The article presents results of simulations concerning possibilities of rotorcraft performance enhancements for compound helicopters with introduced additional wings and propellers. The simple model of helicopter including a point mass of fuselage and a rotor treated as a disk was used for calculations of helicopter flight equilibrium conditions. For the defined flight states, the more detailed model of elastic blade was applied to compute magnitude of rotor loads and level of blade deformations. The model of elastic blade includes out-of-plane bending, in plane bending, and torsion effects due to variable aerodynamic and inertial loads of rotor blades. Equations of motion of rotor blades are solved applying Runge-Kutta method. Taking into account Galerkin method, parameters of blade motion are computed as a combination of assumed torsion and bending Eigen modes of the rotor blade. The six-bladed rotor with stiff connections of blades and hub was applied for comparison of flight envelope for conventional helicopter and versions of compound rotorcraft with additional propellers and with wings and propellers. Simulations indicate that, in the case of compound helicopter configuration, achieving the operational flight conditions at high speed of 400 km/h is possible without generating excessive loads and blade deformations. The results of calculations of rotor loads and generated blade deflections are presented in form of time-run plots and as rotor disk distributions, which depend on radial and azimuthal positions of blade elements. The simulation investigation may help to define demands for rotor of high-speed helicopter.
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 Datta, A., Yeo, H., Norman, T. R., Experimental investigation and fundamental understanding of a slowed UH-60A rotor at high advance ratios, American Helicopter Society 66th Annual Forum, Virginia Beach, Virginia, May 3-5, 2011.
 Ferguson, K. M., Thomson, D. G., Flight dynamics investigation of compound helicopter configurations, AHS 69th Annual Forum, Phonix, Arizona, May 22-23, 2013.
 Hirschberg, M., X2, X3, S-97, and X-49: The battle of the compounds is joined, Vertiflite, Vol. 56, No. 4, pp. 16-22, 2010.
 Hirschberg M., Dynamic developments continue apace: New Sikorsky and Bell rotorcraft forge ahead, Vertiflite, Vol. 61, No. 6, pp. 16-19, 2015.
 Robb, R. L., Hybrid helicopters: compounding the quest for speed, Vertiflite, Vol. 52, No. 6, pp. 30-56, 2006.
 Silva, C., Yeo, H., Johnson, W., Design of a slowed-rotor compound helicopter for future joint service missions, American Helicopter Society Aeromechanics Specialist’s Conference, San Francisco, January 20-22, 2010.
 Yeo, H., Johnson, W., Optimum Design of a Compound Helicopter, American Helicopter Society International Meeting on Advanced Rotorcraft Technology and Lift Saving Activity, Nagoya, Japan, November 15-17, 2006.