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Journal articles on the topic 'Synchronous thermal instability'

Author: Grafiati

Published: 10 March 2023

Last updated: 31 July 2025

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1

Balbahadur, A. C., and R. G. Kirk. "Part II—Case Studies for a Synchronous Thermal Instability Operating in Overhung Rotors." International Journal of Rotating Machinery 10, no. 6 (2004): 477–87. http://dx.doi.org/10.1155/s1023621x04000478.

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In Part I, a theoretical model was developed for a synchronous thermal instability that is caused by differential viscous shearing in bearings of overhung rotors. This second part used computer programs, which were based on the theoretical model, to examine various case studies that pertain to this thermal instability. Both plain and tilting pad journal bearing rotors were examined and good agreement was found between the theoretical predictions and the practical results.

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2

Balbahadur, A. C., and R. G. Kirk. "Part I—Theoretical Model for a Synchronous Thermal Instability Operating in Overhung Rotors." International Journal of Rotating Machinery 10, no. 6 (2004): 469–75. http://dx.doi.org/10.1155/s1023621x04000466.

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Atheoretical model has been developed for a synchronous thermal instability that is caused by differential viscous shearing in bearings of overhung rotors. This model employs an unbalance threshold criterion for instability instead of utilizing a traditional frequency-domain stability analysis. The current model will be used to investigate several case studies for both plain and tilting pad journal bearing rotors in the second part of this article.

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3

Singh, A. Narain, W. Doorsamy, and W. A. Cronje. "Thermal Instability Analysis of a Synchronous Generator Rotor using Direct Mapping." SAIEE Africa Research Journal 109, no. 1 (2018): 4–14. http://dx.doi.org/10.23919/saiee.2018.8531795.

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4

Bhadauria, Beer S., Atul K. Srivastava, Nirmal C. Sacheti, and Pallath Chandran. "Gravity Modulation of Thermal Instability in a Viscoelastic Fluid Saturated Anisotropic Porous Medium." Zeitschrift für Naturforschung A 67, no. 1-2 (2012): 1–9. http://dx.doi.org/10.5560/zna.2011-0045.

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The present paper deals with a thermal instability problem in a viscoelastic fluid saturating an anisotropic porous medium under gravity modulation. To find the gravity modulation effect, the gravity field is considered in two parts: a constant part and an externally imposed time-dependent periodic part. The time-dependent part of the gravity field, which can be realized by shaking the fluid, has been represented by a sinusoidal function. Using Hill’s equation and the Floquet theory, the convective threshold has been obtained. It is found that gravity modulation can significantly affect the st

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5

Balbahadur, A., and R. Kirk. "Part I?Theoretical Model for a Synchronous Thermal Instability Operating in Overhung Rotors." International Journal of Rotating Machinery 10, no. 6 (2004): 469–75. http://dx.doi.org/10.1080/10236210490504021.

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6

Balbahadur, A., and R. Kirk. "Part II?Case Studies for a Synchronous Thermal Instability Operating in Overhung Rotors." International Journal of Rotating Machinery 10, no. 6 (2004): 477–87. http://dx.doi.org/10.1080/10236210490504067.

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7

Scirè, Daniele, Giuseppe Lullo, and Gianpaolo Vitale. "Self-Heating Induced Instability of a Non-Linear Inductor in a SMPS: a Case Study." Renewable Energy and Power Quality Journal 21, no. 1 (2023): 656–61. http://dx.doi.org/10.24084/repqj21.440.

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This paper proposes a case study to show that the non-linear operation of a power inductor in a SMPS can induce instability of the control system leading to overheating of the inductor beyond its allowable temperature and to an excessive peak of the maximum current. The case study is performed by a commercial ferrite inductor employed in a synchronous boost converter encompassing a control system to adjust the duty cycle, assuring a constant output voltage. The thermal transient is described by the time domain waveforms and thermal images.

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Yoshida, Yoshiki, Yoshifumi Sasao, Kouichi Okita, Satoshi Hasegawa, Mitsuru Shimagaki, and Toshiaki Ikohagi. "Influence of Thermodynamic Effect on Synchronous Rotating Cavitation." Journal of Fluids Engineering 129, no. 7 (2007): 871–76. http://dx.doi.org/10.1115/1.2745838.

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Synchronous rotating cavitation is known as one type of cavitation instability, which causes synchronous shaft vibration or head loss. On the other hand, cavitation in cryogenic fluids has a thermodynamic effect on cavitating inducers because of thermal imbalance around the cavity. It improves cavitation performances due to delay of cavity growth. However, relationships between the thermodynamic effect and cavitation instabilities are still unknown. To investigate the influence of the thermodynamic effect on synchronous rotating cavitation, we conducted experiments in which liquid nitrogen was

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9

Olsson, Karl-Olof. "Some Unusual Cases of Rotor Instability." Journal of Vibration and Acoustics 125, no. 4 (2003): 477–81. http://dx.doi.org/10.1115/1.1606692.

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In the paper presented here three peculiar cases of rotor instability are presented. The first is a tilting-pad bearing used as an intershaft bearing in a two-spool gas turbine. It was initially chosen for its good stability properties. However, in a deeper study it was found that those benefits are greatly reduced when both inner shaft and outer bearing are rotating. The second case comprises a turbine which showed a very strange performance with vibrations alternating between heavy and mild amplitudes. The periods were a couple of minutes long. After a more elaborate instrumentation was inst

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10

Bhadauria, B. S. "Unsteady Heating of Rayleigh-Benard Convection." Zeitschrift für Naturforschung A 59, no. 4-5 (2004): 266–74. http://dx.doi.org/10.1515/zna-2004-4-511.

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The linear thermal instability of a horizontal fluid layer with time-periodic temperature distribution is studied with the help of the Floquet theory. The time-dependent part of the temperature has been expressed in Fourier series. Disturbances are assumed to be infinitesimal. Only even solutions are considered. Numerical results for the critical Rayleigh number are obtained at various Prandtl numbers and for various values of the frequency. It is found that the disturbances are either synchronous with the primary temperature field or have half its frequency. - 2000 Mathematics Subject Classif

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11

Liu, Hui, Jianxi Ren, Xinyue Dai, et al. "Evolution Law of Acoustic–Thermal Effect of Freeze–Thaw Sandstone Failure Based on Coupling of Multivariate Monitoring Information." Sustainability 15, no. 12 (2023): 9611. http://dx.doi.org/10.3390/su15129611.

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The instability and failure of rock that has been frozen and thawed cause serious rock engineering accidents in cold regions. Exploring the precursor information of freeze–thaw rock failure is of great theoretical value and engineering significance. Real-time uniaxial compression acoustic thermal monitoring experiments were conducted on freeze–thaw sandstone, and non-contact rock fracture precursor warning indicators were proposed. According to the coupled analysis of acoustic–thermal monitoring information, a precursor information chain for freeze–thaw rocks was established in time and space,

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12

Hu, Qilong, Min Zhu, and Jiangang Yang. "Study on Thermal Unstable Vibration of Rotor under Journal Whirl with Large Amplitude in Journal Bearing." International Journal of Rotating Machinery 2020 (January 25, 2020): 1–12. http://dx.doi.org/10.1155/2020/1980759.

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To investigate the thermal unstable vibration caused by journal whirls with large amplitude in journal bearing, an analysis model of lubricant film thickness is established. The journal surface temperature distribution is solved, and the reason for journal surface temperature difference appearance and its influence on rotor vibration are analyzed. Taking a turbogenerator as an example, the journal surface temperature difference and the induced rotor thermal bending under synchronous whirl in the bearing are calculated. Meanwhile, an engineering vibration fault with its treatment is presented.

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13

OR, A. C., and R. E. KELLY. "The effects of thermal modulation upon the onset of Marangoni–Bénard convection." Journal of Fluid Mechanics 456 (April 9, 2002): 161–82. http://dx.doi.org/10.1017/s0022112001007510.

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The effects of thermal modulation with time on the thermocapillary instability of a thin horizontal fluid layer with a deformable free surface are investigated on the basis of linear stability theory. First, a sinusoidal heating with a mean component is applied at the lower wall, corresponding to boundary conditions either in the form of prescribed temperature or heat flux. For finite-wavelength convection the thermal modulation exerts a strong effect, giving rise to a family of looped regions of instability corresponding to alternating synchronous or subharmonic responses. In the case of pres

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14

Varlamov, Ilya, Stanislav Parnikov, Igor Ievenko, Dmitry Baishev, and Kazuo Shiokawa. "Registration of synchronous geomagnetic pulsations and proton aurora during the substorm on March 1, 2017." EPJ Web of Conferences 254 (2021): 02012. http://dx.doi.org/10.1051/epjconf/202125402012.

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Data of synchronous geomagnetic pulsations and proton aurora registrations were analyzed during the substorm on March 1, 2017 at Zhigansk (L=4.5, induction magnetometer), Maimaga (L=4, all-sky imager and Yakutsk (L = 3.3, induction magnetometer) stations, simultaneously with satellite measurement of EMIC waves. Ground-based registration of proton aurora is very difficult due to the fact that their intensity is much lower than the aurora intensity caused by precipitations of electrons, but in the event of substorm activity at the zenith of Maimaga station, a narrow (1 degree in latitude) proton

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15

Duc Tung, Doan, Le Van Dai, and Le Cao Quyen. "Subsynchronous Resonance and FACTS-Novel Control Strategy for Its Mitigation." Journal of Engineering 2019 (July 14, 2019): 1–14. http://dx.doi.org/10.1155/2019/2163908.

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The subsynchronous resonance (SSR) is an important problem in the power system, and especially the series compensated transmission lines may cause SSR in the turbine generators, such that it leads to the electrical instability at subsynchronous frequencies and potential turbine-generator shaft failures. Taking the Vietnamese Vungang thermal plants as an example, a shaft failure of Vungang I thermal power unit has occurred on November 24, 2015, due to SSR. The main cause for this failure is a resonance caused by the series capacitors on the 500 kV grid. This paper analyzes the SSR based on the

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16

Tyulkina, I. V., and D. S. Goldobin. "Synchronization of convective currents of a two-component fluid in adjacent porous cells." ВЕСТНИК ПЕРМСКОГО УНИВЕРСИТЕТА. ФИЗИКА, no. 2 (2023): 59–68. http://dx.doi.org/10.17072/1994-3598--2023-2-59-68.

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In this work, we study the Soret-driven convection of a two-component fluid in adjacent rectangu-lar cells of a porous medium heated from below in the presence of a gravitational field. In each cell, a long-wavelength oscillatory instability is possible; it can be described by means of phase reduction, which makes it possible to study the synchronization of currents. The horizontal bounda-ries of the cells are assumed to be impenetrable (including for impurities), the heat flux is assumed to be fixed. The vertical boundaries have low thermal conductivity. Fluid motions are described by the Dar

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17

Shahani, Z. A., A. A. Hashmani, and M. M. Shaikh. "Steady State Stability Analysis and Improvement using Eigenvalues and PSS: A Case Study of a Thermal Power Plant in Jamshoro, Pakistan." Engineering, Technology & Applied Science Research 10, no. 1 (2020): 5301–6. http://dx.doi.org/10.48084/etasr.3318.

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The efficient handling and distribution of electrical power consist one of the most complex and appealing research problems. Due to the interconnection of different power plants and intensity of load, which gradually changes due to continuous change in load on generating units, careful treatment of the small disturbances in a power system which may lead to severe disturbance is necessary. Stability is an essential part in electrical power system operation and control. The stability problem is related with the behavior of synchronous machine after the power system is subjected to trouble. This

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Shahani, Z. A., A. A. Hashmani, and M. M. Shaikh. "Steady State Stability Analysis and Improvement using Eigenvalues and PSS: A Case Study of a Thermal Power Plant in Jamshoro, Pakistan." Engineering, Technology & Applied Science Research 10, no. 1 (2020): 5301–6. https://doi.org/10.5281/zenodo.3659630.

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The efficient handling and distribution of electrical power consist one of the most complex and appealing research problems. Due to the interconnection of different power plants and intensity of load, which gradually changes due to continuous change in load on generating units, careful treatment of the small disturbances in a power system which may lead to severe disturbance is necessary. Stability is an essential part in electrical power system operation and control. The stability problem is related with the behavior of synchronous machine after the power system is subjected to trouble. This

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19

Huang, Wei, Suwei Zhai, Xuegang Lu, et al. "Ultra-Low Frequency Oscillation in a Thermal Power System Induced by Doubly-Fed Induction Generators with Inertia Control." Processes 13, no. 5 (2025): 1368. https://doi.org/10.3390/pr13051368.

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Ultra-low frequency oscillation has been regarded as a typical instability issue in power systems consisting of hydro turbine synchronous generators due to the water hammer phenomenon. However, the increasing installation of renewable power generators gradually changes the stability mechanisms within multiple frequency bands. In this digest, a new kind of ultra-low frequency oscillation caused by doubly-fed induction generators (DFIGs) equipped with a df/dt controller in a thermal power generation system is introduced. To reveal the underlying mechanism, the motion equation model of the DFIG i

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20

Li, Min, Xiaodi Wang, Fang Liu, Xiaming Guo, Dawei Chen, and Yunfeng Wen. "Assessment of Regulation Capacity Requirements for Sending-End Grids Considering Frequency Security." Energies 18, no. 13 (2025): 3577. https://doi.org/10.3390/en18133577.

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With the large-scale integration of converter-based renewable energy into power systems and the large-scale construction of HVDC, risks associated with supply–demand imbalance and post-contingency frequency instability of sending-end power grids have significantly escalated. This paper proposes a novel method for evaluating the regulation capacity requirements of sending-end grids, addressing both normal-state power balance and post-disturbance frequency security. In normal states, multiple flexible metrics that can quantify the supply–demand imbalance trend are introduced. Then, thermal power

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21

Ginzburg, Anna I., Andrey G. Kostianoy, Nickolay A. Sheremet, Dmitry M. Soloviev, Symbat E. Koibakova, and Samal Syrlybekkyzy. "Mesoscale Water Dynamics and Chlorophyll-a/TSM/SST Distributions off the Eastern Coast of the Middle Caspian." Ecologica Montenegrina 85 (July 14, 2025): 40–65. https://doi.org/10.37828/em.2025.85.3.

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The study of seasonal changes in water dynamics and the corresponding distributions of chlorophyll-a (Chl-a) and Total Suspended Matter (TSM) in the Kazakhstan sector of the eastern coast of the Middle Caspian Sea (42–45°N, 49.5°N – coastline on the East) was carried out based on a joint analysis of synchronous satellite-derived maps of sea surface temperature (SST), concentration of Chl-a and Water Leaving Radiance (0.551 µm) in different months of the year (July–December 2023 and January–March 2022). It has been established that in summer, with pronounced density (thermal) stratification of

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22

Lin, Feng. "(Battery Division Early Career Award Sponsored by Neware Technology Limited) Design, Synthesis, and Characterization of Cathode Microstructures in Lithium Batteries." ECS Meeting Abstracts MA2022-02, no. 3 (2022): 210. http://dx.doi.org/10.1149/ma2022-023210mtgabs.

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The propagation of redox reactions governs the electrochemical properties of battery materials and their critical performance metrics in battery cells. The recent research progress, especially aided by advanced analytical techniques, has revealed that incomplete and heterogeneous redox reactions prevail in many electrode materials. Advanced high-capacity cathode materials are mostly polycrystalline materials that exhibit complex charge distribution (the valence state distribution of the redox-active cations) due to the presence of numerous constituting grains and grain boundaries. The redox re

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23

ZHAO, Yanjun, Guohua NI, Wei LIU, et al. "Dynamic characteristics of multi-arc thermal plasma in four types of electrode configurations." Plasma Science and Technology 24, no. 5 (2022): 055407. http://dx.doi.org/10.1088/2058-6272/ac4ee7.

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Abstract The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers. Combined with a high-speed camera and an oscilloscope, which acquire optical and electric signals synchronously, the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated. Also, the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method. It is found that the ca

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24

Guo, Zenglin, and Gordon Kirk. "Morton Effect Induced Synchronous Instability in Mid-Span Rotor–Bearing Systems—Part I: Mechanism Study." Journal of Vibration and Acoustics 133, no. 6 (2011). http://dx.doi.org/10.1115/1.4004665.

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The Morton Effect in rotor-bearing systems may lead to an unstable operation. In Part I, the mechanism of the Morton Effect–induced thermal instability in the mid-span rotor systems is studied. First, the equivalent thermal induced imbalance is introduced and its magnitude and directions are assumed, to represent the viscous thermal effect on the rotor systems. Then, the simplified rotor and bearing models are adopted for the derivation of analytical expressions. The results show that there exists a threshold of instability due to the Morton Effect in the mid-span rotors. Based on the assumpti

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25

Shin, Dongil, Alan B. Palazzolo, and Xiaomeng Tong. "Squeeze Film Damper Suppression of Thermal Bow-Morton Effect Instability." Journal of Engineering for Gas Turbines and Power 142, no. 12 (2020). http://dx.doi.org/10.1115/1.4048602.

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Abstract The Morton effect (ME) is a synchronous vibration problem in turbomachinery caused by the nonuniform viscous heating around the journal circumference, and its resultant thermal bow (TB) and ensuing synchronous vibration. This paper treats the unconventional application of the SFD for the mitigation of ME-induced vibration. Installing a properly designed squeeze film damper (SFD) may change the rotor's critical speed location, damping, and deflection shape, and thereby suppress the vibration caused by the ME. The effectiveness of the SFD on suppressing the ME is tested via linear and n

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26

Lee, Jung Gu, and Alan Palazzolo. "Morton Effect Cyclic Vibration Amplitude Determination for Tilt Pad Bearing Supported Machinery." Journal of Tribology 135, no. 1 (2012). http://dx.doi.org/10.1115/1.4007884.

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This paper presents theoretical models and simulation results for the synchronous, thermal transient, instability phenomenon known as the Morton effect. A transient analysis of the rotor supported by tilting pad journal bearing is performed to obtain the transient asymmetric temperature distribution of the journal by solving the variable viscosity Reynolds equation, a 2D energy equation, the heat conduction equation, and the equations of motion for the rotor. The asymmetric temperature causes the rotor to bow at the journal, inducing a mass imbalance of overhung components such as impellers, w

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27

Shin, Dongil, and Alan B. Palazzolo. "Tilting Pad Journal Bearing Misalignment Effect on Thermally Induced Synchronous Instability (Morton Effect)." Journal of Tribology 143, no. 3 (2020). http://dx.doi.org/10.1115/1.4048164.

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Abstract This paper investigates the influence of misaligned journal bearing effects on the thermally induced rotor instability (Morton effect “ME”) problem. The Morton effect is caused by uneven viscous heating of the journal in a fluid film bearing, which causes thermal bending, especially in rotors with an overhung disc or coupling weight. The thermally induced bending in the shaft may cause a vibration instability, which results in an excessive level of synchronous vibration. Previous research focused on parametric studies of the rotor and bearing design parameters, including overhung mass

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28

Saravanan, S., and T. Sivakumar. "Thermovibrational Instability in a Fluid Saturated Anisotropic Porous Medium." Journal of Heat Transfer 133, no. 5 (2011). http://dx.doi.org/10.1115/1.4003013.

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A comprehensive investigation is made to understand the effect of harmonic vibration on the onset of convection in a horizontal anisotropic porous layer heated either from below or from above. The layer is subject to vertical mechanical vibrations of arbitrary amplitude and frequency. The porous medium is assumed to be both mechanically and thermally anisotropic, and Brinkman’s law is invoked to model the momentum balance. Both continued fraction and Hill’s infinite determinant methods are used to determine the convective instability threshold with the aid of Floquet theory. The synchronous an

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29

Tong, Xiaomeng, Alan Palazzolo, and Junho Suh. "A Review of the Rotordynamic Thermally Induced Synchronous Instability (Morton) Effect." Applied Mechanics Reviews 69, no. 6 (2017). http://dx.doi.org/10.1115/1.4037216.

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The Morton effect (ME) is a thermally induced instability problem that most commonly appears in rotating shafts with large overhung masses and supported by fluid-film bearings. The time-varying thermal bow, due to the asymmetric journal temperature distribution, may cause intolerable synchronous vibrations that exhibit a hysteresis behavior with respect to rotor speed. First discovered by Morton in the 1970s and theoretically analyzed by Keogh and Morton in the 1990s, the ME is still not fully understood by industry and academia experts. Traditional rotordynamic analysis generally fails to pre

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Guo, Zenglin, and Gordon Kirk. "Morton Effect Induced Synchronous Instability in Mid-Span Rotor–Bearing Systems, Part 2: Models and Simulations." Journal of Vibration and Acoustics 133, no. 6 (2011). http://dx.doi.org/10.1115/1.4004666.

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The mechanism of the Morton Effect induced synchronous instability has been discussed in Part 1, using an assumption of isotropic linear bearings. The second part of the current study will now focus on the more realistic systems, mid-span rotors supported by the hydrodynamic journal bearings. First, the models to calculate the thermal bending of the shaft and the temperature distribution across the journal surface are established. This can be used to calculate the equivalent thermal imbalance. The calculations of the temperature difference and its equivalent thermal imbalance using hydrodynami

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31

Suh, Junho, and Alan Palazzolo. "Three-Dimensional Thermohydrodynamic Morton Effect Analysis—Part II: Parametric Studies." Journal of Tribology 136, no. 3 (2014). http://dx.doi.org/10.1115/1.4027310.

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This paper presents simulation results corresponding with the theoretical Morton effect model explained in Part I, where the 3D finite element models of bearing, shaft, and fluid film are adopted. In addition, it explains how thermal bow induced imbalance force develops in the spinning journal with time and how the vibration level is affected by the thermal bow vector. Shaft asymmetric thermal expansion induced by nonuniform journal heating is simulated, which is one of the unique contributions of this research. The effect of changes in: (1) thermal boundary condition around the pad, (2) lubri

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Suh, Junho, and Alan Palazzolo. "Three-Dimensional Thermohydrodynamic Morton Effect Simulation—Part I: Theoretical Model." Journal of Tribology 136, no. 3 (2014). http://dx.doi.org/10.1115/1.4027309.

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The present study is focused on accurate prediction of the Morton effect problem including journal asymmetric heating and the corresponding long period amplitude oscillations using a nonlinear time transient rotor-dynamic simulation. This paper presents a theoretical model of thermal induced synchronous instability problems in a nonlinear rotor–bearing system, and suggests a new computational algorithm for the nonlinear transient analysis of the Morton effect where the dynamic and thermal problems are combined. For the analysis of the Morton effect problem, a variable viscosity Reynolds equati

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Tong, Xiaomeng, and Alan Palazzolo. "Double Overhung Disk and Parameter Effect on Rotordynamic Synchronous Instability—Morton Effect—Part I: Theory and Modeling Approach." Journal of Tribology 139, no. 1 (2016). http://dx.doi.org/10.1115/1.4033888.

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The Morton effect (ME) is a thermally induced instability problem that most commonly appears in rotating shafts with large overhung masses, outboard of the bearing span. The time-varying thermal bow due to the asymmetric journal temperature distribution may cause intolerable synchronous vibrations that exhibit a hysteresis behavior with respect to rotor speed. The fully nonlinear transient method designed for the ME prediction, in general, overhung rotors is proposed with the capability to perform the thermoelastohydrodynamic analysis for all the bearings and model the rotor thermal bow at bot

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Shin, Dongil, and Alan B. Palazzolo. "Tilting Pad Bearing Pivot Friction and Design Effects on Thermal Bow-Induced Rotor Vibration." Journal of Tribology 143, no. 12 (2021). http://dx.doi.org/10.1115/1.4050427.

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Abstract The Morton effect (ME) is a thermally induced vibration problem observed in a rotor supported by hydrodynamic bearings. The journal’s synchronous orbiting induces nonuniform viscous heating on its circumference, and the ensuing thermal bow often causes unacceptable vibration levels in the rotor. This paper investigates the influence of the tilting pad journal bearing (TPJB)’s pivot design on the severity and instability speed range of ME vibration. Simulations are conducted with two different types of pivots: cylindrical (CYL) and spherical (SPH), which produce different pad degrees-o

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Kim, Tae Ho, and Luis San Andrés. "Effect of Side Feed Pressurization on the Dynamic Performance of Gas Foil Bearings: A Model Anchored to Test Data." Journal of Engineering for Gas Turbines and Power 131, no. 1 (2008). http://dx.doi.org/10.1115/1.2966421.

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Comprehensive modeling of gas foil bearings (GFBs) anchored to reliable test data will enable the widespread usage of these bearings into novel high speed turbomachinery applications. GFBs often need a forced cooling gas flow, axially fed through one end of the bearing, for adequate thermal management. This paper presents rotordynamic response measurements on a rigid rotor supported on GFBs during rotor speed run-up and coastdown tests with the GFBs supplied with increasing feed gas pressures to 2.8bars. Rotor speed run-up tests to 35krpm show that the bearing end side feed gas pressurization

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Fan, Xiaohua, Yixiu Gan, Miaowen Tan, and Wenhe Wang. "Theoretical study on thermal decomposition mechanism of 1-nitroso-2-naphthol." Scientific Reports 12, no. 1 (2022). http://dx.doi.org/10.1038/s41598-022-24638-z.

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Abstract1-nitroso-2-naphthol has thermal instability of thermal decomposition, spontaneous combustion and even explosion. Its thermal decomposition characteristics were tested by synchronous thermal analyzer (TGA/DSC); The activation energy of the thermal decomposition process was calculated by Kissinger method; The infrared absorption characteristic spectra of the gas products produced in the thermal decomposition process were measured by TGA/DSC-FTIR, and the thermal decomposition reaction process was speculated. The results show that the initial temperature (Tonset) of TGA exothermic decomp

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Li, Qian, Weiguo Dong, Duanwei He, et al. "Oxidation and graphitization of micro‐grained diamond in vacuum and atmosphere." Journal of the American Ceramic Society, June 16, 2025. https://doi.org/10.1111/jace.20670.

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AbstractThermal stability of diamond is crucial for its applications. However, conflicting reports exist regarding the sequence of oxidation and transformation and the temperature range at which non‐diamond phases form. In addition, systematic and quantitative studies are insufficient. This study systematically investigates the oxidation and graphitization behavior of micro‐grained diamond powder after heat treatment in air and vacuum environments. The temperature ranges and volume fraction for non‐diamond phase formation were estimated, and the oxidation and non‐diamond phase transition tempe

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Yu, Haifeng, Yueqiang Cao, Long Chen, et al. "Surface enrichment and diffusion enabling gradient-doping and coating of Ni-rich cathode toward Li-ion batteries." Nature Communications 12, no. 1 (2021). http://dx.doi.org/10.1038/s41467-021-24893-0.

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AbstractCritical barriers to layered Ni-rich cathode commercialisation include their rapid capacity fading and thermal runaway from crystal disintegration and their interfacial instability. Structure combines surface modification is the ultimate choice to overcome these. Here, a synchronous gradient Al-doped and LiAlO2-coated LiNi0.9Co0.1O2 cathode is designed and prepared by using an oxalate-assisted deposition and subsequent thermally driven diffusion method. Theoretical calculations, in situ X-ray diffraction results and finite-element simulation verify that Al3+ moves to the tetrahedral in

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Childs, Dara W., and Rohit Saha. "A New, Iterative, Synchronous-Response Algorithm for Analyzing the Morton Effect." Journal of Engineering for Gas Turbines and Power 134, no. 7 (2012). http://dx.doi.org/10.1115/1.4005973.

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Morton Effect problems involve the steady increase in rotor synchronous-response amplitudes due to differential heating across a fluid-film bearing that is induced by synchronous response. The present work presents a new computational algorithm for analyzing the Morton Effect. Previous approaches were based on Eigen or Nyquist analyses for stability studies and predicted an onset speed of instability. The present algorithm starts with a steady state elliptical orbit produced by the initial imbalance distribution, which is decomposed into a forward-precessing circular orbit and a backwards-prec

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Li, Hanlou, Penghui Guo, Jing Wang, et al. "Thermally Controlled Synthesis of Cr2(NCN)3/CrN Heterostructured Composite Anodes for High‐Performance Li‐Ion Batteries." Batteries & Supercaps, May 16, 2024. http://dx.doi.org/10.1002/batt.202400223.

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Cr2(NCN)3 features high specific capacity and fast electrical conductivity, making it a promising anode candidate for Li‐ion batteries. However, inherent chemical and structural metastability severely restrict its capacity output and cycle life, resulting in unsatisfactory battery performance. Here we use its thermal instability characteristic and propose a thermal controlled structural coordination strategy to in‐situ construct a Cr2(NCN)3/CrN heterostructure. Systematic studies reveal the thermodynamic structural evolution of Cr2(NCN)3 under precise temperature regulation, as well as the ess

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Yin, Shan, Enyuan Wang, Zhonghui Li, et al. "Experimental testing and research on the physical response law of magnetic field signal during coal deformation and failure process." Physics of Fluids 37, no. 7 (2025). https://doi.org/10.1063/5.0279202.

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The instability and failure of coal rock generate acoustic, electrical, thermal, magnetic, and other physical signals. The discovery and application of some new phenomena and laws will promote the development of coal rock dynamic disaster monitoring and warning technology. In this paper, an experimental magnetic field (MF) monitoring system for coal instability failure is developed, the MF and acoustic emission (AE) signals of coal under loading are monitored synchronously, and the relationship among the MF, coal failure, and AE is analyzed. The results show that coal can generate MF during de

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Yang, Jongin, and Alan Palazzolo. "Three-Dimensional Thermo-Elasto-Hydrodynamic Computational Fluid Dynamics Model of a Tilting Pad Journal Bearing—Part II: Dynamic Response." Journal of Tribology 141, no. 6 (2019). http://dx.doi.org/10.1115/1.4043350.

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Part II presents a novel approach for predicting dynamic coefficients for a tilting pad journal bearing (TPJB) using computational fluid dynamics (CFD) and finite element method (FEM), including fully coupled elastic deflection, heat transfer, and fluid dynamics. Part I presented a similarly novel, high fidelity approach for TPJB static response prediction which is a prerequisite for the dynamic characteristic determination. The static response establishes the equilibrium operating point values for eccentricity, attitude angle, deflections, temperatures, pressures, etc. The stiffness and dampi

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