Matrix equations for numerical calculation of natural combined modes and frequencies of vibration for a blade with concentrated weights are obtained. The results of the calculation of natural frequencies with concentrated weights located in the butt and at the end of the blade are presented.

Based on the statistical analysis of test results of production elastic multilayer beams, the variation range was determined, the expectation and variance of random values of the compliance of the hingeless hub of the helicopter main rotor, were obtained. The mechanical characteristics of the materials (fiberglass and rubber) that make up the elastic element were selected by the Nelder–Mead simplex method and the range of their spread at mass production was determined. The convergence of the applied method is shown.

Safety factors of the Ansat helicopter main rotor blade are determined in the root section at various flight modes with taking into account the possible damages.

The numerical method for calculating the induced velocities of the helicopter rotor was developed based on Shaidakov’s disk theory. The numerical experiments were performed to test and estimate the method developed.

This paper investigates the aerodynamic lift and drag of the ANSAT helicopter fuselage prototypes using Computational Fluid Dynamics. The CAD model of the fuselage was meshed using an unstructured grid and computed using a viscous flow model under the assumption of steady flow conditions. To account for the influence of the helicopter rotor an actuator disk model was used and the results were compared with computations for the isolated fuselage. The contributions to the total drag of the individual helicopter fuselage components were also studied using different turbulence models. The key components of the fuselage drag were identified.

Low fuselage drag has always been a key target of helicopter manufacturers. Therefore, this paper focuses on CFD predictions of the drag of several components of a typical helicopter fuselage. In the first section of the paper, validation of the obtained CFD predictions is carried out using wind tunnel measurements. The measurements were carried out at the Kazan National Research Technical University n.a. A. Tupolev. The second section of the paper is devoted to the analysis of drag contributions of several components of the ANSAT helicopter prototype fuselage using the RANS approach. For this purpose, several configurations of fuselages are considered with different levels of complexity including exhausts and skids. Depending on the complexity of the considered configuration and CFD mesh both the multi-block structured HMB solver and the unstructured commercial tool Fluent are used. Finally, the effect of an actuator disk on the predicted drag is addressed.

The basic equations of the main rotor blade motion with the preservation of nonlinear terms are presented. The results of analyzing the term values for nonlinear equations obtained for different flight regimes and several aeroelasticity problems are given.

A procedure of ANSYS software application for solving an inverse problem of composite elastic element strength of the helicopter main rotor is presented. The simplex method is used to select parameters in minimization of the objective residual functional. Both one-dimensional and three-dimensional variants of searching are considered. The elasticity characteristics of elastic hub materials as a function of temperature, obtained as a result of adjustment, are presented.

Small oscillations of isolated stiff blade in the rotation and flap planes about the steady-state motion of the rotor blade in horizontal flight and boundaries of instability of these oscillations, the so-called chord flutter, are considered. The method of determination of the main rotor chord flutter critical rate in forward flight is presented. Blade torsion is taken into account by means of a flapping compensator kinematic operation.