Effect of the aerodynamic force modeling on the tonal noise prediction model for axial fan: Sensitivity and uncertainty analysis

Abstract

The far-field acoustic pressure emitted by the unsteady rotating force acting by the fan on the fluid is computed using a tonal noise model prediction. Generally, the usefulness of any model depends in part on the accuracy and reliability of its output. Yet, because all models are imperfect abstractions of physical reality, and because precise input data are rarely if ever available, all output values are subject to imprecision. In this paper, the accuracy of the used tonal noise model prediction is easily influenced by the way in which the unsteady rotating force was modeled. To reach a good correlation between the numerical and experimental results, sensitivity and uncertainty analysis are conducted on the used model. The first one consists firstly on assigning to each model input the Sobol index. Then, according to the obtained index value, the most influential input is revealed. The second one leads to the assessment of uncertainties propagation through the model using the Monte Carlo simulation. Finally, the results from both analyses are presented and discussed.