CFD Calculation of Helicopter Tail Rotor Airloads for Fatigue Strength Experiments

Abstract

This work focuses on defining loads and fatigue life estimation of helicopter tail rotor blades. The original metal construction of these blades was replaced with a new construction of blades made from composite materials. The subject of this investigation is the precise determination of loads of helicopter composite tail rotor blades together with experimental verification of their fatigue strength. In this research to determine loads of tail rotor blades computational fluid dynamics (CFD) numerical simulations are used. To study the fatigue behavior of composite blades, the blades are here tested under static and fatigue load spectra. For determination of aerodynamic loads of tail rotor blades in this investigation, two computation models are used. In first model, an isolated tail rotor blade is considered. In the second computation model, the complete helicopter is modeled, including fuselage together with main and tail rotor blades. The tail rotor hub is not included in these computational models. To verify the strength of the composite structure of the tail rotor blade, it is tested under the static load and fatigue load spectra. The experimental fatigue test results under the load spectrum are included.