Comparison of Computational Generalized and Standard Eigenvalue Solutions of Rotating Systems

2018 ◽  
pp. 187-194
Author(s):  
Ali Tatar ◽  
Loic Salles ◽  
Alexander H. Haslam ◽  
Christoph W. Schwingshackl
Keyword(s):  
Rotating Systems

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

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.

Unsteady Flow Phenomena in Rotating Centrifugal Impeller Passages

1970 ◽  
Vol 92 (1) ◽  
pp. 65-71 ◽  
Author(s):  
E. Lennemann ◽  
J. H. G. Howard
Keyword(s):  
Unsteady Flow ◽  
Secondary Flow ◽  
Centrifugal Impeller ◽  
Bubble Flow ◽  
Hydrogen Bubble ◽  
Visualization Technique ◽  
Rotating Systems ◽  
Flow Phenomena ◽  
Relative Flow ◽  
Zero Flow

The phenomena of unsteady relative flow observed in a centrifugal impeller passage running at part capacity and zero flow are discussed. The mechanisms of passage stall for a shrouded and unshrouded impeller are investigated and a qualitative correlation is developed for the influence of secondary flow and inducer flow on the passage stall. The hydrogen bubble flow visualization technique is extended to higher velocities and rotating systems and provides the method for obtaining the experimental results.

scholarly journals Rotor Dynamics Analysis of Rotating Machine Systems Using Artificial Neural Networks

2003 ◽  
Vol 9 (4) ◽  
pp. 255-262 ◽  
Author(s):  
M. Kalkat ◽  
Ş. Yıldırım ◽  
I. Uzmay
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Vertical Direction ◽  
Rotor Dynamics ◽  
Experimental Setup ◽  
Dynamics Analysis ◽  
Rotating Machine ◽  
Rotating Systems ◽  
Machine Systems ◽  
Vibration Parameters

Adirect-coupled rotor system was designed to analyze the dynamic behavior of rotating systems in regard to vibration parameters. The vibration parameters are amplitude, velocity, and acceleration in the vertical direction. The system consisted of a machine analyzer, shaft, disk, master-trend software, and power unit. Four different points were detected and measured by the experimental setup. The vibration parameters were found and saved from master-trend software. These parameters were employed as the desired parameters of the network. A neural network is designed for analyzing a system's vibration parameters. The results showed that the network could be used as an analyzer of such systems in experimental applications.

scholarly journals The Antonov problem for rotating systems

2003 ◽  
Vol 654 (3) ◽  
pp. 427-444 ◽  
Author(s):  
A. De Martino ◽  
E.V. Votyakov ◽  
D.H.E. Gross
Keyword(s):  
Rotating Systems

The macrodynamics of α-effect dynamos in rotating fluids

1975 ◽  
Vol 67 (3) ◽  
pp. 417-443 ◽  
Author(s):  
W. V. R. Maekus ◽  
M. R. E. Proctor
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Magnetic Energy ◽  
Finite Amplitude ◽  
Small Scale ◽  
Past Study ◽  
Ohmic Loss ◽  
General Will ◽  
Rotating Systems ◽  
Stellar Magnetic Fields

Past study of the large-scale consequences of forced small-scale motions in electrically conducting fluids has led to the ‘α-effect’ dynamos. Various linear kinematic aspects of these dynamos have been explored, suggesting their value in the interpretation of observed planetary and stellar magnetic fields. However, large-scale magnetic fields with global boundary conditions can not be force free and in general will cause large-scale motions as they grow. I n this paper the finite amplitude behaviour of global magnetic fields and the large-scale flows induced by them in rotating systems is investigated. In general, viscous and ohmic dissipative mechanisms both play a role in determining the amplitude and structure of the flows and magnetic fields which evolve. In circumstances where ohmic loss is the principal dissipation, it is found that determination of a geo- strophic flow is an essential part of the solution of the basic stability problem. Nonlinear aspects of the theory include flow amplitudes which are independent of the rotation and a total magnetic energy which is directly proportional to the rotation. Constant a is the simplest example exhibiting the various dynamic balances of this stabilizing mechanism for planetary dynamos. A detailed analysis is made for this case to determine the initial equilibrium of fields and flows in a rotating sphere.

Simulation of Cooling Systems in Gas Turbines

1996 ◽  
Vol 118 (2) ◽  
pp. 301-306 ◽  
Author(s):  
G. Ebenhoch ◽  
T. M. Speer
Keyword(s):  
Gas Turbines ◽  
Path Following ◽  
Cooling Systems ◽  
Turbine Engine ◽  
Rotating Systems ◽  
Entire Flow ◽  
Flow Pressure ◽  
The One ◽  
Single Flow ◽  
Flow Element

The design of cooling systems for gas turbine engine blades and vanes calls for efficient simulation programs. The main purpose of the described program is to determine the complete boundary condition at the coolant side to support a temperature calculation for the solid. For the simulation of convection and heat pick up of the coolant flow, pressure loss, and further effects to be found in a rotating frame, the cooling systems are represented by networks of nodes and flow elements. Within each flow element the fluid flow is modeled by a system of ordinary differential equations based on the one-dimensional conservation of mass, momentum, and energy. In this respect, the computer program differs from many other network computation programs. Concerning cooling configurations in rotating systems, the solution for a single flow element or the entire flow system is not guaranteed to be unique. This is due to rotational forces in combination with heat transfer and causes considerable computational difficulties, which can be overcome by a special path following method in which the angular velocity is selected as the parameter of homotopy. Results of the program are compared with measurements for three applications.

Computational Aeroacoustics for Rotating Systems with Application to an Axial Fan

AIAA Journal ◽  
2017 ◽  
Vol 55 (11) ◽  
pp. 3831-3838 ◽  
Author(s):  
Manfred Kaltenbacher ◽  
Andreas Hüppe ◽  
Aaron Reppenhagen ◽  
Florian Zenger ◽  
Stefan Becker
Keyword(s):  
Computational Aeroacoustics ◽  
Axial Fan ◽  
Rotating Systems

Moments of Inertia of Freely Rotating Systems

1956 ◽  
Vol 103 (6) ◽  
pp. 1773-1775 ◽  
Author(s):  
H. J. Lipkin ◽  
A. de-Shalit ◽  
I. Talmi
Keyword(s):  
Moments Of Inertia ◽  
Rotating Systems
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