Rainer Haas, Bernhard Manhartsgruber,
"Compressibility and Thermo-Elasticity Measurements of a Hydraulic Fluid"
, in H. Sairiali and K. T. Koskinen: Proceedings of the Twelfth Scandinavian International Conference on Fluid Power, SICFP'11, May 18-20, 2011, Tampere, Finland, Vol. 2, Seite(n) 297-311, 5-2011, ISBN: 978-952-15-2519-3
Compressibility and Thermo-Elasticity Measurements of a Hydraulic Fluid
Sprache des Titels:
Proceedings of the Twelfth Scandinavian International Conference on Fluid Power, SICFP'11, May 18-20, 2011, Tampere, Finland
For a proper simulation of pulsations in the low pressure range it is very important have an adequate density law of the fluid. In order to get this knowledge, a test rig was built and first measurements were studied. These studies pointed out that it is very important for density identification, to take thermoelastic effects into account. For example a very fast compression of the fluid leads to heat production followed by an increase in pressure due to the heat expansion coefficient of the fluid. More generally the bulk modulus depends on the time constants of the change of its thermodynamic states.
A literature study on thermoelasticity showed that there is a lot of theoretical work done for solids, for ideal gases and fluids. The aim of this paper is to adopt this theory for an special experimental setup and to verify it by measurements. First some literature on this effect is shown followed by a discussion of the test rig and an exemplary measurement cycle. These measurements are compared to a theoretical model for thermoelasticity. Results and future improvements will be discussed.