Application of coupled analysis methods for prediction of blast-induced dominant vibration frequency

Abstract With the massive use of buddle risers and pipelines in deep-water oil production industries, the demand to focus on the research of interference effects of dual pipe has been greatly enhanced. This paper presents interference experiments of dual flexible pipes with unequal diameters under uniform flow with Reynolds numbers ranging from 1.8E3 to 1.1E4. The pipe with larger diameter was set to be the upstream pipe. Various tandem arrangements with wall surface-to-wall surface distances being 3D to 8D were tested, where D is the smaller pipe diameter. Fiber Bragg grating (FBG) strain sensors were used to measure both in-plane and out-of-plane strain responses. Modal superposition method was applied to reconstruct IL mean displacement. Significant interference effect was found under the condition that wall-to-wall gap is smaller than 8D, where CF and IL vibration frequency ratio of downstream pipe equals to 1.0 and IL mean displacement gets smaller compared to those of single pipe in isolation. Moreover, a special ‘capture’ phenomenon, that the dominant vibration frequency and mode of downstream pipe were as the same as that of the upstream pipe subjecting to the uniform flows, was found when wall-to-wall distances were 4D and 8D.

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Towards the Integration of Analysis and Design of Mooring Systems and Risers: Part II — Studies on a DICAS System

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 1 ◽

10.1115/omae2002-28151 ◽

2002 ◽

Cited By ~ 8

Author(s):

Fabri´cio Nogueira Correa ◽

Stael Ferreira Senra ◽

Breno Pinheiro Jacob ◽

Isai´as Quaresma Masetti ◽

Ma´rcio Martins Mourelle

Keyword(s):

Motion Analysis ◽

Production Systems ◽

Companion Paper ◽

Coupled Analysis ◽

Mooring Line ◽

Mooring System ◽

Analysis And Design ◽

Design Methodologies ◽

Analysis Methods ◽

Campos Basin

The objective of this paper is to study different analysis methodologies for the design of floating production systems. The main issues are the use of uncoupled and coupled analysis methods, and the integration in the analysis and design of the mooring system and the risers. This paper is a companion to another paper also presented in the OMAE2002 Conference [1]. That paper describes a “basic” classic, uncoupled methodology, and comments on some refinements in the representation of the behavior of the lines in the motion analysis of the vessel. Comments regarding the introduction of some level of integration between mooring line and riser behavior are also presented in the companion paper [1], and these issues are illustrated with studies applying some of the considered design methodologies to the P-18 semi-submersible platform in Campos basin. The present paper proceeds describing some hybrid methodologies that combine coupled and uncoupled analysis tools, and illustrates their application to a DICAS system for deepwater applications in Campos basin.

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A Study on the Electromagnetic–Temperature Coupled Analysis Method for In-Wheel Motors

Applied Sciences ◽

10.3390/app9204206 ◽

2019 ◽

Vol 9 (20) ◽

pp. 4206 ◽

Cited By ~ 1

Author(s):

Di Tan ◽

Yanshou Wu ◽

Kun Yang ◽

Zhichang Qin ◽

Chao Ma

Keyword(s):

Element Model ◽

Relative Difference ◽

Maximum Temperature ◽

Coupled Analysis ◽

Analysis Method ◽

Coupling Analysis ◽

Unidirectional Coupling ◽

Analysis Methods ◽

Bidirectional Coupling ◽

Coupling Factors

As the core component of in-wheel motor-driven electric vehicles, the in-wheel motor (IWM) directly affects the driving/braking performance of each driving wheel and the driving performance of the vehicle. The IWM operation involves a coupling of multi-fields, including the electromagnetic, temperature, flow, and mechanical fields, which influence each other. It is necessary to study coupling analysis methods to obtain accurate and consistent results. In this paper, a 15 kW in-wheel motor is taken as the research object. Based on the finite element model of the IWM, the coupling factors between the electromagnetic and temperature field, and the influence trend of coupling factors on the two fields are investigated. On this basis, considering the strong coupling factors obtained from the above analysis, the unidirectional coupling and bidirectional coupling analysis methods are used to analyze the electromagnetic–temperature characteristics of the IWM, and the comparative results between the two methods are discussed. It was found that the results showed the temperature of the IWM calculated by the bidirectional coupling method was higher than that obtained by the unidirectional coupling analysis method. The maximum temperature of stator windings calculated by bidirectional coupling was 7.1% higher than that calculated by unidirectional coupling analysis, and the effect on the relative difference of torque could reach 7.4%. Bidirectional coupling can more accurately reflect the variation of variables in the fields and the prediction of motor performance in the process of motor operation. The progress made in the electromagnetic–temperature coupled analysis method can provide a theoretical basis and useful ideas for the multi-fields coupling analysis of IWMs.

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