Damper Optimization Design of High-Speed Energy Storage Flywheel Shafting with a Single Point Flexible Support

2014 ◽  
Vol 672-674 ◽  
pp. 509-517
Author(s):  
Chang Liang Tang ◽  
Dong Jiang Han ◽  
Jin Fu Yang ◽  
Xing Jian Dai

The flywheel energy storage technology is a new type of conversion and storage for electric energy, and it is also a research hotspot of energy field in the world. There are a large number of studies on dynamic characteristics of energy storage flywheel in recent years. The flexible support with a single point has small load-carrying ability but very low friction loss, which is appropriate to be used in small flywheel system. By using a small stiffness pivot-jewel bearing and an oil damper as the lower support of the flywheel, a high-speed flywheel shafting with a single point flexible support was built. The dynamic model of the shafting was obtained by means of the Lagrangian equation. Based on the same energy dissipation of oil damper and flywheel, the optimal equivalent damping of flywheel was determined. The optimization criteria for dynamic state and parameters between oil damper and shafting were also presented. The lower damper’s effects on the mode shapes, modal damping ratios and forced vibration were discussed.

2011 ◽  
Vol 471-472 ◽  
pp. 37-42 ◽  
Author(s):  
Renuganth Varatharajoo ◽  
Faizal Mustapha ◽  
Dayang Laila Abang Abdul Majid ◽  
Rizal Zahari ◽  
Ralph Kahle

A numerical investigation to optimize the carbon/epoxy multi layer composite rotor is performed for the spacecraft energy storage application. A high-speed double and triple layer rotor design is proposed and different composite materials are tested to achieve the most suitable recipe. First, analytical rotor evaluation was performed in order to establish a reliable numerical composite rotor model. Subsequently, finite element analysis is employed in order to optimize the double and triple layer composite rotors. Then, the modal analysis was carried out to determine the rotor natural frequencies. The rotor stress distributions and the rotor mode shapes show that a safe operational regime below 46, 000 rotations per minute is achievable.


2013 ◽  
Vol 561 ◽  
pp. 496-500
Author(s):  
De Gong Chang ◽  
Hong Yun Dou ◽  
Fu Qin Yang ◽  
Rong Zong

According to the working principle and structural characteristics of cylinder mechanism, the simplified model is built by the Pro/E software. Then we carry on the modal analysis for cylinder mechanism combined with ANSYS Workbench [1], and obtain the natural frequency and mode shapes of all steps. It provides the basis for optimization design and safety evaluation of cylinder mechanism. Finally, we study the influence of bearing stiffness on the critical speed, which provides the basis for the research of high-speed cylinder.


2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.


Author(s):  
Zijian Guo ◽  
Tanghong Liu ◽  
Wenhui Li ◽  
Yutao Xia

The present work focuses on the aerodynamic problems resulting from a high-speed train (HST) passing through a tunnel. Numerical simulations were employed to obtain the numerical results, and they were verified by a moving-model test. Two responses, [Formula: see text] (coefficient of the peak-to-peak pressure of a single fluctuation) and[Formula: see text] (pressure value of micro-pressure wave), were studied with regard to the three building parameters of the portal-hat buffer structure of the tunnel entrance and exit. The MOPSO (multi-objective particle swarm optimization) method was employed to solve the optimization problem in order to find the minimum [Formula: see text] and[Formula: see text]. Results showed that the effects of the three design parameters on [Formula: see text] were not monotonous, and the influences of[Formula: see text] (the oblique angle of the portal) and [Formula: see text] (the height of the hat structure) were more significant than that of[Formula: see text] (the angle between the vertical line of the portal and the hat). Monotonically decreasing responses were found in [Formula: see text] for [Formula: see text] and[Formula: see text]. The Pareto front of [Formula: see text] and[Formula: see text]was obtained. The ideal single-objective optimums for each response located at the ends of the Pareto front had values of 1.0560 for [Formula: see text] and 101.8 Pa for[Formula: see text].


Sign in / Sign up

Export Citation Format

Share Document