Raush, G.; Gamez-Montero, P.J.; Castilla, R.; Codina-Macia, Esteban Flow measurement and instrumentation Vol. 55, p. 13-22 DOI: 10.1016/j.flowmeasinst.2016.10.014 Data de publicació: 2017-06-01 Article en revista
All positive displacement pumps produce a pulsating flow. The present paper reports the experimental measurement of steady flow pulsations in the outlet of the internal wheeled pump. In the measured flow, the manufacturing tolerance are responsible of part of the spectra of the whole pulsation. Time-Resolved Particle Image Velocimetry technique has been used for this purpose. The flow pulsation measurement from a direct visualization of the velocity profile was carried out. The flow rate signal is derived from ad-hoc integration algorithm of the radial velocity profile, where the area discretization is a constant parameter that is relevant to minimize PIV errors by velocity gradients regions near the wall. Spectrographic analysis on the experimental data reveled low frequency components related with manufacturing tolerances. Measurements of this non-invasive procedure are compared with detailed CFD numerical results obtained from an improved gerotor model where manufacturing tolerances have been included. To be compared, cross-power spectral density analysis has been applied. The results reported in the paper show a method to provide a fast non-invasive flow pulsation measurement not only for pumps but also could be extended to compare aging effects of other kind of fluid power devices.
Ertürk, N.; Vernet , A.; Pallarès, J.; Castilla, R.; Raush, G. Flow measurement and instrumentation Vol. 29, p. 52-60 DOI: 10.1016/j.flowmeasinst.2012.09.004 Data de publicació: 2013-03 Article en revista
Recent technology advancements in Particle Image Velocimetry (PIV) technique offers a new possibility to study the complex turbulent flows over a wide range of scales. It can be used for the estimation of the turbulent kinetic energy dissipation rate including spatial derivatives of the velocity fluctuation components. In this study the flow characteristics of an external gear pump were studied with time-resolved Particle Image Velocimetry. Measurements were performed for two different spatial resolution configurations and various interrogation areas to estimate the dissipation rate of the turbulent kinetic energy. Results show that the spatial resolution is a critical factor in the accuracy of the measurements in the dissipation rate estimations. The optimal results can be achieved if the interrogation area is neither too large (sampling phenomenon) nor too small (noise in the measurement data). The effect of number of samples employed in the ensemble-averaging was considered as well.
Castilla, R.; Wojciechowski, J.; Gamez-Montero, P.J.; Vernet, A.; Codina-Macia, Esteban Flow measurement and instrumentation Vol. 19, num. 6, p. 377-384 DOI: 10.1016/j.flowmeasinst.2008.06.005 Data de publicació: 2008-12 Article en revista