Experimental study of the effects produced by the changes of the liquid and gas superficial velocities and the surface tension on the interfacial waves and the film thickness in annular concurrent upward vertical flows
Autor: | C. Berna, José-Luis Cuadros, Alberto Escrivá, J.L. Muñoz-Cobo, Yago Rivera |
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Rok vydání: | 2021 |
Předmět: |
Fluid Flow and Transfer Processes
Materials science Mechanical Engineering General Chemical Engineering ESTADISTICA E INVESTIGACION OPERATIVA Ripple Flow (psychology) Kapitza number Disturbance waves Aerospace Engineering Reynolds number Mechanics INGENIERIA NUCLEAR Ripple waves Annular flow Physics::Fluid Dynamics Surface tension symbols.namesake Amplitude Nuclear Energy and Engineering Surface-tension values symbols Interfacial waves Boundary value problem |
Zdroj: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia instname |
ISSN: | 0894-1777 |
DOI: | 10.1016/j.expthermflusci.2020.110224 |
Popis: | [EN] In this paper, we have performed an experimental study of the effect of changing the surface tension of the water in vertical annular concurrent two-phase flow (air + liquid) by adding small amounts of 1-butanol to the liquid phase. Adding small amounts of this chemical compound diminishes the surface tension of the water, while the dynamic viscosity remains practically unchanged. A set of experiments have been performed in the interval of surface tension values that ranges from 72 10(-3)N/m to 45 10(-3)N/m, and with different values of the superficial velocities of the gas and liquid flows. In this broad range of surface tensions and boundary condition values the average amplitude and frequency of the disturbance waves have been measured for each boundary condition and surface tension value. In addition, we also measured the mean amplitude of the ripple waves, the mean value of the unperturbed base thickness, and the average film thickness. Also, we have obtained a set of correlations expressing all these magnitudes in non-dimensional form in terms of the Reynolds number of the gas, the Reynolds number of the liquid and the Kapitza number. Finally, we have performed a brief discussion and comparison with the results of other authors This work was supported by the project EXMOTRANSIN ENE2016-79489-C2-1-P of the Spain National Research I+D Plan (MINECO). |
Databáze: | OpenAIRE |
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