Gear pump noise digital twin with modal expansion of vibration measurements

The association of experimental measurements with numerical simulation often brings a philosophical question whether one might improve the other. It is nowadays well admitted that the digital twin allows for an optimization of processes in general. Furthermore, including experimental data into the numerical world also helps with bringing more realistic simulated results. In this paper, a hybrid numerical-experimental integrated approach is presented to obtain accurate predictions of the noise field emitted by an 8.5 cc/rev external gear pump starting from vibration measurements. These are obtained as acceleration spectra in a few specific positions of the external gear pump casing for some working conditions. A numerical structural modal expansion of these measurements on a reduced set of point is used to expand the knowledge of the vibrations onto a full structural mesh. The obtained structural dynamic response is then integrated in a finite element vibro-acoustic model to simulate the noise field radiated by the gear pump. The commercial software Simcenter 3D was used to execute this modal expansion, as well as the acoustic analysis, by means of several numerical methods such as the classical FEM (Finite Element Method), the more elaborated FEMAO (Finite Element Method with Adaptive Order), and the ATV (Acoustic Transfer Vector) approach. The validation of the hybrid method combining the modal expansion of measurements with vibro-acoustic simulation was carried out with sound power calculations based on sound intensity measurements and with sound pressure measurements around the pump casing. A good accuracy is obtained with the proposed hybrid approach, offering a pertinent alternative to sometimes potentially heavy numerical modelling requirements.