scholarly journals Design of flexible support for fast steering mirror via kinematic principles

2021 ◽  
Vol 42 (3) ◽  
pp. 1-5
Author(s):  
WANG Dazhi ◽  
◽  
◽  
FAN Yue ◽  
◽  
...  
Keyword(s):  
Flexible Support

Analysis of the inherent characteristics of rotor-diaphragm coupling – flexible support system

2017 ◽  
Vol 3 (1) ◽  
pp. 9-16
Author(s):  
Yu Guangbin ◽  
◽  
Duan Yuanwang ◽  
Zhao Xinhui ◽  
Tian Ren ◽  
...  
Keyword(s):  
Support System ◽  
Flexible Support

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

Parametrically Excited Electrostatic MEMS Cantilever Beam With Flexible Support

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mark Pallay ◽  
Shahrzad Towfighian
Keyword(s):  
Cantilever Beam ◽  
Large Amplitude ◽  
Chaotic Behavior ◽  
Signal To Noise Ratio ◽  
Mass Sensors ◽  
Flexible Support ◽  
Sensing Applications ◽  
Electrostatic Mems ◽  
Fringe Fields ◽  
Steady State Amplitude

Parametric resonators that show large amplitude of vibration are highly desired for sensing applications. In this paper, a microelectromechanical system (MEMS) parametric resonator with a flexible support that uses electrostatic fringe fields to achieve resonance is introduced. The resonator shows a 50% increase in amplitude and a 50% decrease in threshold voltage compared with a fixed support cantilever model. The use of electrostatic fringe fields eliminates the risk of pull-in and allows for high amplitudes of vibration. We studied the effect of decreasing boundary stiffness on steady-state amplitude and found that below a threshold chaotic behavior can occur, which was verified by the information dimension of 0.59 and Poincaré maps. Hence, to achieve a large amplitude parametric resonator, the boundary stiffness should be decreased but should not go below a threshold when the chaotic response will appear. The resonator described in this paper uses a crab-leg spring attached to a cantilever beam to allow for both translation and rotation at the support. The presented study is useful in the design of mass sensors using parametric resonance (PR) to achieve large amplitude and signal-to-noise ratio.

Active Segmented Trim Panels for Aircraft Interior Noise Control: Theory and Experiments

1999 ◽  
Author(s):  
S. M. Hirsch ◽  
J. Q. Sun
Keyword(s):  
Noise Control ◽  
Secondary Source ◽  
Acoustic Source ◽  
Simple Modification ◽  
Secondary Sources ◽  
Flexible Support ◽  
Low Profile ◽  
Modification Of Materials ◽  
Trim Panel ◽  
Theory And Experiments

Abstract An active segmented trim panel for use as a secondary source for noise control in aircraft is designed, analyzed and tested. It consists of a rectangular segment of aircraft trim panel which is suspended by a flexible support. This support converts the stiff composite trim panel into flexibly-mounted pistons which can be driven by light-weight and low-profile force actuators. The active segmented trim panel offers an acoustic source of lower profile and lower mass, and requires only a simple modification of materials already installed on aircraft. This paper presents a summary of recent results of modeling and testing of an active trim panel configuration. Real-time noise control experiments are conducted using the active trim panels as secondary sources indicating that the present active segmented trim is a promising technology.

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