Vapour bubble growth within a viscous mixture non-Newtonian fluid between two-phase turbulent flow

In this paper, the growth of a vapour bubble in superheated water for two-phase turbulent flow is studied. The growth problem is formulated by mass and momentum equations under physical assumptions between two finite boundaries. The analytical solution is obtained in terms of the vapour bubble radius. The bubbly growth is affected by thermal diffusivity, superheating, and the Péclet number. The fact that the scale of the bubble is larger than the scale of the turbulence in the mixture surrounding the growing bubble is considered. The previous models of growth for laminar flow are obtained as a special cases of the present model for some values of the parameters a, b, n, and φ0, respectively.

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Effect of Heat Transfer on the Growing Bubble with the Nanoparticles/Water Nanofluids in Turbulent Flow

Mathematical Modelling and Engineering Problems ◽

10.18280/mmep.080112 ◽

2021 ◽

Vol 8 (1) ◽

pp. 95-102

Author(s):

Ahmed K. Abu-Nab ◽

Ali F. Abu-Bakr

Keyword(s):

Heat Transfer ◽

Temperature Distribution ◽

Turbulent Flow ◽

Bubble Growth ◽

Bubble Dynamics ◽

Pure Water ◽

Theoretical Data ◽

Superheated Liquid ◽

Two Phase ◽

The Mathematical Model

This paper is devoted to study the effect of heat transfer on the temperature distribution in a superheated liquid during the growth of vapour bubbles immersed in different types of nanoparticles/water nanofluids between two-phase turbulent flow. The mathematical model is formulated and solved analytically depending on Scriven's theory and using the modification of the method of the similarity parameters between two finite boundaries. The characteristics of vapour bubble growth and temperature distribution are obtained by using the thermo-physical properties of nanoparticles nanofluids. The results indicate that the nanoparticle volume concentration reduces the bubble growth process under the effect of heat transfer. The better agreements are achieved, for bubble dynamics in turbulent nanofluid using the appropriate numerical and theoretical data for the values of concentration rate of nanoparticles χ=0,0.2,0.4. The temperature distribution surrounding the regime of bubble growth in pure water is more intensive than in other cases of Al2O3/H2O, Fe3O4/H2O and CuO/H2O nanofluids in turbulent flow. A Comparison of the current solution with previous works is carried out and discussed.

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LIMITATIONS OF THE STOCHASTIC APPROACH IN TWO-PHASE TURBULENT FLOW CALCULATIONS

Atomization and Sprays ◽

10.1615/atomizspr.v6.i2.50 ◽

1996 ◽

Vol 6 (2) ◽

pp. 211-225 ◽

Cited By ~ 3

Author(s):

Keh-Chin Chang ◽

Wen-Jing Wu ◽

Muh-Rong Wang

Keyword(s):

Turbulent Flow ◽

Stochastic Approach ◽

Two Phase

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Model of a turbulent flow of a two-phase liquid with an uneven distributed phase concentration in a horizontal pipe

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1047/1/012021 ◽

2021 ◽

Vol 1047 (1) ◽

pp. 012021

Author(s):

Kh Sh Ilhamov ◽

D Z Narzullaev ◽

Sh T Ilyasov ◽

B A Abdurakhmanov ◽

K K Shadmanov

Keyword(s):

Turbulent Flow ◽

Two Phase ◽

Horizontal Pipe ◽

Phase Concentration ◽

Phase Liquid

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Discussion: “Squeeze Film Dynamics of Two-Phase Seals: Part II—Turbulent Flow” (Yasuna, J. A., and Hughes, W. F., 1994, ASME J. Tribol., 116, pp. 479–487)

Journal of Tribology ◽

10.1115/1.2928869 ◽

1994 ◽

Vol 116 (3) ◽

pp. 487-487

Author(s):

P. Basu

Keyword(s):

Turbulent Flow ◽

Squeeze Film ◽

Two Phase

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Vapour bubble growth and detachment at the wall of shear flow

Heat and Mass Transfer ◽

10.1007/s00231-007-0287-y ◽

2007 ◽

Vol 45 (7) ◽

pp. 847-855 ◽

Cited By ~ 12

Author(s):

G. Duhar ◽

G. Riboux ◽

C. Colin

Keyword(s):

Shear Flow ◽

Bubble Growth ◽

Vapour Bubble

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Effect of Pressure on Bubble Growth Within Liquid Droplets at the Superheat Limit

Journal of Heat Transfer ◽

10.1115/1.3245195 ◽

1982 ◽

Vol 104 (4) ◽

pp. 750-757 ◽

Cited By ~ 34

Author(s):

C. T. Avedisian

Keyword(s):

Vapor Bubble ◽

Bubble Growth ◽

High Speed ◽

Ambient Pressure ◽

Organic Liquid ◽

Liquid Droplets ◽

Growth Data ◽

Two Phase ◽

Photographic Evidence ◽

Good Agreement

A study of high-pressure bubble growth within liquid droplets heated to their limits of superheat is reported. Droplets of an organic liquid (n-octane) were heated in an immiscible nonvolatile field liquid (glycerine) until they began to boil. High-speed cine photography was used for recording the qualitative aspects of boiling intensity and for obtaining some basic bubble growth data which have not been previously reported. The intensity of droplet boiling was found to be strongly dependent on ambient pressure. At atmospheric pressure the droplets boiled in a comparatively violent manner. At higher pressures photographic evidence revealed a two-phase droplet configuration consisting of an expanding vapor bubble beneath which was suspended a pool of the vaporizing liquid. A qualitative theory for growth of the two-phase droplet was based on assuming that heat for vaporizing the volatile liquid was transferred across a thin thermal boundary layer surrounding the vapor bubble. Measured droplet radii were found to be in relatively good agreement with predicted radii.

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High Speed Imaging and Two-Phase Flow Patterns During Flow Boiling in a Single Microchannel

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2008-62316 ◽

2008 ◽

Author(s):

Jacqueline Barber ◽

Khellil Sefiane ◽

David Brutin ◽

Lounes Tadrist

Keyword(s):

High Speed ◽

Two Phase Flow ◽

Flow Boiling ◽

Pressure Sensors ◽

Flow Patterns ◽

Bubble Nucleation ◽

Phase Flow ◽

Vapour Bubble ◽

Two Phase ◽

Over Time

Boiling in microchannels remains elusive due to the lack of full understanding of the mechanisms involved. A powerful tool in achieving better comprehension of the mechanisms is detailed imaging and analysis of the two phase flow at a fundamental level. We induced boiling in a single microchannel geometry (hydraulic diameter 727 μm), using a refrigerant FC-72, to investigate several flow patterns. A transparent, metallic, conductive deposit has been developed on the exterior of rectangular microchannels, allowing simultaneous uniform heating and visualisation to be conducted. The data presented in this paper is for a particular case with a uniform heat flux of 4.26 kW/m2 applied to the microchannel and inlet liquid mass flowrate, held constant at 1.33×10−5 kg/s. In conjunction with obtaining high-speed images and videos, sensitive pressure sensors are used to record the pressure drop profiles across the microchannel over time. Bubble nucleation, growth and coalescence, as well as periodic slug flow, are observed in the test section. Phenomena are noted, such as the aspect ratio and Reynolds number of a vapour bubble, which are in turn correlated to the associated pressure drops over time. From analysis of our results, images and video sequences with the corresponding physical data obtained, it is possible to follow visually the nucleation and subsequent both ‘free’ and ‘confined’ growth of a vapour bubble over time.

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A comparative study of MHD fluid-particle suspension induced by metachronal wave under the effects of lubricated walls

International Journal of Modern Physics B ◽

10.1142/s0217979221502040 ◽

2021 ◽

pp. 2150204

Author(s):

Mubbashar Nazeer ◽

Farooq Hussain ◽

Laiba Shabbir ◽

Adila Saleem ◽

M. Ijaz Khan ◽

...

Keyword(s):

Heat Transfer ◽

Magnetic Fields ◽

Multiphase Flow ◽

Thermal Radiation ◽

Newtonian Fluid ◽

Closed Form Solution ◽

Casson Fluid ◽

Form Solution ◽

Phase Flow ◽

Two Phase

In this paper, the two-phase flow of non-Newtonian fluid is investigated. The main source of the flow is metachronal waves which are caused by the back and forth motion of cilia attached to the opposite walls of the channel. Magnetohydrodynamics (MHD) of Casson fluid experience the effects of transverse magnetic fields incorporated with the slippery walls of the channel. Thermal effects are examined by taking Roseland’s approximation and application of thermal radiation into account. The heat transfer through the multiphase flow of non-Newtonian fluid is further, compared with Newtonian bi-phase flow. Since the main objective of the current study is to analyze heat transfer through an MHD multiphase flow of Casson fluid. The two-phase heated flow of non-Newtonian fluid is driven by cilia motion results in nonlinear and coupled differential equations which are transformed and subsequently, integrated subject to slip boundary conditions. A closed-form solution is eventually obtained form that effectively describes the flow dynamics of multiphase flow. A comprehensive parametric study is carried out which highlights the significant contribution of pertinent parameters of the heat transfer of Casson multiphase flow. It is inferred that lubricated walls and magnetic fields hamper the movement of multiphase flow. It is noted that a sufficient amount of additional thermal energy moves into the system, due to the Eckert number and Prandtl number. While thermal radiation acts differently by expunging the heat transfer. Moreover, Casson multiphase flow is a more suitable source of heat transfer than Newtonian multiphase flow.

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Analysis of the Motion and Deformation of a Bubble Rising in a Viscoelastic Fluid

Volume 2: Fora ◽

10.1115/fedsm2006-98363 ◽

2006 ◽

Author(s):

Shriram Pillapakkam ◽

Pushpendra Singh ◽

Denis L. Blackmore ◽

Nadine Aubry

Keyword(s):

Velocity Field ◽

Newtonian Fluid ◽

Viscoelastic Fluid ◽

Bubble Radius ◽

Polymer Concentration ◽

Deborah Number ◽

Two Phase ◽

Bubble Volume ◽

Recirculation Zones ◽

Bubble Rising

A finite element code based on the level set method is developed for performing two and three dimensional direct numerical simulations (DNS) of viscoelastic two-phase flow problems. The Oldroyd-B constitutive equation is used to model the viscoelastic liquid and both transient and steady state shapes of bubbles in viscoelastic buoyancy driven flows are studied. The influence of the governing dimensionless parameters, namely the Capillary number (Ca), the Deborah Number (De) and the polymer concentration parameter c, on the deformation of the bubble is also analyzed. Our simulations demonstrate that the rise velocity oscillates before reaching a steady value. The shape of the bubble, the magnitude of velocity overshoot and the amount of damping depend mainly on the parameter c and the bubble radius. Simulations also show that there is a critical bubble volume at which there is a sharp increase in the bubble terminal velocity as the increasing bubble volume increases, similar to the behavior observed in experiments. The structure of the wake of a bubble rising in a Newtonian fluid is strikingly different from that of a bubble rising in a viscoelastic fluid. In addition to the two recirculation zones at the equator of the bubble rising in a Newtonian fluid, two more recirculation zones exist in the wake of a bubble rising in viscoelastic fluids which influence the shape of a rising bubble. Interestingly, the direction of motion of the fluid a short distance below the trailing edge of a bubble rising in a viscoelastic fluid is in the opposite direction to the direction of the motion of the bubble, thus creating a “negative wake”. In this paper, the velocity field in the wake of the bubble, the effect of the parameters on the velocity field and their influence on the shape of the bubble are also investigated.

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