REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

COMPUTATIONAL ANALYSIS OF HELICOPTER MAIN ROTOR BLADES IN GROUND EFFECT

ZORANA TRIVKOVIĆ

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, zposteljnik@mas.bg.ac.rs

JELENA SVORCAN

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, jsvorcan@mas.bg.ac.rs

MARIJA BALTIĆ

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, mbaltic@mas.bg.ac.rs

DRAGAN KOMAROV

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, dkomarov@mas.bg.ac.rs

VASKO FOTEV

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, vfotev@mas.bg.ac.rs

Abstract: Numerical investigation of an isolated representative helicopter main rotor has been performed in ANSYS FLUENT 16.2. In general, flow field around the rotor is unsteady, three-dimensional, complex and vortical. Such a simulation requires substantial computational resources. Ground effect, which improves the aerodynamic performances of the rotor, represents an additional challenge to numerical modeling. In this study, flow field is computed by Unsteady Reynolds Averaged Navier-Stokes (URANS) equations. Both Frame of reference and Sliding mesh approaches were employed to model the rotor rotation. Obtained results are compared to results obtained by simpler, sufficiently reliable models such as Momentum Theory (MT) and Blade Element Momentum Theory (BEMT). Presented results include fluid flow visualizations in the form of pressure, velocity and vorticity contours and the values of aerodynamic coefficients.

Keywords: helicopter, rotor, RANS, ground effect, power coefficient