Performance optimization of helicopter rotor blade

Modern helicopters are complex dynamic systems that are subject to high levels of vibration and fatigue during their lifetime, due to their tasks and working environments. Vibration is one of the most important factors to consider in helicopter rotor design and performance studies. In addition to the damage caused to the mechanical system components of vibration, there are also negative consequences such as human discomfort and disease, difficulty in reading, ineffectiveness of weapon systems and high maintenance costs. In this study, it is aimed to increase helicopter performance by reducing helicopter rotor blade vibration. In helicopter rotor design, active and passive control methods are widely discussed to minimize vibration. In active control methods; it comes with instant feedback to the system through sensors, propulsion systems and controllers, and the system includes significant complexity. In contrast, passive control methods use less complex components like, vibration absorbers which respond to the load and to the direction of where it comes, isolators, and structural distribution of materials. At the same time, by through passive control methods, it is possible to examine the vibration at the rotor head with "surrogate vibration reduction formula". This equality expresses the vibration at the rotor head in terms of shear forces and moments. The surrogate vibration formula was used as the objective function of the performance optimization model. Constraints are cross-sectional geometry limitations and structural properties of the material such as frequency placement, autorotation and stress. Composite layer angles and spar geometry are design variables. A hybrid algorithm solution was preferred as an optimization method. Because the gradient-based algorithms produce precise results in the safe zone and the heuristic methods can scan the search space wide, the particle swarm algorithm and the gradient-based algorithm have been hybridized. The VABS software was used for cross-sectional analysis in the performance improvement to be performed for the helicopter in the flight forward condition.Cross-section geometry's mesh information is produced with ABAQUS using PYTHON script. By the DYMORE program, which is used in the dynamic analysis of air vehicles, calculated the applied forces and moments per rotor. In order to perform sequential transactions between VABS, ABAQUS and DYMORE in each iteration, Microsoft's next-generation programming language, C #, has been utilized. Optimization was done in MATLAB numerical analysis and calculation program. The optimized results were compared with the reference UH-60 helicopter rotor head vibration and with the new design, observed a vibration reduction of about 38 percent at the rotor hub.