Development and validation of a CFD model of a ducted fan for a low speed aircraft

The paper describes the development and validation of a CFD model of a ducted fan intended for use in a small-sized tiltrotor eVTOL. The ducted fan includes the duct with an airfoil section, the fan with 10 blades and 9 guide vanes. The computational study was carried out using the commercial software Numeca Fine/Turbo. The impact of modeling approaches (URANS, RANS with different types of rotor-stator interface) and turbulence models (Spalart — Allmaras, k–? SST Menter, SSC-EARSM) was analyzed at the angle of attack ? = 45°, rotational speed n = 0.85 and advance ratio J = 0.48. It was shown that fine meshes, unsteady approaches and advanced turbulence models should be used to improve the accuracy of computational predictions at high angles of attack. The numerical thrust agrees well with the bench tests data in a range of the fan rotational speeds. The numerical data was compared with aerodynamic coefficients CX, CY obtained in the wind tunnel tests at the fan rotational speeds n = 0.85, 0.64, 0.43 in a range of advance ratio J = 0.09...0.72 and angles of attack ? = 0…90°. An acceptable agreement between the numerical and wind tunnel data is observed at all modes. The error augmentation is noticed at the modes with the low Reynolds numbers.
EDN: AIMRAH, https://elibrary/aimrah

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