Vibrations of an elastic disc bearing a blade assembly in compound rotation

1996 ◽  
Vol 28 (6) ◽  
pp. 462-469
Author(s):  
V. I. Gulyaev ◽  
R. V. Domaretskii
Keyword(s):  
Compound Rotation ◽  
Blade Assembly ◽  
Elastic Disc

scholarly journals A Low-Cost MEMS Missile-Borne Compound Rotation Modulation Scheme

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4910
Author(s):  
Xiaoqiao Yuan ◽  
Jie Li ◽  
Xi Zhang ◽  
Kaiqiang Feng ◽  
Xiaokai Wei ◽  
...  
Keyword(s):  
Rotation Axis ◽  
Low Cost ◽  
Roll Angle ◽  
Modulation Scheme ◽  
Navigation Systems ◽  
Rotation Scheme ◽  
Compound Rotation ◽  
Error Accumulation ◽  
Axis Rotation ◽  
Single Axis Rotation

Rotation modulation (RM) has been widely used in navigation systems to significantly improve the navigation accuracy of inertial navigation systems (INSs). However, the traditional single-axis rotation modulation cannot achieve the modulation of all the constant errors in the three directions; thus, it is not suitable for application in highly dynamic environments due to requirements for high precision in missiles. Aiming at the problems of error accumulation and divergence in the direction of rotation axis existing in the traditional single-axis rotation modulation, a novel rotation scheme is proposed. Firstly, the error propagation principle of the new rotation modulation scheme is analyzed. Secondly, the condition of realizing the error modulation with constant error is discussed. Finally, the original rotation modulation navigation algorithm is optimized for the new rotation modulation scheme. The experiment and simulation results show that the new rotation scheme can effectively modulate the error divergence of roll angle and improve the accuracy of roll angle by two orders of magnitude.

3-D elastic coupling vibration and acoustical radiation characteristics of cracked gear under elastic support condition

2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Three Dimensional ◽  
Elastic Support ◽  
Dynamic Responses ◽  
Tooth Root ◽  
Support Condition ◽  
Elastic Boundary ◽  
Root Crack ◽  
Elastic Disc

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.

scholarly journals The Influence of a Mistuned Blade’s Staggle Angle on the Vibration and Stability of a Shaft-Disk-Blade Assembly

2008 ◽  
Vol 15 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Yi-Jui Chiu ◽  
Shyh-Chin Huang
Keyword(s):  
Natural Frequencies ◽  
Linear Trend ◽  
Rotor System ◽  
Instability Point ◽  
Blade System ◽  
Blade Assembly ◽  
The Stability

The influence on coupling vibrations and stability among shaft-torsion, disk-transverse and blade-bending of a rotor system with a mistuned blade's staggle angle was investigated analytically. A shaft-disk-blade system has been found existing two types of coupling vibrations, disk-blade (DB), and blade-blade (BB) modes when the shaft was assumed rigid. If the shaft's torsional flexibility was taken into account, an additional type of coupling modes, shaft-disk-blade (SDB), appeared. When an angle-mistuned blade existed, the blades periodicity was destroyed and it was found to change not only the natural frequencies but also the types of modes. Due to blade's mistune, the shaft torsion had to participate to balance such that DB modes vanished and replaced by SDB modes. A mistuned staggle angle was numerically found to alter the natural frequencies in an almost linear trend. At last, the rotational effects were found to merge frequency loci and eventually reached an instability point. Very interestingly, a mistuned blade diminished the possible instability caused by blade-dominating modes, which existed in a perfect and periodic rotor. In words, the rotor might benefit from a mistuned blade from the stability viewpoint. The shaft-dominating mode, yet, was unaffected by the mistune and retained a possible instability.

Performance Simulations of a Gas Turbine Disk-Blade Assembly Employing Miniature Radially Rotating Heat Pipes

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Yiding Cao ◽  
Jian Ling
Keyword(s):  
Heat Pipe ◽  
Numerical Investigation ◽  
Gas Turbines ◽  
Heat Pipes ◽  
Turbine Disk ◽  
Maximum Temperature ◽  
Material Strength ◽  
Inlet Temperature ◽  
Pipe Length ◽  
Blade Assembly

With a substantially increased gas inlet temperature in modern gas turbines, the cooling of turbine disks is becoming a challenging task. In order to reduce the temperature at the disk rim, a new turbine disk incorporating radially rotating heat pipes has been proposed. The objective of this paper is to conduct a numerical investigation for the cooling effectiveness of the rotating heat pipe. One of the major tasks of this paper is to compare the performance between a proposed disk-blade assembly incorporating radially rotating heat pipes and a conventional disk-blade assembly without the heat pipes under the same heating and cooling conditions. The numerical investigation illustrates that the turbine disk cooling technique incorporating radially rotating heat pipes is feasible. The maximum temperature at the rim of the proposed disk can be reduced by more than 100 °C in comparison with that of a conventional disk without heat pipes. However, the average temperature at the blade airfoil surface can be reduced by only about 10 °C. In addition, both the heat pipe length and diameter have an important effect on the turbine disk cooling. Under the permission of material strength, a longer heat pipe or a larger heat pipe diameter will produce a lower temperature at the disk rim.

Sign in / Sign up

Export Citation Format

Share Document