine

Abstract: Liquid piston Stirling engines (sometimes termed “fluidynes”) have been studied extensively and applied in a variety of energy conversion applications. They are attractive for low capital costs and simplicity of construction. In addition, their operation as external combustion engines allows for flexibility in primary energy sources which is a distinct advantage when a low-cost or free source of heat can be paired with their minimal construction costs. Disadvantages of these devices include relatively low efficiency and low power density. A solar-powered fluidyne test bed was constructed and operated at the University of Colorado at Colorado Springs. This test bed was composed of a fluidyne engine which was constructed from copper pipe and plastic tubing along with temperature and pressure instrumentation. The system was designed to be powered by a Fresnel lens concentrating solar energy. The concentrated solar energy from the Fresnel lens provided ample power to operate the test bed, and tests were run in a wide variety of conditions. Indicated work of this unloaded engine was shown to agree well with a simple theoretical model of a Stirling cycle.Copyright © 2011 by ASME

Abstract: Previous works related to this thesis revolves around the construction and experimental testings of a prototype wooden engine and a fruit jar engine of West’s engines. Currently, no Fluidyne engines are available in the University of Queensland. Thus, the construction of a new design is required for further experimental works in this field of study. This thesis involves the investigation of the pumping capability of an experimental fluidyne engine. The engine was designed to be soft coupled to a pump and tested under wet mode conditions. Material selections and cost considerations were some key factors during the construction phase of the engine. During the experimental phase, the Fluidyne was able to perform reasonably well. However, a leakage was found at the seating of the ball bearing of a non-return valve incorporated to the pump line. Water inside the pumping arm flows back into the pail through the leakage. Thus, the pump did not work. Discussions of some of the findings from the results were presented. This thesis ends with a conclusion and some recommendations.

Abstract: The Fluidyne is a two-part hot-air engine, which has the peculiarity that both its power piston and displacer are liquids. Both parts operate in tandem with the common working gas (air) transferring energy from the displacer to the piston side, from which work is extracted. We describe analytically the thermodynamics of the Fluidyne engine using the approach previously developed for the Stirling engine. We obtain explicit expressions for the amplitude of the power piston movement and for the working gas temperatures and pressure as functions of the engine parameters. We also study numerically the power and efficiency of the engine in terms of the phase shift between the motions of piston and displacer.

Abstract: FIELD: heat power industry, installations operating in accord with Sterling cycle. SUBSTANCE: stable uninterrupted operations of engine 1 with feed of heat to space 7 is provided with the aid of principle of jet stream. As result of operation of engine 1 cyclic variation of volume and pressure of working medium ( gas ) takes place in spaces 6, 7 and conduit 5 that leads to forced oscillations of liquid columns in cold tube 2, hot tube 3 and cone-shaped outlet tube 4. . Conicity of tube 4 makes it feasible to obtain higher rise of liquid level and increased pressure of liquid in end 8 bent through 180 degrees and connected to chamber 9. Liquid under high pressure falls on blades 14 of turbine 13 and sets it in rotation transmitted via shaft 12 to user of mechanical or electric energy. Constant amount of liquid in engine 1 is maintained with the aid of U-shaped tube 11. EFFECT: improved efficiency of conversion of oscillations of working media of engine to useful mechanical or electric energy. 1 dwg