scholarly journals Discussion: “Transient Dynamics of a Tilting Pad Gas Bearing System” (Castelli, V., and McCabe, J. T., 1967, ASME J. Lubr. Technol., 89, pp. 499–507)

1967 ◽  
Vol 89 (4) ◽  
pp. 508-509
Author(s):  
W. J. Love
Keyword(s):  
Transient Dynamics ◽  
Tilting Pad ◽  
Gas Bearing ◽  
Bearing System

Transient Dynamics of a Tilting Pad Gas Bearing System

1967 ◽  
Vol 89 (4) ◽  
pp. 499-507 ◽  
Author(s):  
V. Castelli ◽  
J. T. McCabe
Keyword(s):  
Steady State ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Degree Of Freedom ◽  
Performance Characteristics ◽  
Experimental Results ◽  
Transient Dynamics ◽  
Tilting Pad ◽  
Gas Bearing ◽  
Bearing System

A method for obtaining the performance characteristics of a rotor-tilting pad gas lubricated journal bearing system by solving the appropriate dynamics equations together with the time-transient Reynolds’ equation is outlined. Results for a 4 degree of freedom and an 18 degree of freedom system are given. Comparison with steady-state and experimental results are also discussed.

Dynamic Characteristics of a Tilting-Pad Bearing System for High Expansion Ratio Expander

1994 ◽  
pp. 909-916 ◽  
Author(s):  
Jinhao Qiu ◽  
Toshiyuki Takagi ◽  
Junji Tani ◽  
Akito Machida ◽  
Kazuhito Tsugawa ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Expansion Ratio ◽  
Tilting Pad ◽  
Bearing System

scholarly journals An alternative approach to match field production data from unconventional gas-bearing systems

2020 ◽  
Vol 17 (5) ◽  
pp. 1370-1388
Author(s):  
Zhi-Gang Zhang ◽  
Yan-Bao Liu ◽  
Hai-Tao Sun ◽  
Wei Xiong ◽  
Kai Shen ◽  
...  
Keyword(s):  
History Matching ◽  
Field Data ◽  
Ordos Basin ◽  
Production Data ◽  
Unconventional Gas ◽  
Alternative Approach ◽  
Matching Techniques ◽  
Gas Bearing ◽  
Bearing System ◽  
Automatic Computing

Abstract Nowadays, the unconventional gas-bearing system plays an increasingly important role in energy market. The performances of the current history-matching techniques are not satisfied when applied to such systems. To overcome this shortfall, an alternative approach was developed and applied to investigate production data from an unconventional gas-bearing system. In this approach, the fluid flow curve obtained from the field is the superposition of a series of Gaussian functions. An automatic computing program was developed in the MATLAB, and both gas and water field data collected from a vertical well in the Linxing Block, Ordos Basin, were used to present the data processing technique. In the reservoir study, the automatic computing program was applied to match the production data from a single coal seam, multiple coal seams and multiple vertically stacked reservoirs with favourable fitting results. Compared with previous approaches, the proposed approach yields better results for both gas and water production data and can calculate the contributions from different reservoirs. The start time of the extraction for each gas-containing unit can also be determined. The new approach can be applied to the field data prediction and designation for the well locations and patterns at the reservoir scale.

scholarly journals Nonlinear Dynamics Analysis of Tilting Pad Journal Bearing-Rotor System

2011 ◽  
Vol 18 (1-2) ◽  
pp. 45-52 ◽  
Author(s):  
Jiayang Ying ◽  
Yinghou Jiao ◽  
Zhaobo Chen
Keyword(s):  
Nonlinear Dynamics ◽  
System Dynamics ◽  
Journal Bearing ◽  
Rotor System ◽  
Moment Of Inertia ◽  
Dynamics Analysis ◽  
Tilting Pad ◽  
Rotor Bearing ◽  
Tilting Pad Journal Bearing ◽  
Bearing System

The nonlinear dynamics theory is increasingly applied in the dynamics analysis of tilting pad journal bearing-rotor system. However, extensive work on system dynamics done previously neglects the influence caused by the moment of inertia of the pad. In this paper, a comparison is made between the responses of the rotor in the bearings with and without pad inertia effect. Taking the Jeffcott rotor system as an example, the characteristics of bearing-rotor system, such as bifurcation diagram, cycle response, frequency spectrum, phase trajectories, and Poincaré maps, were attained within a certain rotation rate range. The pivotal oil-film force of tilting pad journal bearing was calculated by database method. The results directly demonstrate that considering the influence of the pad moment of inertia, system dynamics characteristics are found more complicated when rotor-bearing system works around natural frequency and system bifurcation is observed forward when rotor-bearing system works on high-speed range.

Numerical study on tilting pad journal gas bearing with variable stiffness springs

2015 ◽  
Vol 29 (8) ◽  
pp. 3059-3067 ◽  
Author(s):  
Shuangtao Chen ◽  
Shanju Yang ◽  
Quan Zhou ◽  
Yu Hou ◽  
Tianwei Lai
Keyword(s):  
Numerical Study ◽  
Variable Stiffness ◽  
Tilting Pad ◽  
Gas Bearing

Dynamic Forced Response of a Rotor-Hybrid Gas Bearing System Due to Intermittent Shocks

2009 ◽  
Author(s):  
Luis San Andre´s ◽  
Keun Ryu
Keyword(s):  
Natural Frequency ◽  
Fuel Efficiency ◽  
Forced Response ◽  
System Level ◽  
Jet Engines ◽  
Test Rig ◽  
Gas Bearings ◽  
Business Jet ◽  
Gas Bearing ◽  
Bearing System

Gas bearings in microturbomachinery (MTM) offer significant system level benefits, such as improved fuel efficiency, reduction in weight and number of components, extending life cycle and maintenance intervals, and reducing NOX emissions with a lower CO2 footprint. Emerging opportunities for gas bearings applications range from automotive turbochargers to engines for business jet aircraft, for example. Gas bearings, because of the inherently low gas viscosity, have low damping relative to oil-lubricated bearings and are prone to wear during rotor start-up and shut down procedures. The lack of damping brings concerns about rotor-gas bearing system robustness and endurance to tolerate shock induced loads, sudden while landing in jet engines, or intermittent in vehicles while moving across a rough terrain, for example. The paper demonstrates the reliability of a hybrid gas bearing system from rotor vibration measurements induced by sporadic shock loads acting on the base of a test rig and while the rotor is coasting down from a top speed of 60 krpm (1000 Hz). In the tests, (1) an electromagnetic pusher delivers impacts to the rig base, or (2) the whole rig is manually tilted and dropped. The test rig consists of a rigid rotor, 0.825 kg and 28.6 mm in diameter, supported on two flexure pivot tilting pad type, hybrid gas bearings, each with four pads and 60% pivot offset and 0.6 mm feeding holes. The bearings are supplied with feed pressures of 2.36, 3.72, and 5.08 bar (ab). Intermittent shocks, up to 30 g pk-pk and exciting a broad frequency range to 400 Hz, produce a remarkable momentary increase of the overall rotor response amplitude, up to 50 μm (pk-pk). The shocks readily excite the fundamental natural frequency of the rotor-bearing system (150–200 Hz), and on occasion the natural frequency (40 Hz) of the whole test rig. For operation at rotor speeds above the system critical speed, the rotor synchronous response is isolated; with transient motions induced by a shock, subsynchronous in whirl frequency, quickly disappearing. Full recovery takes place in ∼0.10 second. The measurements demonstrate that the hybrid gas bearings have enough damping to rapidly attenuate rotor transient motions and to dissipate the energy induced from intermittent shocks. Note that the shocks acted while the rotor traversed its critical speeds. The reliability of engineered gas bearings to forced transient events is no longer in question.

Sign in / Sign up

Export Citation Format

Share Document