scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Vibration Characteristics Analysis of Wide-Chord Hollow Fan Blade

01 Dec 2013-Applied Mechanics and Materials (Trans Tech Publications)-Vol. 482, pp 174-178
TL;DR: In this paper, the influence of the Rib Number and the Rib Thickness to Wide-Chord Hollow Fan Blade Vibration Characteristics has been analyzed and the results show that the wide-chord Hollow fan blades greatly improved the first-order VIBration Frequency compared with the Solid Blades.
Abstract: Wide-Chord Hollow Fan Blade is One of the New Technologies Used in Aircraft Engines. in this Paper, the Modal Analysis Method is Used to Analyze the Influence of the Rib Number and the Rib Thickness to Wide-Chord Hollow Fan Blade Vibration Characteristics. the Result Shows that the Wide-Chord Hollow Fan Blades Greatly Improves the First-Order Vibration Frequency Compared with the Solid Blades, and the First-Order Vibration Frequency of the Wide-Chord Hollow Fan Blades is Reduced with the Increasing Rib Number which is Not Good for Vibration Elimination. the Wide-Chord Hollow Fan Blades’ Vibration Frequency Changes a Little when the Rib Number is Larger than Three. in Addition, the Rib Thickness has Smaller Effect on Wide-Chord Hollow Fan Blade.
Citations
More filters
Journal ArticleDOI
TL;DR: In this paper, the vibration characteristics of a wide-chord fan blade were investigated using numerical and experimental methods, and the critical crossings in the Campbell diagram were indicated and evaluated, while the strain energy density index and weaklink were used to evaluate the dangerous locations for the high-cycle fatigue characteristics of the blade.
Abstract: The vibration characteristics of a wide-chord fan blade affect the safety, reliability, and operability of high-bypass ratio turbofan engines. In this study, the vibration characteristics of a fan blade were investigated using numerical and experimental methods. First, the natural frequencies and mode shapes were obtained and verified. Then, the rotating speed and frequency margins were employed to analyze the stability of the blade. The critical crossings in the Campbell diagram were indicated and evaluated. Next, the strain energy density index and weaklink were used to evaluate the dangerous locations for the high-cycle fatigue characteristics of the blade. Finally, single- and multi-axis random-excitation tests were performed. Results indicated that low-order bending modes were dominant under circumferential- and axial-direction excitations, while the torsional mode response was higher under radial-direction excitation. The weaklinks for different excitation directions exhibited different characteristics. This work presents a comprehensive understanding of the fan-blade vibration and response characteristics.

7 citations

01 Jan 2013
TL;DR: In this paper, the influence of the number and the wide of rib on the strength and stiffness of a hollow fan blade with rib was analyzed emphasizely and influence of production inaccuracy on the design result were analyzed.
Abstract: Aiming at the application of the design technique of wide chord fan blade on high bypass ratio aeroengine,taking a fan blade as example,the structure design method of hollow fan blade with rib was explored.The influence of the number and the wide of rib on the strength and stiffness of hollow blade were analyzed emphasizely and the influence of the production inaccuracy on the design result were analyzed.The result show that hollow fan blade with rib can be designed quickly by the design and analysis method of hollow fan.

1 citations

References
More filters
Journal ArticleDOI
TL;DR: In this article, a detailed wide-chord fan blade flutter analysis with emphasis on flutter bite was carried out using the same fan with three different intakes of increasing complexity to explain flutter mechanisms.
Abstract: This paper describes a detailed wide-chord fan blade flutter analysis with emphasis on flutter bite. The same fan was used with three different intakes of increasing complexity to explain flutter mechanisms. Two types of flutter, namely stall flutter and acoustic flutter, were identified. The first intake is a uniform cylinder for which there are no acoustic reflections. Only stall flutter, driven by flow separation, can exist in this case. The second intake, based on the first one, has a ‘bump’ feature to reflect the fan’s forward pressure wave at a known location so that detailed parametric studies can be undertaken. The analysis revealed a mechanism for acoustic flutter, which is driven by the phase of the reflected wave. The third intake has the typical geometric features of a flight intake. The results indicate that flutter bite occurs when both stall and acoustic flutter happen at the same speed. It is also found that blade stiffening has no effect on aero-acoustic flutter.Copyright © 2009 by Rolls-Royce plc

50 citations

Proceedings ArticleDOI
04 Jun 2001
TL;DR: Finite element modeling of bird impacts has been developed and calibrated using the 3-D impact analysis code MSC/DYTRAN, and the Arbitrary Lagrange Euler formulation is shown to be capable of capturing the physics of the bird impact problem, producing impact pressures and damage similar to that of a real bird.
Abstract: Finite element modeling of bird impacts has been developed and calibrated using the 3-D impact analysis code MSC/DYTRAN. These modeling efforts have shown that the Arbitrary Lagrange Euler (ALE) formulation within MSC/DYTRAN is capable of capturing the physics of the bird impact problem, producing impact pressures and damage similar to that of a real bird.This work is divided into two areas. First, a review of the literature was carried out to identify the physical processes, pressures and damage associated with real bird impacts. Second, finite element modeling of two simple bird impacts cases were carried out using MSC/DYTRAN. A comparison of the finite element predictions with the experimental data showed excellent agreement, and demonstrated the robustness of the ALE formulation.Copyright © 2001 by ASME

16 citations

Journal Article
TL;DR: In this article, a finite element model is established to study the vibration characteristics of fan blades, and natural frequencies and vibration modes are calculated when the shroud is free and constrained respectively.
Abstract: For high bypass ratio fans,the aeroengine always failures to work because the shrouded blades constantly suffer great centrifugal and vibration loadsTo study the vibration characteristics of fan blades,the finite element model is established,and natural frequencies and vibration modes are calculated when the shroud is free and constrained respectivelyIt is found that the natural frequencies are effected by the engine speed and shroud stationThe conclusions are of significance for further study on vibration characteristics of high bypass ratio fan blade

2 citations

01 Jan 2013
TL;DR: In this paper, the influence of the number and the wide of rib on the strength and stiffness of a hollow fan blade with rib was analyzed emphasizely and influence of production inaccuracy on the design result were analyzed.
Abstract: Aiming at the application of the design technique of wide chord fan blade on high bypass ratio aeroengine,taking a fan blade as example,the structure design method of hollow fan blade with rib was explored.The influence of the number and the wide of rib on the strength and stiffness of hollow blade were analyzed emphasizely and the influence of the production inaccuracy on the design result were analyzed.The result show that hollow fan blade with rib can be designed quickly by the design and analysis method of hollow fan.

1 citations