Numerical study of coupled fluid–structure interaction for combustion system

Khatir, Zinedine; Pozarlik, Artur Krzysztof; Cooper, Richard K.; Watterson, John; Kok, Jacobus B.W.

doi:10.1002/fld.1701

Cited by 8 publications

(7 citation statements)

References 6 publications

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“…A Radial Basis Function (RBF) method [29], shown to be an effective design tool for industrial applications such as combustion systems [30] for instance, is employed to build the surrogate models of j , where a cubic radial power function is used to determine the weighting of points in the regression analysis at each point:…”

Section: Optimisation Strategymentioning

confidence: 99%

“…A Design of experiments (DOE) approach based on 2D LBM is used to generate 67 points uniformly spread within the design space (r, ) . Note that our computational results in section 3.2 below indicate a sufficiently strong correlation between the 2D LBM predictions and the (much more expensive) full 3D VOF predictions to justify this approach.A Radial Basis Function (RBF) method [29], shown to be an effective design tool for industrial applications such as combustion systems [30] for instance, is employed to build the surrogate models of j , where a cubic radial power function is used to determine the weighting of points in the regression analysis at each point:The RBF-based surrogate models for the jumping velocity j and heat flux, q are built by carrying out 2D LBM CFD calculations and solutions of Eq. (12) respectively at each of the DOE points and using these values to build surrogate models of their dependence on the design variables throughout the design space.…”

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confidence: 99%

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Dropwise condensation heat transfer process optimisation on superhydrophobic surfaces using a multi-disciplinary approach

Khatir

Kubiak

Jimack

et al. 2016

Applied Thermal Engineering

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Dropwise condensation has superior heat transfer efficiency than filmwise condensation; however condensate evacuation from the surface still remains a significant technological challenge. The process of droplets jumping, against adhesive forces, from a solid surface upon coalescence has been studied using both experimental and Computational Fluid Dynamics (CFD) analysis. Both Lattice Boltzmann (LBM) and Volume of Fluid (VOF) methods have been used to evaluate different kinematic conditions of coalescence inducing a jump velocity. In this paper, an optimisation framework for superhydrophobic surface designs is presented which uses experimentally verified high fidelity CFD analyses to identify optimal combinations of design features which maximise desirable characteristics such as the vertical velocity of the merged jumping droplet from the surface and energy efficiency. A Radial Basis Function (RBF)-based surrogate modelling approach using design of experiment (DOE) technique was used to establish near-optimal initial process parameters around which to focus the study. This multidisciplinary approach allows us to evaluate the jumping phenomenon for superhydrophobic surfaces for which several input parameters may be varied, so as to improve the heat transfer exchange rate on the surface during condensation. Reliable conditions were found to occur for droplets within initial radius range of r=20-40 m and static contact angle s~160º. Moreover, the jumping phenomenon was observed for droplets with initial radius of up to 500 m. Lastly, our study also reveals that a critical contact angle for droplets to jump upon coalescence is c~1 40º. KeywordsCondensation heat transfer, Super-hydrophobic surface, Jumping droplets velocity, Multi-disciplinary optimisation. IntroductionDrop-wise condensation processes, where condensation occurs through small droplets on a solid surface, has been demonstrated to significantly improve heat transfer rates in comparison to filmwise condensation (where a whole surface is covered by a thin film of liquid) [1,2]. Drop-wise condensation usually takes place on hydrophobic or super-hydrophobic surfaces as demonstrated by Boreyko and Chen [3]. One of the main technological challenges is to create such a surface, so as to allow condensation and evacuation of the droplets to take place in a continuous manner. Droplet coalescence is a complex physical phenomenon and optimisation of kinematic conditions leading to surface dewetting and jumping of droplets is of paramount importance for processes like heat transfer, de-icing, atmospheric water harvesting or dehumidification [4][5][6]. Dropwise condensation heat transfer performance can be enhanced by allowing condensed droplets to be removed rapidly from the surface to minimize the thermal barrier [7]. Recently, researchers showed that superhydrophobic surfaces provide a higher mobility of condensates, which may enhance the heat transfer performance [1][2][3][4][5][6][7]. Coalescence-induced jumping phenomena occur on superhydrophobic surfa...

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Section: Optimisation Strategymentioning

confidence: 99%

mentioning

confidence: 99%

Dropwise condensation heat transfer process optimisation on superhydrophobic surfaces using a multi-disciplinary approach

Khatir

Kubiak

Jimack

et al. 2016

Applied Thermal Engineering

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“…This shows that the application of helical strakes is able to reduce the amplitude and hence the vibration of the cylinder. The VIV suppression efficiency ratio of the helical strakes of the present study is 82.5 percent, which can calculated by: (5) where (A/D)max indicates the maximum amplitude ratio. Percentage as high as 93.1% is reported by Boubenider et al [17].…”

Section: Resultsmentioning

confidence: 69%

“…This initiates the exploration of fluid-structure interaction (FSI) software in predicting the VIV characteristic of a riser. Although FSI software is widely used in several applications such as combustion system [5,6] and arterial blood flow [7,8], its involvement on flow pass a circular riser/cylinder in three-dimensional is still rare. Several studies using twodimensional (2D) FSI simulation are found.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Vortex-Induced Vibration of Bare Cylinder and Cylinder Fitted with Helical Strakes

Lee¹,

Abu²,

Muhamad³

et al. 2017

MATEC Web Conf.

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Abstract. In the study, the vortex-induced vibration (VIV) of a cylinder fitted with and without helical strakes is investigated using fluid-structure interaction (FSI) software. The purpose is to predict the VIV characteristic of cylinder fitted with and without helical strakes. Fluid and structural solvers in commercial computational fluid dynamic (CFD) software were implemented as two-way FSI solvers to develop the simulation. A flexible circular cylinder of diameter, D = 0.018 m was tested. The pitch and height of the helical strakes were 10D and 0.10D, respectively. Existing experiment outputs of bare cylinder were used as benchmark to verify the simulated results. In overall, the simulation was able to predict the trend of the amplitude response and the mean drag coefficient. However, a slight over-prediction was noticed. It was also found that the helical strakes was able to reduce up to 60% of the VIV in water.

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“…Numerical simulations of fluid structure interaction problems can be found in many engineering and scientific applications [10,12]. In this work, the case in (Tab.1) is investigated.…”

Section: One-way Interactionmentioning

confidence: 99%

Numerical prediction of interaction between combustion, acoustics and vibration in gas turbines

Pozarlik

Kok

2008

The Journal of the Acoustical Society of America

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The turbulent flame in the lean combustion regime in a gas turbine combustor generates significant thermo-acoustic instabilities. The flame can amplify fluctuations in the released heat, and thus in the acoustic field as well. The induced pressure oscillations will drive vibrations of the combustor walls and burner parts. Stronger fluctuating pressure results in stronger fluctuations in the wall structure. Due to fatigue the remaining life time of the hard ware will be reduced significantly. This paper investigates modeling of acoustic oscillations and mechanical vibrations induced by lean premixed natural gas combustion. The mutual interaction of the combustion processes, induced oscillating pressure field in the combustion chamber, and induced vibration of the liner walls are investigated with numerical techniques. A partitioned procedure is used here: CFX-10 for the CFD analysis and Ansys-10 for the CSD analysis are coupled to give insight into a correlation between acoustic pressure oscillations and liner vibrations. These results will be compared with the available experimental data. The data are gathered in a purpose built 500 kW/5 bar premixed natural gas test rig.

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Numerical study of coupled fluid–structure interaction for combustion system

Cited by 8 publications

References 6 publications

Dropwise condensation heat transfer process optimisation on superhydrophobic surfaces using a multi-disciplinary approach

Dropwise condensation heat transfer process optimisation on superhydrophobic surfaces using a multi-disciplinary approach

Prediction of Vortex-Induced Vibration of Bare Cylinder and Cylinder Fitted with Helical Strakes

Numerical prediction of interaction between combustion, acoustics and vibration in gas turbines

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