Full conjugate heat transfer modelling for steam turbines in transient operations

Fadl, Mohamed; Stein, P. vom; He, L.

doi:10.1016/j.ijthermalsci.2017.10.025

Cited by 12 publications

(4 citation statements)

References 25 publications

(35 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this respect then, the method considers the influence of the low frequency variations on the high frequency components of the solution but neglects the converse. This assumption, that has shown to have no impact on the accuracy of the solution ( [11], [15], [16], [17], [18]) holds the key to the computational savings allowed by the method. Governing equations U component is obtained through a suitable lowpass filtering operation.…”

Section: Multi-scale Modelling (Msm)mentioning

confidence: 99%

“…Through manipulation of the Navier-Stokes and solid conduction equations, as well as appropriate treatment of the solid-fluid interface boundary condition, the method allows to march in time the solid solution with a time-step that is not bound by the fluid domain. The method has been shown to allow considerable speed-up with respect to a monolithic fully-coupled (FC) solution-where the same solver is used for both Navier-Stokes and solid conduction, with energy conservation at the fluid-solid interface being implicitly satisfied-without loss of accuracy ( [15], [16], [17], [18]).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Validity of Scaling Transient Conjugate Heat Transfer Characteristics

Maffulli

Marinescu²,

2020

Journal of Engineering for Gas Turbines and Power

Self Cite

View full text Add to dashboard Cite

Accurate prediction of unsteady thermal loads is of paramount importance in several engineering disciplines and applications. Performing time-accurate unsteady conjugate heat transfer (CHT) simulations presents considerable challenges due to the markedly different time scales between the solid and fluid domains. Two methods have been recently proposed, aimed at addressing this issue: multiscale modeling (MSM) and equalized time-scales (ET). The former is based on the separation of the disparate short and long temporal scales of the solution and subsequent averaging of the flow/energy equations. In the latter, the equalization of the time scales is achieved through manipulation of the solid's thermal properties. Both methods are very appealing due to the possibility of being easily implemented on an existing solver. It becomes, thus, relevant to assess their performance and/or limitations. This paper work presents a comparative study of the two methods for the prediction of transient thermal load, first using a simplified case of a solid body with uniform temperature, then through the investigation of the prewarming phase of a steam turbine. Both methods are then compared against a reference baseline fully coupled (FC) CHT solution. The results show how the MSM allows greater accuracy and robustness with considerable saving in computational cost with respect to the baseline solution.

show abstract

Section: Multi-scale Modelling (Msm)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the Validity of Scaling Transient Conjugate Heat Transfer Characteristics

Maffulli

Marinescu²,

2020

Journal of Engineering for Gas Turbines and Power

Self Cite

View full text Add to dashboard Cite

show abstract

“…The deformation of a blade is very complicated due to its variable cross section and torsional shape, the complex and nonlinear steam flow field around it and their coupling effect (Choi et al, 1999;Chaibakhsh and Ghaffari, 2008;Wood and Morton, 1984;Fadl et al, 2018). Therefore, it is difficult to obtain accurate deformation of a blade using calculations and analyses based on theoretical formulas (Moheban and Young, 1985).…”

Section: Introductionmentioning

confidence: 99%

“…With the development of the finite element method and computational fluid dynamics technology (Bhagi et al, 2018;Prabhunandan and Byregowda, 2018;Shukla and Harsha, 2015;Brahimi and Ouibrahim, 2016;Hashemian et al, 2020;Jang et al, 2015;Francesco et al, 2017), iterative solutions of the pre-deformation design method based on numerical calculations have gradually been used in blade analysis and optimal design (Noori Rahim Abadi et al, 2017;Obert and Cinnella, 2017;Pascoa et al, 2009;Hou et al, 2019;Li et al, 2019;Jiang et al, 2019;Yi et al, 2020a, b). With these methods, the construction of a hot shape and the correction of a cold shape are alternately and repeatedly executed in the pre-deformation design process.…”

Section: Introductionmentioning

confidence: 99%

Scheme optimization for a turbine blade under multiple working conditions based on the entropy weight vague set

Zhou

Wang

et al. 2021

Mech. Sci.

View full text Add to dashboard Cite

Abstract. The deformation of blades under complex loads of multiple working conditions will reduce the energy conversion efficiency. To reduce the deviation of the blade shape in practical working conditions, a combination and optimization method of blade design schemes under multiple working conditions, based on the entropy weight vague sets, is proposed. The sensitivity of each working condition index is analyzed based on the information entropy, and the satisfaction degree of the design scheme based on the design requirements and experiences is described with the vague set. The matching degree of different design schemes for multiple working conditions is quantified according to the scoring function. The combination and optimization of the design scheme are verified by numerical simulation analysis. The results show that the proposed design scheme has a smaller blade shape deviation than the traditional design scheme under multiple working conditions.

show abstract