Data Documentation for the Original Research Paper (ORP) entitled: "Global Measurements and hysteresis-based NPSH acoustic approach for the experimental study of cavitation in a centrifugal pump". General Information Experimental data associated with the aforementioned ORP authored by Álvaro Pardo Vigil, José González Pérez, Alberto García Suárez, Jesús M. Fernández Oro, Raúl Barrio Perotti and Mónica Galdo Vega, all members of the Fluid Mechanics Area in the Energy Department of the University of Oviedo. These datasets are protected under Creative Commons License: CC BY-NC-SA. Name of data set "Raw Data hysteresis based study of cavitation in a centrifugal pump" Name of data files in data set The files related to acoustic measurements have been named as QX_Y_Z_U, where: X is the Flow rate in m3/h Y is the beginning of the frequency period covered Z is the end of the frequency period covered U are the frequency units (Hz,Khz) The names for the rest of files are chosen so as to provide a sufficiently clear expalanation for the reader. Dataset language English Date the data set was last modified 14/01/2025 Funder At data treatment date, Álvaro Pardo Vigil was supported by the Spanish Ministry of Science, Innovation and Universities within the “FPU” Program (grant reference FPU23/03450). Methodology for data collection The data set are experimental data obtained from the experimental campaign carried out in the Fluid Mechanics Laboratory of the Polytechnic School of Engineering of Gijón (University of Oviedo). The acoustic measurements are obtained by means of a Brüel & Kjær 4189 microphone with 0.2 dB accuracy calibrated at 1 kHz and 94 dB by means of a Brüel & Kjær 4230 pistonphone, and data acquisition is performed by means of a SINUS SoundBook with embedded SAMURAI software. For head and flow rate measurements, the instrumentation available in the test rig is manually consulted, the data being read and noted for further postprocessing in separate Matlab files. Further information about on measurement uncertainty is available in the published text of the article "Global Measurements and hysteresis-based NPSH acoustic approach for the experimental study of cavitation in a centrifugal pump". Data collector Álvaro Pardo Vigil & Alberto García Suárez Date of data collection 14/01/2025 Person to contact with questions José González Pérez (aviados@uniovi.es) Data entry 18/03/2023 Software used to prepare data set Microsoft Excel 365, SAMURAI, Matlab, Windows Notepad Data processing that was performed PERFORMANCE DATA: Head and flow rate are non-dimensionalized using the head and flow coefficients, while the Net Positive Suction Head (NPSH) is also expressed in the non-dimensional form of the cavitation number (sigma). The value of sigma required for a certain head drop percentage (1%, 3%, 5%) is used to calculate the required cavitation umber, or sigma_r. ACOUSTIC DATA: Decibel measurements are converted to airborne acoustic pressure, which can be further adimensionalized as the cavitation noise level (CNL). Fast Fourier Transform is directly applied during data collection along a 7-second time period, and sound pressure colormaps are built for each flow rate relating the charactertistic frquencies and the covered range of cavitation numbers with their associated acoustic pressures. These sound pressure levels are RMS-averaged for certain frequency ranges of interest (the Blade Passage Freqyency BPF, the bubble frequencies above 5 kHz...) to show their evolution with the cavitation numbers. Finally, the whole range between 5 kHz and 10 kHz is averaged to obtain an evolution of high-pitched cavitation-borne noise that is easier to evaluate without requiring the study of discrete frequencies. Variables . Q: Pump flow rate [m3/h] . phi: Pump flow coefficient [-] . H: Pump head [m] . psi: Pump head coefficient [-] . p: Acoustic airborne pressure [mPa] . NPSH: Net Positive Suction Head [m] . sigma: Cavitation number [-] . f: Frequency [Hz] . CNL: Cavitation noise level [-] File Overview Inside the main folder "Raw Data hysteresis based study of cavitation in a centrifugal pump" ", two folders are available to separate the ACOUSTIC measurements and the pump PERFORMANCE results. In the PERFORMANCE folder, the following subdivision takes place: NONCAVITATING: The head/head coefficient and efficiency versus flow rate/flow coefficient curves at different impeller rotating speeds are provided, constituting the noncavitating characteristics of the pump under study. CAVITATING: The head drop curves, represented as H versus NPSH, are provided at the impeller rates of 20, 25, 30 and 35 Hz. Additionally, the adimensionalized sigma vs. phi curves are provided under different head drop criteria, as well as for cavitation inception conditions. In the ACOUSTIC folder, the following files are available: "FFT_Full_Dataset.xlsx" is a MS Excel spreadsheet where all the acoustic data are summarized without further processing aside from the decibel to mPa conversion. "FFT_baseline_comparison" shows a comparison between the baseline background noise level and the pump noise signature in noncavitating conditions. "QX_Y_Z_U" files show colormaps and curves summarizing the previous results either in discrete frequencies or frequency ranges which are physically significant, such as the Blade Passing Frequency (BPF).