Measuring Pressure Wave Velocity in a Hydraulic System

Authors: Lari Kela, Pekka Vähäoja

Abstract:

Pressure wave velocity in a hydraulic system was determined using piezo pressure sensors without removing fluid from the system. The measurements were carried out in a low pressure range (0.2 – 6 bar) and the results were compared with the results of other studies. This method is not as accurate as measurement with separate measurement equipment, but the fluid is in the actual machine the whole time and the effect of air is taken into consideration if air is present in the system. The amount of air is estimated by calculations and comparisons between other studies. This measurement equipment can also be installed in an existing machine and it can be programmed so that it measures in real time. Thus, it could be used e.g. to control dampers.

Keywords: Bulk modulus, pressure wave, sound velocity.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1080526

References:

[1] E. H├©gseth, G. Hedwig, and H. H├©iland, "Rubidium clock sound velocity meter," Rev. Sci. Instrum., vol. 71, no. 12, pp. 4679-4680, 2000.
[2] G. Meng, A. J. Jaworski, and N. M. White, "Composition measurements of crude oil and process water emulsions using thick-film ultrasonic transducers," Chem. Eng. Process., vol. 45, pp. 383-391, 2006.
[3] B. Lagourette, and J. L. Daridon, "Speed of sound, density and compressibility of petroleum fractions from ultrasonic measurements under pressure," J. Chem. Thermodyn., vol. 31, pp. 987-1000, 1999.
[4] C. González, J. M. Resa, J. Lanz, and A. M. Fanega, "Speed of sound and isentropic compressibility of organic solvents + sunflower oil mixtures at 298.15 K," JAOCS, vol. 79, no. 6, pp. 543-548, 2002.
[5] S. J. Ball, A. R. H. Goodwin, and J. P. M. Trusler, "Phase behavior and physical properties of petroleum reservoir fluids from acoustic measurements," J. Petrol. Sci. Eng., vol. 34, pp. 1-11, 2002.
[6] H. S. Song, E. E. Klaus, and J. L. Duda, "Prediction of bulk moduli for mineral oil based lubricants, polymer solutions, and several classes of synthetic fluids," J. Tribol. -T. ASME, vol. 113, pp. 675-680, October 1991.
[7] C. Aparicio, B. Guignon, L. M. Rodríguez-Antón, and P. D. Sanz, "Determination of rapeseed methyl ester oil volumetric properties in high pressure (0.1 to 350 MPa)," J. Therm. Anal. Calorim., vol. 89, pp. 13-19, 2007.
[8] J. Kajaste, H. Kauranne, A. Ellman, and M. Pietola, "Experimental validation of different models for bulk modulus of hydraulic fluid," in Proc. 9th Scandinavian Int. Conf. on Fluid Power, SICFP`05, Linköping, Sweden, 2005, 16 p.
[9] J. Kajaste, H. Kauranne, A. Ellman, and M. Pietola, "Computational models for effective bulk modulus of hydraulic fluid," in Proc. 2nd Int. Conf. Computational Methods in Fluid Power, FPNI`06, Aalborg, Denmark, 2006, 7 p.
[10] H. - H. Harms, and D. Prinke, "Messverfahren zur Bestimmung der Schallgeschwindigkeit in Mineralölen," o+p ölhydraulik und pneumatik, vol. 23, no. 3, pp. 191-194, 1979. In German.
[11] B. - H. Cho, H. - W. Lee, and J. - S. Oh, "Estimation technique of air content in automatic transmission fluid by measuring effective bulk modulus," Int. J. Automot. Techn., vol. 3, no. 2, pp. 57-61, 2002.
[12] J. Yu, Z. Chen, and Y. Lu, "The variation of oil effective bulk modulus with pressure in hydraulic systems," J. Dyn. Systems - T. ASME, vol. 116, pp. 146-150, March 1994.
[13] R. E. Apfel, "Technique for measuring the adiabatic compressibility, density, and sound speed of submicroliter liquid samples," J. Acoust. Soc. Am., vol. 59, no. 2, pp. 339-343, 1976.
[14] R. E. Apfel, R. E. Young, U. Varanasi, J. R. Maloney, and D. C. Malins, "Sound velocity in lipids, oils, waxes, and their mixtures using an acoustic levitation technique," J. Acoust. Soc. Am,. vol. 78, no. 3, pp. 868-870, 1985.
[15] M. E. Tat, J. H. Van Gerpen, S. Soylu, M. Canakci, A. Monyem, and S. Wormley, "The speed of sound and isentropic bulk modulus of biodiesel at 21 ┬░C from atmospheric pressure to 35 MPa," JAOCS, vol. 77, no. 3, pp. 285-289, 2000.
[16] M. E. Tat, and J. H. Van Gerpen, "Speed of sound and isentropic bulk modulus of alkyl monoesters at elevated temperatures and pressures," JAOCS, vol. 80, no. 12, pp. 1249-1256, 2003.
[17] M. Dzida, and P. Prusakiewicz, "The effect of temperature and pressure on the physicochemical properties of petroleum diesel oil and biodiesel fuel," Fuel, 2007, doi:10.1016/j.fuel.2007.10.010.
[18] F. Maleky, R. Campos, and A. G. Marangoni, "Structural and mechanical properties of fats quantified by ultrasonics," J. Amer. Oil. Chem. Soc., vol. 84, pp. 331-338, 2007.
[19] J. Kim, and K. - M. Park, "Material characterization of MR fluid at high frequencies," J. Sound Vib., vol. 283, pp. 121-133, 2005.
[20] A. L. Boehman, D. Morris, J. Szybist, and E. Esen, "The impact of the bulk modulus of diesel fuels on fuel injection timing," Energ. Fuel., vol. 18, pp. 1877-1882, 2004.
[21] L. E. Kinsler, A. R. Frey, A. B. Coppens, and J. V. Sanders, Fundamentals of acoustics. 3rd ed., USA: John Wiley & Sons, 1982.
[22] N. D. Manring, "The effective fluid bulk-modulus within a hydrostatic transmission," J. Dyn. Systems - T. ASME, vol. 119, pp. 462-466, September 1997.
[23] E. Howells, and E. T. Norton, "Parameters affecting the velocity of sound in transformer oil," IEEE T. Power Ap. Syst., vol. PAS-103, no. 5, pp. 1111-1115, 1984.
[24] K. S. Varde, "Bulk modulus of vegetable oil-diesel fuel blends," Fuel, vol. 63, pp. 713-715, 1984.
[25] B. O. Jacobson, and P. Vinet, "A model for the influence of pressure on the bulk modulus and the influence of temperature on the solidification pressure for liquid lubricants," J. Tribol. - T. ASME, vol. 109, pp. 709- 714, October 1987.
[26] M. Fukuhara, and T. Tsubouchi, "Naphthenic hydrocarbon oils transmissible for transverse waves," Chem. Phys. Lett., vol. 371, pp. 184-188, 2003.
[27] H. Kauranne, J. Kajaste, and M. Vilenius, Hydraulitekniikan perusteet. 3.-5. painos, Vantaa, Finland: Werner Söderström Osakeyhtiö, 2004. In Finnish.