Some Features of Rotor Dynamics inside Floating Sealing Ring

2006 ◽  
Vol 113 ◽  
pp. 247-251
Author(s):  
L.Y. Banakh ◽  
A.N. Nikiforov ◽  
G.Y. Panovko
Keyword(s):  
High Speed ◽  
Rotor Dynamics ◽  
Rotor Vibration ◽  
Coupled Vibrations ◽  
Dynamic Forces ◽  
Sealing Ring ◽  
Turbo Pump

Flow-coupled vibrations of system “rotor-ring” are researched. Absence effect of critical rotor velocity and dynamic absorption of rotor vibration in the system “rotor-ring” is described. These properties are caused by aero(hydro)dynamic forces in the clearance between rotor and ring. Result of lowered vibration for high-speed rotor of turbo-pump containing floating sealing rings is submitted.

Flow-Coupled Vibrations of Rotor and Seal

2005 ◽  
Vol 11 (7) ◽  
pp. 887-901 ◽  
Author(s):  
R. Akhmetkhanov ◽  
L. Banakh ◽  
A. Nikiforov
Keyword(s):  
Analytical Solutions ◽  
Coulomb Friction ◽  
High Speed ◽  
Stationary Case ◽  
Coupled Vibrations ◽  
Unbalanced Rotor ◽  
Sealing Ring ◽  
Synchronous Oscillations ◽  
Operating Regimes ◽  
Coulomb Friction Force

We study the flow-coupled vibrations of an unbalanced rotor and a floating sealing ring. The rotor is high speed; its operating regimes are above second critical velocity. The ring is subjected to Coulomb friction force, which prevents its motion about the casing. At rotor rotation, the intensive vibrations of rotor and floating ring take place and the hydrodynamic forces in clearance between them are dominated. Non-impact and impact regimes are revealed and the latter are very dangerous for safety. In the stationary case, the analytical solutions for impact regimes are obtained; these show that synchronous oscillations of rotor and floating ring may occur. The non-stationary oscillations during startup and shutdown are also considered. Domains for the trouble-free non-impact regimes by various rotor velocities are determined. Rotor trajectories with impacts are submitted.

Rotor-Dynamics of Different Shaft Configurations for a 6 kW Micro Gas Turbine for Concentrated Solar Power

2016 ◽  
Author(s):  
A. Arroyo ◽  
M. McLorn ◽  
M. Fabian ◽  
M. White ◽  
A. I. Sayma
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Dynamic Models ◽  
Solar Power ◽  
Critical Issue ◽  
Rotor Dynamics ◽  
Mode Shapes ◽  
Concentrated Solar Power ◽  
Element Analysis ◽  
Rotor Dynamic

Rotor-dynamics of Micro Gas Turbines (MGTs) under 30 kW have been a critical issue for the successful development of reliable engines during the last decades. Especially, no consensus has been reached on a reliable MGT arrangement under 10 kW with rotational speeds above 100,000 rpm, making the understanding of the rotor-dynamics of these high speed systems an important research area. This paper presents a linear rotor-dynamic analysis and comparison of three mechanical arrangements of a 6 kW MGT intended for utilising Concentrated Solar Power (CSP) using a parabolic dish concentrator. This application differs from the usual fuel burning MGT in that it is required to operate at a wider operating speed range. The objective is to find an arrangement that allows reliable mechanical operation through better understanding of the rotor dynamics for a number of alternative shaft-bearings arrangements. Finite Element Analysis (FEA) was used to produce Campbell diagrams and to determine the critical speeds and mode shapes. Experimental hammer tests using a new approach based on optical sensing technology were used to validate the rotor-dynamic models. The FEA simulation results for the natural frequencies of a shaft arrangement were within 5% of the measurements, while the deviation for the shaft-bearings arrangement increased up to 16%.

An Experimental and Analytical Study of Connection Forces in High-Speed Mechanisms

1975 ◽  
Vol 97 (4) ◽  
pp. 1166-1174 ◽  
Author(s):  
S. Dubowsky ◽  
S. C. Young
Keyword(s):  
High Speed ◽  
Analytical Study ◽  
Dominant Role ◽  
Mechanical Systems ◽  
Design Engineers ◽  
Experimental Behavior ◽  
Dynamic Forces

The increases in the dynamic forces within the connections of high-speed mechanical systems due to connection clearances and mechanism elasticity are of great interest to design engineers. These forces, which can play a dominant role in the performance and life of these systems, are experimentally studied in this investigation, and the observed experimental behavior is correlated with the results of analytical predictions. The experiments performed confirm the importance of clearances in machine joints on the amplification of connection forces. The effects of connection friction and mechanism elasticity on the connection forces are also investigated.

Estimation of Dynamic Forces in Very High-Speed Impact Forging

1966 ◽  
Vol 88 (4) ◽  
pp. 369-372 ◽  
Author(s):  
M. J. Hillier
Keyword(s):  
Approximate Solution ◽  
Velocity Field ◽  
Plane Strain ◽  
Energy Method ◽  
Coulomb Friction ◽  
High Speed ◽  
Admissible Velocity ◽  
High Speed Impact ◽  
Dynamic Forces ◽  
Very High

A study is made of three methods of estimating die loads in impact forging: By approximate solution of the equations of equilibrium; by an energy method, assuming plane sections remain plane; and using the energy method in association with a kinematically admissible velocity field. Results are given for die pressures and die loads for axisymmetric and plane-strain forging of disks and slabs with smooth dies, perfectly rough dies, and for the case of Coulomb friction.

Hybrid composite shaft of High-Speed Rotor-Bearing System - A rotor dynamics preview

2020 ◽  
pp. 1-23
Author(s):  
Thimothy Harold Gonsalves ◽  
Mohan Kumar Garje Channabasappa ◽  
Ramesh Motagondanahalli Rangarasaiah
Keyword(s):  
Hybrid Composite ◽  
High Speed ◽  
Rotor Dynamics ◽  
System A ◽  
Composite Shaft ◽  
Rotor Bearing ◽  
Bearing System

Theory and Guidelines to Proper Coupling Design for Rotor Dynamics Considerations

1984 ◽  
Vol 106 (1) ◽  
pp. 129-138 ◽  
Author(s):  
R. G. Kirk ◽  
R. E. Mondy ◽  
R. C. Murphy
Keyword(s):  
High Speed ◽  
Field Data ◽  
Material Selection ◽  
Rotor Dynamics ◽  
Test Case ◽  
Additional Test ◽  
Gear Mesh ◽  
Type Design ◽  
Standard Design ◽  
Proper Material

The use of couplings for high-speed turbocompressors or pumps is essential to transmit power from the driver. Typical couplings are either of the lubricated gear or dry diaphragm type design. Gear couplings have been the standard design for many years and recent advances in power and speed requirements have pushed the standard design criteria to the limit. Recent test stand and field data on continuous lube gear type couplings have forced a closer examination of design tolerances and concepts to avoid operational instabilities. Two types of mechanical instabilities are reviewed in this paper: (1) entrapped fluid, and (2) gear mesh instability resulting in spacer throw-out onset. Test and results of these types of instabilities and other directly related problems are presented together with criteria for proper coupling design to avoid these conditions. An additional test case discussed shows the importance of proper material selection and processing and what can happen to an otherwise good design.

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