Modelling of Dynamics of Aerosols in Near-Wall Turbulent Flows and Particle Deposition in Pipes

Zaichik, L. I.; Nigmatulin, B. I.; Pershukov, V. A.

doi:10.1016/b978-0-444-81811-9.50011-1

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…All the combinations of friction for the wall and the free surface give the same tendency: height decreases with steam velocity. On top of that, the combination of the friction wall equation (17) with (19) and the interfacial friction equation (24) with (28) predicts, for all measured steam velocities, the height of the film within the experiment uncertainty of measurements. The model is thus capable of describing accurately the height of a highly sheared liquid film on a flat plate using the expression of Spedding and Hand for the wall friction (17) with (19) and with the expression of Ihnatowicz (24) for the friction at the free surface.…”

Section: Model Validationmentioning

confidence: 76%

“…By setting a classical steam turbine wetness (up to 15%) and steam flow rate, a value of the mass term can be estimated. Another more precise approach consists in extracting the local droplet number and radius from the steam field resolved for a wet steam turbine [10], [14], and to translate these data into a deposition rate using Zaichik's correlation [28].…”

Section: Mass Termmentioning

confidence: 99%

“…Indeed, the fact that the liquid film is less viscous for lower pressure and that the film is highly sheared, lead to a stability issue which is handled by lowering the CFL. Figures 9, 10 and 11 give the experiment data (bar range) and compare the effect of the closure relations used for the wall friction ((17) with (18) and (19), and (20)) and for the free surface ((24) with (25), (26), (27), (28)). All the combinations of friction for the wall and the free surface give the same tendency: height decreases with steam velocity.…”

Section: Model Validationmentioning

confidence: 99%

See 2 more Smart Citations

A Model for Liquid Films in Steam Turbines and Preliminary Validations

Simon

Marcelet

Hérard

et al. 2016

Volume 8: Microturbines, Turbochargers and Small Turbomachines; Steam Turbines

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Liquid films in steam turbines, present in usual operating conditions, play a large but poorly understood part in the wetness-born troubles (power losses and erosion). More knowledge is needed to estimate their impacts and lessen their effects. The aim of this paper is to propose and verify a model to predict these liquid films. This model is based on modified Shallow-Water equations (integral formulation). It takes into account inertia, mass transfer, gravity, gas and wall frictions, pressure, surface tension, droplet impacts, rotational effects and is unsteady. A 2D code has been developed to implement this model. A part of the model has been verified with analytical solutions (Riemann problems and inclined lake at rest), has been confronted with the linear stability of falling liquid film and has been validated with the experiment of Hammitt et al. [1] which involves a sheared film under low-pressure steam turbine conditions.

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Section: Model Validationmentioning

confidence: 76%

Section: Mass Termmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

See 1 more Smart Citation

A Model for Liquid Films in Steam Turbines and Preliminary Validations

Simon

Marcelet

Hérard

et al. 2016

Volume 8: Microturbines, Turbochargers and Small Turbomachines; Steam Turbines

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“…For instance the Zaichick correlation can be used for fog droplets deposition. For more details on this correlation, the reader can refer to Zaichik et al 18,19 Numerical schemes…”

Section: ðA2þmentioning

confidence: 99%

Development of a model for thin films and numerical sensitivity tests

Simon

Dorey

Lance

2018

Proceedings of the Institution of Mechanical Engineers, Part A:

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Because the unsteady behavior of liquid films in steam turbines is a key point for additional friction losses and atomization process (that leads to coarse water generation), the development of a dedicated model has been found necessary. A twodimensional computational fluid dynamics code for unstructured mesh is being developed using the finite volume method to simulate this thin liquid film. The aim is to predict the formation of the waves in the film since it is suspected to be a key parameter for friction and atomization. Applied as a first step to a plane plate, the code has been verified in a onedimensional version with analytical solutions and is tested in low-pressure turbine steam conditions. Falling films computations (without gas shear stress) show that the model is capable to reproduce the waves' shape of experiments from the literature. With steam under low-pressure turbine conditions, and compared to experimental data from the University of Michigan, the model including shear stress and surface tension provides good results for heights. Sensitivity calculations have been undergone showing the crucial influence of the surface tension and the generation of solitary waves for high velocities is captured by the code. The effect of gravity is also quantified.

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References

2008

Particles in Turbulent Flows

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Modelling of Dynamics of Aerosols in Near-Wall Turbulent Flows and Particle Deposition in Pipes

Cited by 6 publications

References 14 publications

A Model for Liquid Films in Steam Turbines and Preliminary Validations

A Model for Liquid Films in Steam Turbines and Preliminary Validations

Development of a model for thin films and numerical sensitivity tests

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