Helicopter Engine - Rotor System Compatibility

1962 ◽  
Author(s):  
Keyword(s):  
Rotor System ◽  
Engine Rotor

Multi Objective Optimisation of an Aero Engine Rotor System Using Nondominated Sorting Genetic Algorithm (NSGA)

2017 ◽  
Author(s):  
Joseph Shibu Kalloor ◽  
Ch. Kanna Babu ◽  
Girish K. Degaonkar ◽  
K. Shankar
Keyword(s):  
Genetic Algorithm ◽  
Critical Speed ◽  
Rotor System ◽  
Pareto Optimal ◽  
Multi Objective ◽  
Rayleigh Beam ◽  
Unbalance Response ◽  
Aero Engine ◽  
Nondominated Sorting ◽  
Engine Rotor

A comprehensive multi-objective optimisation methodology is presented and applied to a practical aero engine rotor system. A variant of Nondominated Sorting Genetic Algorithm (NSGA) is employed to simultaneously minimise the weight and unbalance response of the rotor system with restriction imposed on critical speed. Rayleigh beam is used in Finite Element Method (FEM) implemented in-house developed MATLAB code for analysis. The results of practical interest are achieved through bearing-pedestal model and eigenvalue based Rayleigh damping model. Pareto optimal solutions generated and best solution selected with the help of response surface approximation of the Pareto optimal front. The outcome of the paper is a minimum weight and minimum unbalance response rotor system which satisfied the critical speed constraints.

scholarly journals Spectrum Analysis of a Coaxial Dual-Rotor System with Coupling Misalignment

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Hongxian Zhang ◽  
Liangpei Huang ◽  
Xuejun Li ◽  
Lingli Jiang ◽  
Dalian Yang ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Element Model ◽  
Rotor System ◽  
Harmonic Frequencies ◽  
Coaxial Rotor ◽  
Outer Rotor ◽  
Frequency Components ◽  
Harmonic Resonance ◽  
The Finite Element Model ◽  
Engine Rotor

The finite element model of a dual-rotor system was established by Timoshenko beam element. The dual-rotor system is a coaxial rotor whose supporting structure is similar to that of an aero-engine rotor system. The inner rotor is supported by three bearings, which makes it a redundantly supported rotor. The outer rotor connects the inner rotor by an intershaft bearing. The spectrum characteristics of the dual-rotor system under unbalanced excitation and misalignment excitation were analysed in order to study the influence of coupling misalignment of the inner rotor on the spectral characteristics of the rotor system. The results indicate that the vibration caused by the misaligned coupling of the inner rotor will be transmitted to the outer rotor through the intershaft bearing. Multiple harmonic frequency components, mainly 1x and 2x, will be excited by the coupling misalignment. The amplitudes of all harmonic frequencies increase with the misalignment in both the inner and outer rotors. The vibration level of the outer rotor affected by the misalignment is lower than that of the inner rotor because it is far from the misaligned coupling. Harmonic resonance occurs when any harmonic frequencies of the misalignment response coincide with a natural frequency of the system. In order to verify the theoretical model, experiments are performed on a test rig. Both the experimental and simulation results are in good accordance with each other.

Modelling of Misaligned Rotor System in Aero-Engines and Interval Method Investigation

2013 ◽  
Author(s):  
Guihua Wang ◽  
Yanhong Ma ◽  
Tianrang Li ◽  
Jun Li ◽  
Jie Hong
Keyword(s):  
Dynamic Response ◽  
Rotor System ◽  
Mechanical Parameters ◽  
Lagrange Method ◽  
Interval Method ◽  
Aero Engine ◽  
Mechanical Factors ◽  
Aero Engines ◽  
Rotor Model ◽  
Engine Rotor

Based on the structural and dynamic characteristics of aero-engine rotor system, we used Lagrange method to develop a two-bearing and a multi-bearing rotor model with misalignment. An equation of motion was derived with features of response examined. Due to the uncertainty of mechanical parameters, interval method was adopted to investigate the dynamic response of rotor system with misalignment. Dynamic response and influence of the key mechanical parameters will be obtained in further research. The two times harmonic was found as a distinctive feature of misalignment and the magnitude of it in spectrum is closely related to some key mechanical factors. We also found interval method outstandingly performed in investigating dynamic response when some key parameters are uncertain.

Bending Stiffness and Dynamic Characteristics of a Rotor With Spline Joints

2013 ◽  
Author(s):  
Fayong Wu ◽  
Zhichao Liang ◽  
Yanhong Ma ◽  
Dayi Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Bending Stiffness ◽  
Rotor System ◽  
Contact State ◽  
Structural Discontinuity ◽  
Aero Engine ◽  
Stiffness Characteristics ◽  
Stiffness Distribution ◽  
Engine Rotor

Spline is a kind of typical joint structures widely used in the aero-engine rotor system. The stiffness distribution of the spool is affected by the spline joint’s stiffness directly. Therefore, it is significant to investigate the spline joint’s stiffness characteristics and its influences on the dynamic characteristics of the rotor system. To figure out the factors that affect the bending stiffness of the spline joint, a mechanical model which takes contact state into account was built based on the structure analysis and force state analysis. In addition, an actual rotor with a spline joint was established to measure the stiffness under different loads, and the results were compared with the analysis by three modeling methods. Furthermore, the natural frequencies of the rotor were tested. Obtained results indicate that the structural discontinuity, the surface stiffness and the clearance fit cause the loss of local angular stiffness and linear stiffness. Meanwhile, the stiffness of the rotor with the spline joint is weaker along with the increase of the load/deformation, and become stable when undergoing the huge load/deformation. Besides, the local blending stiffness is presented as nonlinear and uncertainty subjected to an interval, which further affected the dynamic characteristics of rotor system.

Sign in / Sign up

Export Citation Format

Share Document