Transient Coupling Model of Plasma and Laser Field in Water

2016 ◽  
Vol 52 (8) ◽  
pp. 1-9 ◽  
Author(s):  
Chong Zhang ◽  
Jian Lu ◽  
Hongchao Zhang ◽  
Zhonghua Shen ◽  
Xiaowu Ni
Keyword(s):  
Laser Field ◽  
Coupling Model ◽  
Transient Coupling

Experimental and numerical study of the pre-tilted journal bearing

2019 ◽  
Vol 234 (7) ◽  
pp. 1075-1091 ◽  
Author(s):  
Jintao Mo ◽  
Ying Luo ◽  
Jia Liu ◽  
Dapeng Yan ◽  
Xungang Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Numerical Study ◽  
Design Method ◽  
Coupling Model ◽  
Heavy Load ◽  
Attitude Angle ◽  
Shaft Misalignment ◽  
Rotating Shafts ◽  
Transient Coupling

Hydrodynamic journal bearings are key components for supporting the rotating shafts in high-speed machinery. The shaft misalignment due to the heavy load, the thermal effects, and the manufacturing errors may introduce problems during running such as rub-impact. So the journal bearing with a pre-tilted angle has been introduced in this paper to solve the problem. The pre-tilted journal bearing is allowed to be adjusted to the proper attitude angle according to the tilt of the shaft under working condition. Thus ensuring the symmetric pressure distribution of the bearing and avoiding the rub-impact. A test rig has been designed and built to validate the working effect of the pre-tilted journal bearing. A design method for the pre-tilted journal bearing has also been introduced in this paper. In this method, a transient coupling model is adopted to precisely calculate the attitude angle of the bearing and a special dynamic mesh method is used to guarantee the mesh quality with arbitrary motion of the journal.

SATOUMI APPROACH FOR REALIZING SUSTAINABLE COASTAL USE IN A RIASTYPE BAY: A CASE OF SHIZUGAWA BAY IN SANRIKU COAST HIT BY THE HUGE TSUNAMI ON 11 MARCH 2011

2017 ◽  
Author(s):  
Teruhisa Komatsu ◽  
Teruhisa Komatsu ◽  
Shuji Sasa ◽  
Shuji Sasa ◽  
Shigeru Montani ◽  
...  
Keyword(s):  
Local Governments ◽  
Minor Element ◽  
Coupling Model ◽  
Sanriku Coast ◽  
High Productivity ◽  
Biological Coupling ◽  
Miyagi Prefecture ◽  
Human Use ◽  
A Minor ◽  
Aquaculture Facilities

Rias-type bays are one of the most common coasts in Japan where aquacultures have been active due to sheltered geological shape with a deep bottom. The huge tsunami hit Sanriku Coast consisting of open rias-type bays near the epicenter facing Pacific Ocean on 11 March 2011. For recovering Sanriku Coast, it is important to include sustainability in its program. Satoumi is defined as the human use and management of coastal seas for high productivity while maintaining high biodiversity. Therefore, we proposed Satoumi approach to an open rias-type bay, Shizugawa Bay, in southern Sanriku Coast. We conducted scientific researches on mapping of coastal habitats and aquaculture facilities, hydrography, and material flows of nutrients, a minor element (Fe) and organic matters in the bay including those from the rivers and from the offshore waters. At the same time, Committee for Shizugawa Bay Management of Fishermen’s Cooperative of Miyagi Prefecture decided to decrease in aquaculture facilities for sustainable development of aquaculture. Based on these data, a physical-biological coupling model was used for calculating the number of aquaculture facilities that are suitable not only for yields but also for environments. These researches were established on strong collaborations among a fishermen’s’ cooperative, local governments and scientists. Results of this practice may help to realize sustainable coastal use of a rias-type bay.

An alternative model of the vibronic coupling in octahedral complexes

1988 ◽  
Vol 53 (6) ◽  
pp. 1134-1140
Author(s):  
Martin Breza ◽  
Peter Pelikán
Keyword(s):  
Linear Regression ◽  
Alternative Model ◽  
Potential Surface ◽  
Analytical Formula ◽  
Coupling Model ◽  
Regression Method ◽  
Vibronic Coupling ◽  
Linear Regression Method ◽  
Active Systems ◽  
Jahn Teller

It is suggested that for some transition metal hexahalo complexes, the Eg-(a1g + eg) vibronic coupling model is better suited than the classical T2g-(a1g + eg) model. For the former, alternative model, the potential constants in the analytical formula are evaluated from the numerical map of the adiabatic potential surface by using the linear regression method. The numerical values for 29 hexahalo complexes of the 1st row transition metals are obtained by the CNDO/2 method. Some interesting trends of parameters of such Jahn-Teller-active systems are disclosed.

scholarly journals A Fusion Algorithm for Online Reliability Evaluation of Microgrid Inverter IGBT

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1294 ◽  
Author(s):  
Chuankun Wang ◽  
Yigang He ◽  
Chenyuan Wang ◽  
Xiaoxin Wu ◽  
Lie Li
Keyword(s):  
Aging Process ◽  
Short Term Memory ◽  
Coupling Model ◽  
Reliability Evaluation ◽  
Junction Temperature ◽  
Stable Operation ◽  
Practical Case ◽  
Fusion Algorithm ◽  
Insulated Gate Bipolar Transistor ◽  
Damage Degree

Due to the diversity of distributed generation sources, microgrid inverters work under complex and changeable conditions. The core device of inverters, an insulated gate bipolar transistor (IGBT), bears a large amount of thermal stress impact, so its reliability is related to the stable operation of the microgrid. The effect of the IGBT aging process cannot be considered adequately with the existing reliability evaluation methods, which have not yet reached the requirements of online evaluation. This paper proposes a fusion algorithm for online reliability evaluation of microgrid inverter IGBT, which combines condition monitoring and reliability evaluation. Firstly, based on the microgrid inverter topology and IGBT characteristics, an electrothermal coupling model is established to obtain junction temperature data. Secondly, the segmented long short-term memory (LSTM) algorithm is studied, which can accurately predict the aging process of the IGBT and judge the aging state via the limited monitoring data. Then, the parameters of the electrothermal coupling model are corrected according to the aging process. Besides, the fusion algorithm is applied to the practical case. Finally, the data comparison verifies the feasibility of the fusion algorithm, whose cumulative damage degree and estimated life error are 5.10% and 5.83%, respectively.

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