Parametrization of the main rotor and working environment for different flight conditions – Computational Fluid Dynamics analysis as an application for multidisciplinary optimization

Abstract

The paper shows a method of aerodynamic modelling of the whole rotor and exemplary results obtained from complex analyses. The analytical basis of rotor aerodynamics for different phases of the helicopter flight is shown. The analytical calculations are provided to model a single blade motion according to its azimuth angle and to validate the obtained results. The parametric design method is shown to be applied for different blade planform shapes and various section airfoils. The Computational Fluid Dynamics (CFD) fluid domain for the flow around the blade is also prepared using a parametric method. The parametric graphic script is developed to create the flow domain for a one-blade simulation or for a complete n-bladed rotor effect. The obtained blade model with enclosure is implemented into CFD environment. The method for fluid mesh preparation and the way of defining its properties are given. The simulation is carried out as transient for the n-bladed rotor. In this simulation, various flight conditions are taken into account. Real rotary motion of the blades is simulated with artificially enforced mesh motion. The obtained numerical results are compared then with analytical assumptions. The simulation findings which are the inputs for further analysis are shown with graphical representations. As an output of the research, new options for main rotor optimization are developed. The usage of combined parametric modelling confirmed with aerodynamic analysis for different flight conditions is shown in the work as a new perspective for design optimization of the main rotor.