<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1405-7743</journal-id>
<journal-title><![CDATA[Ingeniería, investigación y tecnología]]></journal-title>
<abbrev-journal-title><![CDATA[Ing. invest. y tecnol.]]></abbrev-journal-title>
<issn>1405-7743</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional Autónoma de México, Facultad de Ingeniería]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1405-77432020000100003</article-id>
<article-id pub-id-type="doi">10.22201/fi.25940732e.2020.21n1.003</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Evaluation of a vertical downward water film thickness using visualization and image recognition techniques]]></article-title>
<article-title xml:lang="es"><![CDATA[Evaluación del espesor de una película de agua descendente vertical con visualización y técnicas de reconocimiento de imágenes]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Larrainzar-Solís]]></surname>
<given-names><![CDATA[Edgar Fernando]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Moctezuma-Reyes]]></surname>
<given-names><![CDATA[José Javier]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Sánchez-Silva]]></surname>
<given-names><![CDATA[Florencio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Carvajal-Mariscal]]></surname>
<given-names><![CDATA[Ignacio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[García-Demedices]]></surname>
<given-names><![CDATA[Lino]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Instituto Politécnico Nacional ESIME UPALM]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Instituto Politécnico Nacional ESIME UPALM]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Instituto Politécnico Nacional ESIME UPALM]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af4">
<institution><![CDATA[,Instituto Politécnico Nacional ESIME UPALM]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<aff id="Af5">
<institution><![CDATA[,Instituto Politécnico Nacional ESIME UPALM]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Mexico</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>03</month>
<year>2020</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>03</month>
<year>2020</year>
</pub-date>
<volume>21</volume>
<numero>1</numero>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1405-77432020000100003&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1405-77432020000100003&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1405-77432020000100003&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract The present work is focused on the experimental study of a vertical downward annular flow to determine the thickness and stability of a falling film water flow. For this purpose, it was designed and implemented an experimental set up to generate the annular two-phase flow pattern, provided with an injection head with a special geometry to induce a liquid film inside a cylinder. Due to the small dimensions, the film was visualized using a pulsated laser to illuminate the region and the pictures were taken with a high-speed camera. This technique allowed the determination of the falling film thickness by means of an algorithm to recognize image contours. In some of the studied cases, a concurrent air flow was injected in the center of the cylinder in order to evaluate its influence on the interfacial hydrodynamics of the liquid film. Average film thickness were obtained for different Reynolds numbers in different axial observation points, and it was observed that the liquid film annular area and the shape of the header to inject the water, are important factors for the surface characteristic and thickness of the film, and its stability as well. The experimental results show that the standard deviation increases in proportion to the average film thickness, especially in the turbulent regime.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen El presente trabajo se centra en el estudio experimental de un flujo anular descendente vertical para determinar el espesor y la estabilidad de una película de agua descendente. Para este propósito, se diseñó e implementó una instalación experimental para generar el patrón de flujo anular de dos fases, provista de un cabezal de inyección con una geometría especial para inducir la formación de una película líquida dentro de un cilindro. Debido a sus pequeñas dimensiones la película se visualizó utilizando un láser pulsado para iluminar la región; igualmente, las imágenes se tomaron con una cámara de alta velocidad. Esta técnica permitió la determinación del espesor de la película descendente por medio de un algoritmo para reconocer los contornos de la imagen. En algunos de los casos estudiados, se inyectó un flujo de aire concurrente en el centro del cilindro para evaluar su influencia sobre la hidrodinámica interfacial de la película líquida. Se obtuvieron espesores promedio de la película para diferentes números de Reynolds en distintos puntos de observación axial, y se observó que el área anular de la película líquida y la forma del cabezal para inyectar el agua son factores importantes para la superficie característica y el espesor de la película y su estabilidad también. Los resultados experimentales muestran que la desviación estándar aumenta en proporción al espesor promedio de la película, especialmente en el régimen turbulento.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Hydrodynamics]]></kwd>
<kwd lng="en"><![CDATA[annular flow]]></kwd>
<kwd lng="en"><![CDATA[falling water film flow]]></kwd>
<kwd lng="en"><![CDATA[film thickness]]></kwd>
<kwd lng="en"><![CDATA[stability]]></kwd>
<kwd lng="en"><![CDATA[image recognition]]></kwd>
<kwd lng="es"><![CDATA[Hidrodinámica]]></kwd>
<kwd lng="es"><![CDATA[flujo anular]]></kwd>
<kwd lng="es"><![CDATA[película de agua descendente]]></kwd>
<kwd lng="es"><![CDATA[espesor de la película]]></kwd>
<kwd lng="es"><![CDATA[estabilidad]]></kwd>
<kwd lng="es"><![CDATA[reconocimiento de imágenes]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Adrian]]></surname>
<given-names><![CDATA[R.J.]]></given-names>
</name>
</person-group>
<source><![CDATA[Particle-imaging techniques for experimental fluid mechanics]]></source>
<year>2011</year>
<publisher-loc><![CDATA[U.S.A ]]></publisher-loc>
<publisher-name><![CDATA[Cambridge]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Andreussi]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
<name>
<surname><![CDATA[Asali]]></surname>
<given-names><![CDATA[J.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Hanratty]]></surname>
<given-names><![CDATA[T.J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Initiation of roll waves in gas liquid flows]]></article-title>
<source><![CDATA[American Institute of Chemical Engineers Journal]]></source>
<year>1985</year>
<volume>31</volume>
<page-range>119-26</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Asali]]></surname>
<given-names><![CDATA[J.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Hanratty]]></surname>
<given-names><![CDATA[T.J.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Ripples generated on a liquid film at high gas velocities]]></article-title>
<source><![CDATA[International Journal of Multiphase Flow]]></source>
<year>1993</year>
<volume>19</volume>
<page-range>229-43</page-range></nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Coulson]]></surname>
<given-names><![CDATA[J.M.]]></given-names>
</name>
</person-group>
<source><![CDATA[Ingeniería química, operaciones básicas]]></source>
<year>2003</year>
<publisher-loc><![CDATA[Barcelona ]]></publisher-loc>
<publisher-name><![CDATA[Reverté]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="book">
<collab>Dantec Dynamics</collab>
<source><![CDATA[Dantec Dynamics A/S]]></source>
<year>2016</year>
<publisher-name><![CDATA[Nova Instruments Company]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[González]]></surname>
<given-names><![CDATA[R.]]></given-names>
</name>
<name>
<surname><![CDATA[Wintz]]></surname>
<given-names><![CDATA[P.]]></given-names>
</name>
</person-group>
<source><![CDATA[Digital Image Processing]]></source>
<year>1987</year>
<publisher-loc><![CDATA[Tennessee ]]></publisher-loc>
<publisher-name><![CDATA[Pearson Prentice Hall]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hanratty]]></surname>
<given-names><![CDATA[T.J.]]></given-names>
</name>
<name>
<surname><![CDATA[Hershman]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Initiation of roll waves]]></article-title>
<source><![CDATA[American Institute of Chemical Engineers Journal]]></source>
<year>2018</year>
<volume>7</volume>
<page-range>488-97</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hewitt]]></surname>
<given-names><![CDATA[G.F.]]></given-names>
</name>
<name>
<surname><![CDATA[Govan]]></surname>
<given-names><![CDATA[A.H.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Phenomena and prediction in annular two-phase flow. Advances in gas-liquid flows]]></article-title>
<source><![CDATA[Winter Meeting]]></source>
<year>1990</year>
<volume>1</volume>
<page-range>41-56</page-range><publisher-name><![CDATA[American Society of Mechanical Engineers]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Levy]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
</person-group>
<source><![CDATA[Two-phase flow in complex systems]]></source>
<year>1999</year>
<publisher-loc><![CDATA[Canada ]]></publisher-loc>
<publisher-name><![CDATA[John Wiley &amp; Sons]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Libreros]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
</person-group>
<source><![CDATA[Análisis dinámico del comportamiento del flujo anular mediante el procesamiento de señales]]></source>
<year>2008</year>
<publisher-loc><![CDATA[México ]]></publisher-loc>
<publisher-name><![CDATA[Instituto Politécnico Nacional]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McKenna]]></surname>
<given-names><![CDATA[S.P.]]></given-names>
</name>
<name>
<surname><![CDATA[McGillis]]></surname>
<given-names><![CDATA[W.R.]]></given-names>
</name>
</person-group>
<source><![CDATA[Performance of digital image velocimetry processing techniques]]></source>
<year>2002</year>
<publisher-loc><![CDATA[Verlag ]]></publisher-loc>
<publisher-name><![CDATA[Springer]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Nusselt]]></surname>
<given-names><![CDATA[W.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Die oberaechen kondensateion des Waserdampfes]]></article-title>
<source><![CDATA[Vdiz e itschrift]]></source>
<year>1916</year>
<volume>67</volume>
<page-range>541-6</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Prasad]]></surname>
<given-names><![CDATA[A.K.]]></given-names>
</name>
</person-group>
<source><![CDATA[Particle image velocimetry]]></source>
<year>2000</year>
<publisher-loc><![CDATA[Delaware ]]></publisher-loc>
<publisher-name><![CDATA[Current Science]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="book">
<collab>Project SENER-CONACYT-147061</collab>
<source><![CDATA[Integral system for the generation of steam at the bottom of the well]]></source>
<year>2016</year>
<publisher-loc><![CDATA[México ]]></publisher-loc>
<publisher-name><![CDATA[Instituto Politécnico Nacional]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Swan-Bhagwat]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Afshin]]></surname>
<given-names><![CDATA[J.G.]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Study of flow patterns and void fraction in vertical downward Two-Phase flow]]></article-title>
<source><![CDATA[School of Mechanical and Aerospace Engineering]]></source>
<year>2018</year>
<volume>1</volume>
<page-range>255-480</page-range><publisher-name><![CDATA[Early Career Technical Conference]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="book">
<collab>Teknica Petroleum Services Ltd</collab>
<source><![CDATA[Mathworks]]></source>
<year>2001</year>
<publisher-loc><![CDATA[Canada ]]></publisher-loc>
<publisher-name><![CDATA[Teknica. The MathWorks, Inc.]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[L.]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[Y.]]></given-names>
</name>
<name>
<surname><![CDATA[Guo]]></surname>
<given-names><![CDATA[Q.]]></given-names>
</name>
</person-group>
<source><![CDATA[Flow characteristics of vertical falling film in scrubbing-cooling pipe. Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education]]></source>
<year>2013</year>
<numero>64</numero>
<issue>64</issue>
<publisher-loc><![CDATA[Shanghai ]]></publisher-loc>
<publisher-name><![CDATA[De East China University of Science and Technology]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zhu]]></surname>
<given-names><![CDATA[Z.F.]]></given-names>
</name>
</person-group>
<source><![CDATA[A study of the interfacial features of gas-liquid annular two-phase flow]]></source>
<year>2004</year>
<publisher-loc><![CDATA[Canada ]]></publisher-loc>
<publisher-name><![CDATA[University of Saskatchewan]]></publisher-name>
</nlm-citation>
</ref>
</ref-list>
</back>
</article>
