Integration of parameter sensitivity to structural optimization of helicopter rotors for minimum vibration

2020-10-01
Bilen, Muhammed Emre
Ciğeroğlu, Ender
Özgüven, Hasan Nevzat
Helicopters are notorious for their high vibration levels and the rotor systems are the main contributors to the problem. Rotor vibrations can be minimized by optimizing the rotor structure. However, the result of the optimization might require precise manufacturing of the rotor with tight tolerances leading to increased production cost and time. Moreover, due to loose manufacturing tolerances or wear from usage, the rotor might present higher vibrations during operation if the rotor vibration is sensitive to slight variations in the design variables. Hence, it is important to obtain a design point for minimum vibration that is also insensitive to such deviations. In this study, a four-bladed helicopter rotor is structurally optimized for minimum vibration and minimum blade mass. Along with these objectives, the sensitivity of each design point to variable deviations is calculated and combined into the objective function. It is aimed to obtain a design point resulting in minimum vibration and blade mass with the least variable sensitivity. Surrogate-based models are incorporated for the optimization to reduce objective function and sensitivity calculation times. For vibration minimization, vibration amplitudes along the rotor blades and at the rotor hub are considered. Furthermore, blade natural frequencies are separated from excitation frequencies to avoid any potential resonance. A comparative study is presented to provide the effect of parameter sensitivity.

Suggestions

Integration of Parameter Sensitivity to Structural Optimization of Helicopter Rotors for Minimum Vibration
Bilen, Muhammed Emre; Ciğeroğlu, Ender; Özgüven, Hasan Nevzat (CRC, New York , 2020-10-01)
Helicopters are notorious for their high vibration levels and the rotor systems are the main contributors to the problem. Rotor vibrations can be minimized by optimizing the rotor structure. However, the result of the optimization might require precise manufacturing of the rotor with tight tolerances leading to increased production cost and time. Moreover, due to loose manufacturing tolerances or wear from usage, the rotor might present higher vibrations during operation if the rotor vibration is sensitive ...
Development of a hybrid global optimization algorithm and its application to helicopter rotor structural optimization
Bilen, Muhammed Emre; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2019)
Helicopters are notorious for their high vibration levels and the rotor system are the main contributors to the problem. The rotor vibrations can be minimized by optimizing the rotor structure, which require time-consuming high-fidelity solution for vibration predictions. To solve this problem, an effective and efficient global search algorithm called Explorer-Settler Optimization algorithm is developed by combining the advantageous aspects of Particle Swarm Optimization and Nelder-Mead Optimization algorit...
Evaluation of Surrogate-Based Modeling Methods for the Optimization of Helicopter Rotor Structures for Minimum Vibration
Bilen, Muhammed Emre; Ciğeroğlu, Ender; Özgüven, Hasan Nevzat (null; 2019-11-02)
Helicopters are notorious for their high vibration levels and the rotors are the main contributors. At preliminary stages, it is essential to design the rotors to achieve minimum vibration amplitudes, which is generally realized by using optimization routines. The optimization of a helicopter rotor for minimum vibrations requires repeated high-fidelity solutions, which lead to high computational times. Moreover, since the rotor optimization problem contains many local minima by its nature, the optimization ...
Estimation of Critical Submergence at Single Horizontal Intakes Under Asymmetric Flow Conditions
Haspolat, Emre (2022-01-01)
Air-entraining vortices are one of the serious hydraulic phenomena which can create various problems during the operation of intakes. Generally, air-entraining vortices start to form when the intake submergence is insufficient and less than a critical value. The purpose of the present study is to investigate the formation of air-entraining vortices and determine the critical submergences at single horizontal intake under asymmetrical approach flow conditions by conducting experiments with four different pip...
Simulation Based Optimal Sensor Actuator Positioning on a Fin Like Structure
Pedremasl, Nıma; Şahin, Melin; Acar, Erdem (2015-06-26)
Aircraft structures are subjected to high amplitude dynamic loads under service conditions; hence, it is necessary to determine their dynamic properties. Dynamic properties of a structure can be determined using simulation-based methods (e.g., finite element method) or using experimental modal analysis (EMA) methods. An EMA system should be lightweight and accurate so that it does not have a negative impact on the dynamic performance of the structure. For this purpose, the transducers (sensor and actuators)...
Citation Formats
M. E. Bilen, E. Ciğeroğlu, and H. N. Özgüven, Integration of parameter sensitivity to structural optimization of helicopter rotors for minimum vibration. 2020.