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  • Experimental study on inter-particle acoustic forces

     Garcia Sabate, Anna; Gonzalez Cinca, Ricardo; Hoyos, Mauricio; Castro, Angelica
    Journal of the Acoustical Society of America
    Vol. 135, num. 3, p. 1056-1063
    DOI: 10.1121/1.4864483
    Date of publication: 2014-03-01
    Journal article

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    A method for the experimental measurement of inter-particle forces (secondary Bjerknes force) generated by the action of an acoustic field in a resonator micro-channel is presented. The acoustic radiation force created by an ultrasonic standing wave moves suspended particles towards the pressure nodes and the acoustic pressure induces particle volume oscillations. Once particles are in the levitation plane, transverse and secondary Bjerknes forces become important. Experiments were carried out in a resonator filled with a suspension composed of water and latex particles of different size (5-15 mu m) at different concentrations. Ultrasound was generated by means of a 2.5 MHz nominal frequency transducer. For the first time the acoustic force generated by oscillating particles acting on other particles has been measured, and the critical interaction distance in various cases has been determined. Inter-particle forces on the order of 10(-1)4 N have been measured by using this method. (C) 2014 Acoustical Society of America.

    A method for the experimental measurement of inter-particle forces (secondary Bjerknes force) generated by the action of an acoustic field in a resonator micro-channel is presented. The acoustic radiation force created by an ultrasonic standing wave moves suspended particles towards the pressure nodes and the acoustic pressure induces particle volume oscillations. Once particles are in the levitation plane, transverse and secondary Bjerknes forces become important. Experiments were carried out in a resonator filled with a suspension composed of water and latex particles of different size (5–15 lm) at different concentrations. Ultrasound was generated by means of a 2.5 MHz nominal frequency transducer. For the first time the acoustic force generated by oscillating particles acting on other particles has been measured, and the critical interaction distance in various cases has been determined. Inter-particle forces on the order of 10 14 N have been measured by using this method

  • SYT2012 - Final Report - Acoustic control of rising bubbles at different gravity levels

     Garcia Sabate, Anna; Gonzalez Cinca, Ricardo; Farrarons Clusella, Roger
    Date: 2013-02-20
    Report

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  • Heat storage and electricity generation in the Moon during the lunar night

     Climent Molina, Blai; Torroba Moreno, Oscar; Gonzalez Cinca, Ricardo; Ramachandran, Narayanan; Griffin, Michael D.
    Acta astronautica
    Vol. 93, p. 352-358
    DOI: 10.1016/j.actaastro.2013.07.024
    Date of publication: 2013-08-01
    Journal article

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    One of the biggest challenges of the exploration of the Moon is the survival of the crew and the lunar assets during the lunar night. The environmental conditions on the lunar surface and its cycle, with long periods of darkness, make any long mission in need of specific amounts of heat and electricity to be successful. We have analyzed two different systems to produce heat and electricity on the Moon's surface. The first system consists of Thermal Wadis, sources of thermal power that can be used to supply heat to protect the exploration systems from the extreme cold during periods of darkness. Previous results showed that Wadis can supply enough heat to keep lunar devices such as rovers above their minimum operating temperature (approximately 243 K). The second system studied here is the Thermal Energy Storage (TES), which is able to run a heat engine during the lunar night to produce electricity. When the Sun is shining on the Moon's surface, the system can run the engine directly using the solar power and simultaneously heat a thermal mass. This thermal mass is used as a high temperature source to run the heat engine during the night. We present analytical and numerical calculations for the determination of an appropriate thermal mass for the TES system.

  • Experimental analysis of the bubble-slug transition in a flow generated by a T-junction in a minichannel with air/water and air/ethanol mixtures in conditions relevant to microgravity

     Arias Calderón, Santiago; Gonzalez Cinca, Ricardo
    Chemical engineering science
    Vol. 91, p. 5-10
    DOI: 10.1016/j.ces.2012.12.036
    Date of publication: 2013-01-31
    Journal article

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    We present an experimental study on the bubble-slug flow pattern transition which takes place in two-phase flows in microgravity related conditions. Two different sets of experiments were performed on ground with air/water and air/ethanol mixtures in a minichannel with an internal diameter of 1 mm. We address questions regarding the existence of a critical void fraction for the bubble-slug transition to occur. Experimental data are compared to the drift-flux and Suratman models predictions. We obtain results on the extension of applicability of these models for different boundary conditions. (C) 2013 Elsevier Ltd. All rights reserved.

    We present an experimental study on the bubble–slug flow pattern transition which takes place in two-phase flows in microgravity related conditions. Two different sets of experiments were performed on ground with air/water and air/ethanol mixtures in a minichannel with an internal diameter of 1 mm. We address questions regarding the existence of a critical void fraction for the bubble–slug transition to occur. Experimental data are compared to the drift-flux and Suratman models predictions. We obtain results on the extension of applicability of these models for different boundary conditions.

  • Effects of momentum flux and separation distance on bubbly jet impingement in microgravity conditions

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Chemical engineering science
    Vol. 97, p. 272-281
    DOI: 10.1016/j.ces.2013.04.037
    Date of publication: 2013-04-27
    Journal article

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    The characteristics of two impinging bubble jets have been experimentally studied in microgravity conditions. The experimental setup, designed to be used in a drop tower, allows to change the gas and liquid ¿ow rates for the jet generation, and the separation distance between the jets. A slug ¿ow with millimetric air bubbles is created in a T-junction and injected through a nozzle in a water tank. The formation and dynamics of the generated bubble jets have been recorded by means of a high-speed camera. The effects of the momentum ¿ux and the separation distance on the two-phase ¿ow have been investigated. When jets do not interact, they show a conical shape with an opening angle which decreases from ¿ ¼631 to ¿ ¼121 as the momentum ¿ux is increased from J ¼1 g cm=s2 to J ¼88 g cm=s2. Bubble velocities in the direction of injection decrease fromvx ¼361 cm=s to vx ¼23 cm=s in the most extreme case, as the bubble center position reaches the impingement region. Interacting bubble jets form a cross-like shape as the jets evolve in time. Bubble mean diameter decreases fromd ¼1:7 cm to d ¼1:3 cm, as the momentum ¿ux increases from J ¼8 g cm=s2 to J ¼43 g cm=s2. Coalescence events, occurring mainly near the nozzles and in the impingement region, are responsible for the widening of the tail in the bubble size distribution. The global jet behavior and the individual bubble dynamics present several differences in microgravity compared to previous observations carried out on ground.

  • GESTION DE FLUJOS MULTIFASICOS Y DE ENERGIA PARA APLICACIONES EN EXPLORACION ESPACIAL

     Arias Calderón, Santiago; Suñol Galofre, Francesc Xavier; Garcia Sabate, Anna; Gonzalez Cinca, Ricardo
    Competitive project

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  • Like-doublet impinging liquid jets interactions in low gravity

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Workshop on Smart and Green Interfaces: Multiphase flows with/without phase change
    Presentation's date: 2013-10-04
    Presentation of work at congresses

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  • Interaction between an acoustic field and a boiling system

     Argelagós Palou, Anna; Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    Presentation's date: 2013-09-12
    Presentation of work at congresses

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  • Effects of gravity level on air bubbles rising in a quiescent liquid

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    p. 151-152
    Presentation's date: 2013-09-12
    Presentation of work at congresses

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  • Liquid jet injection in a low gravity environment

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    International Topical Team Workshop on Two-phase Flows for Ground and Space Applications
    Presentation's date: 2013-09-18
    Presentation of work at congresses

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  • Acoustic manipulation of rising bubbles at different gravity levels

     Garcia Sabate, Anna; Gonzalez Cinca, Ricardo
    Workshop Smart and Green Interfaces
    p. 35
    Presentation's date: 2013-03-21
    Presentation of work at congresses

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  • Bubble bouncing with a free surface in hypergravity conditions

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Workshop on Smart and Green Interfaces: Multiphase flows with/without phase change
    p. 124-125
    Presentation's date: 2013-03-21
    Presentation of work at congresses

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  • Research activities at the UPC-BarcelonaTech Microgravity Laboratory

     Gonzalez Cinca, Ricardo; Suñol Galofre, Francesc Xavier; Arias Calderón, Santiago; Garcia Sabate, Anna
    Workshop Smart and Green Interfaces
    p. 34
    Presentation's date: 2013-03-21
    Presentation of work at congresses

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  • The effects of hypergravity and acoustic fields on rising bubbles

     Garcia Sabate, Anna; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    Presentation's date: 2013-09-12
    Presentation of work at congresses

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  • Best poster award ISPS'11

     Gonzalez Cinca, Ricardo; Méndez, Num
    Award or recognition

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  • Numerical simulation of bubble generation in a T-juntion

     Arias Calderón, Santiago; Legendre, Dominique; Gonzalez Cinca, Ricardo
    Computers and fluids
    Vol. 56, p. 49-60
    DOI: 10.1016/j.compfluid.2011.11.013
    Date of publication: 2012-01-20
    Journal article

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  • Numerical study on the interaction between oscillating bubbles

     Garcia Sabate, Anna; Méndez, Num; Gonzalez Cinca, Ricardo
    Next-Generation Suborbital Researchers Conference
    Presentation's date: 2012-02-28
    Presentation of work at congresses

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  • Study of a system to generate electricity on the Moon's surface during the lunar night

     Torroba Moreno, Oscar; Climent Molina, Blai; Gonzalez Cinca, Ricardo; Ramachandran, Narayanan; Griffin, Michael D.
    Global Space Exploration Conference
    Presentation's date: 2012-05-23
    Presentation of work at congresses

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    One of the biggest challenges of the exploration of the Moon is the survival of the crew and the lunar assets during the lunar night. The environmental conditions on the lunar surface and its cycle, with long periods of darkness, make any long mission in need of specific amounts of heat and electricity to be successful. We have analyzed two different systems to produce heat and electricity on the Moon’s surface. The first system consists of the Thermal Wadis, sources of thermal power that can be used to supply heat to protect the exploration systems from the extreme cold during periods of darkness. Previous results showed that Wadis can supply enough heat to keep lunar devices such as rovers above their minimum operating temperature (approximately 243 K). The second system studied here is the Thermal Energy Storage (TES), which is able to run a heat engine during the lunar night to produce electricity. When the Sun is shining on the Moon’s surface, the system can run the engine directly using the solar power and simultaneously heat a thermal mass. This thermal mass is used as a high temperature source to run the heat engine during the night. We present analytical and numerical calculations for the determination of an appropriate thermal mass for the TES system.

  • Numerical simulation of bubbles behavior under acoustic fields

     Garcia Sabate, Anna; Méndez, Num; Gonzalez Cinca, Ricardo
    International Workshop on Bubble and Drop Interfaces
    p. 117
    Presentation's date: 2012-05-21
    Presentation of work at congresses

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  • Team presentation: UPC Barcelona

     Gonzalez Cinca, Ricardo
    Annual Workshop Meeting COST Action MP1106
    Presentation's date: 2012-09-13
    Presentation of work at congresses

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  • Effects of gravity level on the bouncing motion of an air bubble impacting with a free surface

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    International Workshop on Bubble and Drop Interfaces
    p. 37
    Presentation's date: 2012-05
    Presentation of work at congresses

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    Bubble and slug flows characteristic lengths in a microchannel  Open access

     Arias Calderón, Santiago; Gonzalez Cinca, Ricardo
    International Workshop on Bubble and Drop Interfaces
    p. 29
    Presentation's date: 2012-05-21
    Presentation of work at congresses

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  • ESA - SYT 2011 - Final Report

     Suñol Galofre, Francesc Xavier; Maldonado, Oscar; Vidal Arco, Eduardo; Garcia Sabate, Anna; Gonzalez Cinca, Ricardo
    Date: 2011-12
    Report

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  • Bubbly jet impingement in different liquids

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Microgravity science and technology
    Vol. 23, num. 2, p. 151-158
    DOI: 10.1007/s12217-010-9219-4
    Date of publication: 2011-02-16
    Journal article

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    The impingement of bubbly jets in distilled water and ethanol has been experimentally studied on ground. An experimental apparatus for the study of jet impingement on ground and inmicrogravity has been designed. The opposed-jet configuration with changeable orientation is used in order to study which is the better disposition to achieve an efficient mixing process. The impact angle between jets that can be changed from 0◦ (frontal collision) up to 90◦ (perpendicular collision). The impinging jets are introduced into a test tank full of liquid by means of two bubble injectors. The bubble generation method, insensitive to gravity level for low Bond numbers, is based on the creation of a slug flow inside a T-junction of capillary tubes of 0.7 mm of diameter. Bubble velocities at the injector outlet and generation frequencies can be controlled by changing gas and liquid flow rates. Individual bubble properties and coalescence events, as well as the whole jet structure are analyzed from the images recorded by a high speed camera. Bubble velocities are compared with the velocity field of a single-phase jet. Rate of coalescence between bubbles is found higher in ethanol than in water, creating a higher dispersion in bubble sizes.

  • Bubble and Droplet Flow Phenomena at Different Gravity Levels  Open access  awarded activity

     Suñol Galofre, Francesc Xavier
    Department of Applied Physics, Universitat Politècnica de Catalunya
    Theses

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    Two-phase flows are encountered in a wide range of applications both on-ground and in space. The dynamics of such flows in the absence of gravity is completely different from that in normal gravity due to the absence of buoyancy forces. A deeper understanding of the behavior of multiphase flows is essential in order to improve the operation of devices which require the use of two-phase systems. Analytical and experimental work is still needed for enhancing the control of two-phase flows, due to the theoretical complexity and the lack of experimental data for certain configurations. In this work, the behavior of two-phase flows has been studied experimentally in normal gravity and in microgravity conditions. In particular, the single-jet configuration has been investigated for bubbly jets and droplet jets. Dynamics of individual bubbles and droplets as well as the global structure of the jets has been considered. The opposed-jet configuration has been investigated for bubbly flows. Different separation between jets and orientation angles have been studied in normal gravity, and the obtained results have been compared to the microgravity case. A numerical model has been implemented to study single-phase jet impingement and opposed bubbly jets at different gravity levels. Good qualitative agreement between the simulations and the experiments has been obtained. The bubble bouncing process, prior to coalescence, after collision with a flat free surface has been also studied experimentally in normal gravity conditions. The results presented in this work will help to improve the general understanding of two-phase flows in normal gravity and in microgravity conditions, with general applications on mixing devices, environmental and propulsion systems.

  • An analysis of two-phase flows in conditions relevant to microgravity  Open access

     Arias Calderón, Santiago
    Universitat Politècnica de Catalunya
    Theses

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    Promising technological applications of two-phase flows in space have captured the increasing interest of the space sector, provoking a strong demand for more fundamental knowledge. Great efforts have been made in recent decades to study the behavior of two-phase flows in low-gravity environments, which is expected to be different than the behavior observed in the presence of gravitational forces. Nevertheless, many phenomena are still poorly understood. The development of any of these new technologies demands a better knowledge of two-phase flows. In this manuscript we address questions regarding the generation of gas-liquid flows and their behavior in conditions relevant for a microgravity environment. In particular, we focus on an air-water mixture formed in a capillary T-junction. To this end, an experimental setup has been designed to accurately control both gas and liquid flow rates. We performed a quantitative characterization on ground of the T-junction, whose operation is robust to changes in gravity level. Its main performance is the generation of bubbles at a regular frequency with small size dispersion. We obtained two working regimes of the T-junction and identified the crossover region between them. Bubble, slug, churn and annular flow regimes have been observed during the experiments and a flow pattern map has been plotted. We present an experimental study on the bubble-slug transition in microgravity-related conditions. In addition, we address questions regarding the existence of a critical void fraction in order for the bubble-slug transition to occur. The gas-liquid flow has been characterized by measuring the bubble generation frequency as well as the bubble and liquid slug sizes. Since bubble dynamics is also expected to be different in the absence of buoyancy, the bubble velocity has also been studied. The mean void fraction appears as one relevant parameter that allows for the prediction of frequency, bubble velocity, and lengths. We propose curves obtained empirically for the behavior of generation frequency, the bubble velocity and the lengths. The dependence of the frequency on the Strouhal dimensionless number has been analyzed. A numerical study of the formation of mini-bubbles in a 2D T-junction by means of the fluid dynamics numerical code JADIM is also presented. Simulations were carried out for different flow conditions, giving rise to results on the bubble generation frequency, bubble velocity, void fraction and characteristic lengths. Numerical results have been then compared with experimental data.

  • Droplet collisions after liquid jet breakup in microgravity conditions

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Journal of physics: conference series
    Vol. 327, num. 012026
    DOI: doi:10.1088/1742-6596/327/1/012026
    Date of publication: 2011
    Journal article

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    Numerical study of bubble dynamics with the Boundary Element Method  Open access

     Méndez, Num; Gonzalez Cinca, Ricardo
    Journal of physics: conference series
    DOI: doi:10.1088/1742-6596/327/1/012028
    Date of publication: 2011
    Journal article

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    A new Boundary Element Method software for simulating bubble dynamics is presented. This tool allows us to simulate a wide variety of scenarios, including external acoustic fields and multiple bubble interaction. We present results on the interaction between two oscillating bubbles in various configurations. Different sized bubbles under the effects of acoustic fields at different frequencies have been considered.

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    Numerical simulation of bubble generation in a T-junction  Open access

     Arias Calderón, Santiago; Legendre, Dominique; Gonzalez Cinca, Ricardo
    International Symposium on Physical Sciences in Space
    Presentation's date: 2011-07-13
    Presentation of work at congresses

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  • Liquid jet breakup and droplet dynamics in microgravity conditions

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    International Symposium on Physical Sciences in Space
    Presentation of work at congresses

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  • Impinging bubbly jets at different gravity levels

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    Presentation's date: 2011-09
    Presentation of work at congresses

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    Experimental setup for the study of the effects of vibrations on multiphase systems in suborbital flights  Open access

     Arias Calderón, Santiago; Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Next-Generation Suborbital Researchers Conference
    p. 58
    Presentation's date: 2011-03-01
    Presentation of work at congresses

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    We present an experimental setup for the study of the effects of controlled harmonic vibrations applied on multiphase systems in microgravity. This setup was recently launched onboard an ESA/DLR/SNSB Mini-Texus rocket with the aim to obtain data for the study of vibrations on two-phase flows with different liquids. We present preliminary results on the behaviour of bubbles under high acceleration variations. The experimental setup is ready to fly using the same test cell or a new one with different contents. We propose a new experiment consisting of the study of the interaction of granular media with different fluids under harmonic vibrations in microgravity.

  • Numerical study of the bubble dynamics at different gravity levels

     Méndez, Num; Gonzalez Cinca, Ricardo
    International Symposium of Physical Sciences in Space
    Presentation's date: 2011-07
    Presentation of work at congresses

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    Comparison of two methods for generating small bubbles with a T-junction in microgravity conditions  Open access

     Arias Calderón, Santiago; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    p. 121
    Presentation's date: 2011-09-08
    Presentation of work at congresses

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  • Study of acoustic levitation of particles in an ultrasonic resonator

     García-Sabaté, Anna; Hoyos, Mauricio; Castro, Angelica; Bazou, Despina; Gonzalez Cinca, Ricardo
    European Low Gravity Research Association Symposium
    Presentation's date: 2011-09
    Presentation of work at congresses

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    Characterization of the performance of a minibubble generator in conditions relevant to microgravity  Open access

     Arias Calderón, Santiago; Gonzalez Cinca, Ricardo; Ruiz, X; Ramirez de La Piscina Millan, Laureano; Casademunt Viader, Jaume
    Colloids and surfaces A: physicochemical and engineering aspects
    Vol. 365, num. 1-3, p. 52-55
    DOI: 10.1016/j.colsurfa.2010.03.004
    Date of publication: 2010-08-05
    Journal article

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    We perform a characterization of a recently reported minibubbles (bubbles with a diameter of the order of 10‐3 m) generator in microgravity related conditions. Generation of bubbles is based on the generation of a slug flow in a capillary T‐junction, whose operation is robust to changes in the gravity level. We address questions regarding the performance under different working regimes. In particular, we focus on the regimes found within a large range of gas and liquid injection flow rates. The injection performance is characterized by measuring bubble generation frequency. We propose curves obtained empirically for the behavior of generation frequency and crossover between regimes.

    Postprint (author’s final draft)

  • Opposed bubbly jets at different impact angles: jet structure and bubble properties

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    International journal of multiphase flow
    Vol. 36, num. 8, p. 682-689
    DOI: 10.1016/j.ijmultiphaseflow.2010.03.009
    Date of publication: 2010-08
    Journal article

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    The structure of two colliding water jets containing small gas bubbles is studied experimentally. The effects of the separation distance between jets, as well as the orientation angle, on the spatial distribution of bubbles have been considered. Results on the global structure of the final jet and bubble properties have been obtained using a high-speed video camera, and measurements of the positions of coalescence events are presented. Jets are introduced through inclined pipes (with a diameter of 0.7 mm) into a large water tank to avoid wall effects. Inclination angle has been changed from 0 to 45 with respect to the horizontal, resulting in a 0 up to 90 impact angle between jets. Generation of bubbles is controlled by a T-junction device where a regular slug-flow is created prior to injection. Bubble sizes have been measured, and a mean diameter of around 1 mm has been obtained using high values of the liquid flow rate. In the studied range of separation distances between the bubbly jets, a more homogeneous dispersion of bubbles is created as the distance between jets is decreased and the momentum flux of each jet is increased. Higher numbers of coalescences are observed when using smaller distance between jets, and the obtained measurements revealed that the number of bubble coalescence events is reduced significantly using high values of liquid flow rates.

  • Rise, bouncing and coalescence of bubbles impacting at a free surface

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Colloids and surfaces A: physicochemical and engineering aspects
    Vol. 365, num. 1-3, p. 36-42
    DOI: 10.1016/j.colsurfa.2010.01.032
    Date of publication: 2010-08-05
    Journal article

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  • ESA - DYT 2010 - Final Report

     Suñol Galofre, Francesc Xavier; Maldonado Diaz, Oscar; Garcia Sabate, Anna; Gonzalez Cinca, Ricardo
    Date: 2010-12
    Report

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  • Gestión de fluidos multifásicos en condiciones de baja gravedad

     Suñol Galofre, Francesc Xavier; Arias Calderón, Santiago; Gonzalez Cinca, Ricardo
    Competitive project

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    Experimental study of water droplet collisions in low gravity  Open access

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    Scientific Assembly of the Committee on Space Research
    Presentation's date: 2010-07
    Presentation of work at congresses

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    An experimental setup for the study of droplet collisions in a drop tower is presented.

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    Comparison of two methods for generating small bubbles in microgravity conditions  Open access

     Arias Calderón, Santiago; Garby, Romain; Gonzalez Cinca, Ricardo
    Scientific Assembly of the Committee on Space Research
    p. 1
    Presentation's date: 2010-07-20
    Presentation of work at congresses

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  • Design of an experiment for the study of bubble jet interactions in microgravity

     Suñol Galofre, Francesc Xavier; Maldonado, O; Pino, R; Gonzalez Cinca, Ricardo
    Microgravity science and technology
    Vol. 21, num. 1-2, p. 95-99
    DOI: 10.1007/s12217-008-9082-8
    Date of publication: 2009-01
    Journal article

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    Simulación: un curso innovador en los estudios de Aeronáutica  Open access

     Comellas Padro, Francesc de Paula; Gonzalez Cinca, Ricardo; Santamaria Barnadas, Eduard
    ReVisión
    Vol. 2, num. 2, p. 32-38
    Date of publication: 2009-12-01
    Journal article

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    Presentamos aquí una nueva metodología en la impartición de un curso de ciencias de la computación con énfasis particular en aspectos de dinámica de fluidos computacional (DFC) y las experiencias que se derivan de esta implementación. Las actividades principales que los estudiantes realizan en este curso son: el desarrollo de un proyecto inicial en la temática de ciencias de los materiales, la elaboración de un proyecto largo en DFC y una introducción al uso de un paquete de software específico de DFC. Los proyectos se realizan por grupos y consisten en la implementación (programación) de modelos matemáticos y una interfaz gráfica que permita la visualización de los resultados que se obtengan mediante la resolución numérica de los modelos considerados. La innovación en la asignatura se da en la utilización de técnicas de aprendizaje basado en proyectos o Project Based Learning y en el hecho que el curso es impartido de forma coordinada por varios profesores que provienen de áreas distintas. Otro aspecto novedoso lo constituye la oportunidad que presenta el curso para que los estudiantes redacten informes escritos, hagan presentaciones orales, utilicen el inglés y trabajen en un entorno Linux para el desarrollo de los proyectos.

  • Simulación: un curso innovador en los estudios de Aeronáutica

     Comellas Padro, Francesc de Paula; Gonzalez Cinca, Ricardo; Santamaria Barnadas, Eduard
    ReVisión
    Vol. 2, num. 2, p. 1-7
    Date of publication: 2009-12-01
    Journal article

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  • Experimental study of a microchannel bubble injector for microgravity applications

     Arias Calderón, Santiago; Ruiz, X; Casademunt Viader, Jaume; Ramirez de La Piscina Millan, Laureano; Gonzalez Cinca, Ricardo
    Microgravity science and technology
    Vol. 21, num. 1-2, p. 107-111
    DOI: 10.1007/s12217-008-9060-1
    Date of publication: 2009-01
    Journal article

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    Characterization of bubbly and slug flow regimes generated in a minichannel in microgravity conditions  Open access

     Arias Calderón, Santiago; Gonzalez Cinca, Ricardo
    International Workshop on Bubble and Drop Interfaces
    p. 1
    Presentation's date: 2009-09-24
    Presentation of work at congresses

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    We performed a characterization of the bubbly and slug flow regimes in minichannels in conditions relevant to microgravity. Two-phase flows were generated on ground by means of a T-junction device (1 mm i.d.), whose operation is independent to changes in gravity level [1]. Air and water were injected at several superficial velocities ranging from 0 up to 2 m/s. The generation and detachment of the minibubbles is provided by the liquid cross-flow (see figure). In nominal conditions small Bond and Weber numbers are achieved for the air/water mixture flow. Therefore, capillary forces dominate over buoyancy and inertial forces [2]. Laminar regime can also be assumed. Bubbly, slug, churn and annular flows were observed (see figure). The characterization consists in the analysis of the bubble and the unit cell lengths, the bubble velocity and the void fraction in both bubbly and slug flow regimes.

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    Bubbles in different liquids in microgravity and oscillating hipergravity environments  Open access

     Duarte, Laura; Maldonado, Oscar; Gallardo, Beatriz; Gonzalez Cinca, Ricardo
    ELGRA Biennial Symposium and General Assembly
    p. 324-325
    Presentation's date: 2009-09-03
    Presentation of work at congresses

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  • Bubbly jet impingement in different liquids

     Suñol Galofre, Francesc Xavier; Gonzalez Cinca, Ricardo
    European Conference for Aerospace Sciences
    p. 1-7
    Presentation's date: 2009-07
    Presentation of work at congresses

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    An experimental setup for the study of bubbly jets collision in microgravity has been designed. On ground preliminary results are presented in order to be compared with those obtained in a near future in low gravity conditions. The opposed-jet configuration is used with the objective to force the collision of two jets, with an impact angle between them that can be changed from 0º (frontal collision) up to 90º. The colliding jets are introduced into a test tank full of liquid by means of two bubble injectors. The bubble generation method is based on the creation of a slug flow inside a junction of capillary tubes of 0.7 mm of diameter. Bubble velocities at the injector outlet and generation frequencies can be controlled by changing the gas and liquid flow rates. We present results on the role played by the impact angle and bubble velocities on the structure of the final jet. A systematic study for different gas and liquid flow rates has been carried out in liquids with different values of surface tension.