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Fast Superfine Components and Sound Packets in Phenomena Induced by the Impact of a Drop on a Target Fluid in Quiescent Conditions

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Fluid Dynamics & Materials Processing 2020年第4期16卷 773-800页

作者： Yuli D.Chashechkin Ishlinsky Institute for Problems in mechanics RAS Moscow119526Russia

The structure of the flow and the acoustic signals generated by the impact of a freely falling drop of water with an underlying quiescent fluid have been investigated for droplets having diameter 0.5 cm and a contact ... 详细信息

关键词： Liquid drop impact fine flow waves sound energy

Study of the Thermal Characteristics of a Geomaterial:Case of SavèGranites in the Republic of Benin

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Journal of Environmental Science and Engineering(A) 2023年第4期12卷 151-161页

作者： Koffi Judicaël Agbelele Daniel Yemalin Agossou Kocouvi Agapi Houanou Bachir Kolade Adelakoun Ambelohoun Sakala Complice Decoursel Curtis Gérard Gbaguidi Aïsse Higher Normal School of Technical Education(ENSET) LokossaRepublic of Benin laboratory of Materials and Structures(LAMS) Verechaguine AK Higher SchoolCotonouRepublic of Benin laboratory of energetics and Applied mechanics(LEMA) EPAC UACAbomey-CalaviRepublic of Benin Civil Engineering Testing and Research laboratory(L2EGC) ENSTPAbomeyRepublic of Benin

This work focuses on the valorization of local *** rock that is granite,a material used in construction thanks to its mechanical resistance,is the subject of our *** granite of the commune of Savè,made it possible to appreciate the thermal behavior of this rock studied with a view to its use as a building *** this end,a thermal diffusivity measurement test was carried out on this ***,we made samples which were then connected to a data acquisition box via thermocouples.A Python script is used to ensure the collection of temperature values over *** this thermal diffusivity test carried out on the granite taken from the Savèbreasts,we obtained an average diffusivity a=5.84×10^(-6)m^(2)/*** a result,the thermal effusivity and the heat capacity of the material were determined having respectively the value 1,351.09 J/(K·m^(2)·s^(1/2))and 547,945.21 J/(m^(3)·K).These different results highlight a thermal characterization of Savègranites as a relevant material in the design and construction of an energy-efficient eco-housing.

关键词： Local materials thermal diffusivity thermal conductivity thermal effusivity heat capacity

Mixed Convection Heat Transfer for Nanofluids in a Lid-Driven Shallow Rectangular Cavity Uniformly Heated and Cooled from the Vertical Sides:The Opposing Case

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Journal of Electronics Cooling and Thermal Control 2013年第3期3卷 111-130页

作者： Hassan El Harfi Mohamed Naimi Mohamed Lamsaadi Abdelghani Raji Mohammed Hasnaoui Physics Department Faculty of Sciences and TechnologiesSultan Moulay Slimane UniversityLaboratory of Flows and Transfers Modelling(LAMET)Beni-MellalMorocco Polydisciplinary Faculty Sultan Moulay Slimane UniversityInterdisciplinary Laboratory of Research in Sciences and Technologies(LIRST)Beni-MellalMorocco Physics Department Faculty of Sciences SemlaliaCadi Ayyad UniversityLaboratory of Fluid Mechanics and Energetics(LMFE)MarrakechMorocco

An investigation on flow and heat transfer due to mixed convection, in a lid-driven rectangular cavity filled with Cu- water nanofluids and submitted to uniform heat flux along with its vertical short sides, has been conducted numerically by solving the full governing equations with the finite volume method and the SIMPLER algorithm. In the case of a slender enclosure, these equations are considerably reduced by using the parallel flow concept. Solutions, for the flow and temperature fields, and the heat transfer rate, have been obtained depending on the governing parameters, which are the Reynolds, the Richardson numbers and the solid volume fraction of nanoparticles. A perfect agreement has been found between the results of the two approaches for a wide range of the abovementioned parameters. It has been shown that at low and high Richardson numbers, the convection is ensured by lid and buoyancy-driven effects, respectively, whereas between these extremes, both mechanisms compete. Moreover, the addition of Cu-nanoparticles, into the pure water, has been seen enhancing and degrading heat transfer by lid and buoyancy-driven effects, respectively.

关键词： Component Nanofluids Mixed Convection Heat Transfer Lid-Driven Cavity Parallel Flow Assumption Finite Volume Method

Complete Coalescence, Partial Bounce and Rebound: Different Regimes Resulting from the Interaction of a Free Falling Drop with a Target Fluid

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Fluid Dynamics & Materials Processing 2020年第4期16卷 801-811页

作者： Yuli D.Chashechkin Andrey Y.Ilinykh Ishlinsky Institute for Problems in mechanics of the Russian Academy of Sciences Moscow119526Russia

The interaction of a falling drop(diluted aqueous solution of ink in various concentrations)with a target fluid(partially degassed tap water)has been tracked by means of high-resolution video recording and *** experimental setup has carefully been prepared in order to preserve the axial symmetry of initial *** regimes of interaction have been identified accordingly(depending on the drop velocity as controlled by the distance of fall):rapid droplet coalescence,rebound with the conservation of the drop volume and shape,and partial *** findings are recovered and confirmed,and enriched with heretofore unseen observations of complex partial *** extensive set of data is reported to support understanding of the observed dynamics and their repeatability and *** overall study has been carried out with the express intent to spur the future development of detailed mathematical models and numerical methods suited for this kind of problems.

关键词： Drop coalescence bounce spray transport of matter miscible fluids

Spreading of a Multicomponent Drop in Water: Solutions and Suspensions

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Fluid Dynamics & Materials Processing 2020年第4期16卷 723-735页

作者： Andrey Y.Ilinykh Ishlinsky Institute for Problems in mechanics of the Russian Academy of Sciences Moscow119526Russia

The distribution of material resulting from the impact of a freely falling drop with a target liquid has been studied by photo and video registration *** cases have been investigated by considering drops made of aqueous solutions(ink,salt,acid)and including fine solid particles(i.e.,suspensions).New features have been observed in terms of flow dynamics and thin components produced as a result of the impact(such as banded elements,ligaments,and vortices at the surface of the liquid).In particular,the characteristics of emerging netlike structures have been found to depend on the size of the suspension *** the case of acetic acid,a different patterning behavior has been obtained:sequences of concentric arcs are produced in that ***,linear scaling laws and the discrete nature of the distribution of the droplet material seem to be features common to all the cases considered.

关键词： Drop impact splashes ligaments material distribution

Oscillations of an Inviscid Encapsulated Drop

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Fluid Dynamics & Materials Processing 2020年第4期16卷 761-771页

作者： Aleksandr Shiryaev Ishlinsky Institute for Problems in mechanics of the Russian Academy of Sciences Moscow119526Russia

The problem relating to the small-amplitude free capillary oscillations of an encapsulated spherical drop is solved theoretically in the framework of asymptotic *** are supposed to be inviscid and *** formulas derived are presented for different parameters of the inner and outer liquids,including densities,thickness of the outer liquid layer,and the surface and interfacial tension *** frequencies of oscillation of the encapsulated drop are studied in relation to several“modes”which can effectively be determined in experiments by photo and video *** results are presented in terms of oscillation frequencies reported as a function of the mode number,the spherical layer thickness and the relation between the(surface and interfacial)tension *** is revealed that the influence of the liquids’parameters(and related variations)on the drop oscillation changes dramatically depending on whether oscillations are“in-phase”or“out-of-phase”.Frequencies for“in-phase”type oscillations can be correlated with linear functions of the shell thickness and the relative values of interfacial tension coefficient whereas the analogous dependencies for the“out-of-phase”type oscillation are essentially non-linear.

关键词： Encapsulated drop oscillation frequencies inviscid fluid

Influence of Fresh Water on Microbubble Generation in an Airlift Column Applied to Aquaculture: Extraction Capacity

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Open Journal of Applied Sciences 2022年第11期12卷 1809-1823页

作者： Djimako Bongo Nekoulnang Djetounako Clarisse Edith Kadjangaba Salif Gaye Jean-Yves Champagne Higher Normal School of Technology of Sarh Sarh Chad Paleontology Department National Research Center for Development of N’djamena N’djamena Chad Faculty of Sciences and Techniques University of Doba Doba Chad LME Materials and energetics laboratory University Institute of Technology Thiès Senegal laboratory of Fluid mechanics and Acoustics INSA-Lyon Lyon France

Bubble flows consist a liquid phase and a gaseous phase dispersed as bubbles. They occur in nature and in many industrial applications, such as oil transportation in pipelines and steam generators for power generation. Due to large difference in density between gas and liquid, the flottability force causes bubbles to rise, which in turn can generate overall motion and agitation in liquid. This use of gravity as a flow driver, which is specific to disperse phase systems, is used in process engineering (bubble columns and gasosiphon) to sparingly promote mixing and exchange between gas and liquid. In many applications, bubbles are used to agitate a liquid in order to promote mixing and transfers. This work is devoted to study of hydrodynamics of a bubble column. Experimentally, we have determined properties fluctuations of velocities inside the aquarium of rising homogeneous bubbles for different bubble sizes and vacuum rates. The interfacial area between gas and liquid phase is a crucial factor for mass transfer in bubble columns. The molecular exchange between a given volume of gas and water can be enhanced by formation of smaller bubbles, leading to a larger gas-liquid interface. This work presents the various physical phenomena that apply to bubbles, as well as associated dimensionless numbers. A state art of Micro-Bubble Generators (MBG) is then presented, presenting systems using various phenomena such as cavitation, electrolysis, or shear.

关键词： Vacuum Airlift Column MIBC Casein Turbidity Surfactant Coalescence

Thermodynamic and rate variational formulation of models for inhomogeneous gradient materials with microstructure and application to phase field modeling

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Acta Mechanica Sinica 2015年第2期31卷 162-172页

作者： Svyatoslav Gladkov Bob Svendsen Material mechanics RWTH Aachen Aachen Germany Microstructure Physics and Alloy Design Max-Planck-Institut fur Eisenforschung DusseldorfGermany

In this work,thermodynamic models for the energetics and kinetics of inhomogeneous gradient materials with microstructure are formulated in the context of continuum thermodynamics and material *** simplicity,attention is restricted to isothermal *** materials of interest here are characterized by（1） first- and secondorder gradients of the deformation field and（2） a kinematic microstructure field and its gradient（e.g.,in the sense of director,micromorphic or Cosserat microstructure）.Material inhomogeneity takes the form of multiple phases and chemical constituents,modeled here with the help of corresponding phase *** requirements together with the dissipation principle result in the reduced model field and constitutive *** cases of these include the wellknown Cahn-Hilliard and Ginzburg-Landau *** the last part of the work,initial boundary value problems for this class of materials are formulated with the help of rate variational methods.

关键词： Continuum thermodynamics Material inhomogeneity Conservative Non-conservative phase fields

Analysis of the Energy and Environmental Sustainability of a Built Space System: The Case of Patte d’Oie University Campus in Ouagadougou

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Energy and Power Engineering 2024年第5期16卷 197-215页

作者： Daouda Sawadogo Ousmane Coulibaly Xavier Chesneau Belkacem Zeghmati Laboratoire de Physique et de Chimie de l’ Environnement (LPCE) Department of Physics Universit&#233 Joseph KI-ZERBO Ouagadougou Burkina Faso Multidisciplinary Modeling and Simulation laboratory (LAMPS) Mechanics and Energetics Group (GME) Universit&#233 Perpignan Via Domitia Perpignan France

The aim of this study was to carry out a dynamic simulation of the energy and environmental performance of a built space system, with a view to assessing its energy and environmental class. The use of a simulation and modeling tool, supported by various methodological references, formed the basis of our approach. Adopting a systemic perspective, we described the structural and functional aspects of the systems making up built spaces, as well as the associated energy flows. Our approach was also based on a typology, taking into account typical days, structural and functional configurations at different scales and angles of observation. The analysis tool we developed in Java was applied to the built space system of the Patte d’Oie university campus in Ouagadougou. Annual electricity consumption was measured at 124387.34 kWh, closely aligned with the average annual electricity bill (125224.31 kWh), with a maximum relative deviation of 1%, followed by a carbon emission balance of 58337.66 kg eq CO2 per year. This validation confirmed the effectiveness of our tool. In addition, following the analysis of electricity consumption using our tool, the university campus was classified in energy class B and environmental class C. These results will be based on the emission factors of the energy mix of the West African Economic and Monetary Union (WAEMU) territory, with particular emphasis on Burkina Faso.

关键词： Energy Function Energy Class Carbon Footprint Built Space Consumption Item Systemic Approach Typological Approach