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This article presents an approach to the problem of ceramic types adhesion, applying energy and matter balance to the established control volume (cyclone) with the use of mathematical formulas that are interrelated to develop mathematical calculations and establish a new mathematical model The first results are obtained by operating the energy balance considering the collision of particles, using the principle of conservation of energy, the first law of thermodynamics, in order to obtain information that allows describing the phenomena of thermoplasticity and creep, in the formation of adhesions, from a physicochemical and kinetic point of view, which will serve as the basis for understanding their effect. As a result, an energy value of 660 kJ / mol was obtained, sufficient energy to start the transformation of the solid particles to a state of thermo-flow that allows the adhesion phenomenon to be started. Keywords: Adhesion, energy balance, cyclones, elutriation, eutectoid, fayalite, thermoplasticity. References [1]O. Bustamante. “Dissipation of mechanical energy in the discharge of a hydrocyclone”. (Dyna, Ed.) The network of Scientific Journals of Latin America, the Caribbean, Spain, and Portugal, vol. 80 (181), Pages 136-143, 2013. [2]K.Petersen, P.Aldrich, and D.Van.,”Hydrocyclone underflow monitoring using image processing methods. Minerals Engineering”, pp. 301-315,1996. [3]M. Farghaly,” Controlled Wash Water Injection to the hydrocyclone underflow” [Ph.D. Thesis]. Erlangen, FAU, 2009. [4]M, Schneider, and T. Neesse. “Overflow-control system for a hydrocyclone battery. Int. J. Miner. Process". 74, pp. 339 – 343, 2004. [5]J.Bergström., “Flow field and fiber fractionation studies in hydro cyclones” [Ph.D. Thesis] Stockholm, Sweden, Royal Institute of Technology, 2006. [6]C, Liu, L. Wang, and Q. Lui., “Investigation of energy loss mechanisms in cyclone separators”. Chemical Engineering Technology 28, pp. 1182-1190, 2005. [7]O.Dam. & E.Jeffes.,.”Model for detailed assessment of chemical composition of reduced iron ores from single measurement”. Ironmaking and Steelmaking, 1987. [8]E. Ringdalen., “Softening and melting of SiO2 an important parameter for reactions with quartz in Si production” pp 43-44, 2016.

This work shows the computational simulation of the fluid dynamics of inductor discs (patent pending reception number MX/E/2021/002395) applied to vertical axis wind turbines (VAWT). These inductor discs have a unique and innovative design that can be classified as wind concentrators. The purpose of these devices is to increase wind velocity at the wind turbine entrance; this increase in velocity exponentially boosts the mechanical power of the turbine, according to Betz's theory, increasing the electrical energy production of the turbine and, at the same time, reducing its dimensions. The objective of this investigation is to carry out the fluid dynamic simulation (CFD) of two of the inductor disc geometries: an elliptical one and a truncated conical one, varying the entrance wind velocities of the VAWT from 3 m/s to 12 m/s. The proposed methodology consists of employing a CFD software (ANSYS) to model the two inductor disc geometries and extract them from a static control volume. Mesh this volume, establish boundary conditions, and vary wind velocities to carry out the fluid dynamic analysis. Finally, the obtained velocities are compared at different representative points of both geometries.

Abstract Fine sediment transport in rivers is important for catchment nutrient fluxes, global biogeochemical cycles, water quality and pollution in riverine, coastal and marine ecosystems. Monitoring of suspended sediment in rivers with current sensors is challenging and expensive and most monitoring setups are restricted to few single site measurements. To better understand the spatial heterogeneity of fine sediment sources and transport in river networks there is a need for new smart water turbidity sensing that is multi-site, accurate and affordable. In this work, we have created such a sensor, which detects scattered light from an LED source using two detectors in a control volume, and can be placed in a river. We compare several replicates of our sensor to different commercial turbidity probes in a mixing tank experiment using two sediment types over a wide range of typical concentrations observed in rivers. Our results show that we can achieve precise and reproducible turbidity measurements in the 0-4000 NTU or 0-16g/L range. Our sensor can also be used directly as a suspended sediment sensor and bypass an unnecessary calibration to Formazin. The developed turbidity sensor is much cheaper than existing options of comparable quality and is especially intended for distributed sensing across river networks.

A thermodynamic description of porous media must handle the size- and shape-dependence of media properties, in particular on the nano-scale. Such dependencies are typically due to the presence of immiscible phases, contact areas and contact lines. We propose a way to obtain average densities suitable for integration on the course-grained scale, by applying Hill’s thermodynamics of small systems to the subsystems of the medium. We argue that the average densities of the porous medium, when defined in a proper way, obey the Gibbs equation. All contributions are additive or weakly coupled. From the Gibbs equation and the balance equations, we then derive the entropy production in the standard way, for transport of multi-phase fluids in a non-deformable, porous medium exposed to differences in boundary pressures, temperatures, and chemical potentials. Linear relations between thermodynamic fluxes and forces follow for the control volume. Fluctuation-dissipation theorems are formulated for the first time, for the fluctuating contributions to fluxes in the porous medium. These give an added possibility for determination of the Onsager conductivity matrix for transport through porous media. Practical possibilities are discussed.

Heat transfer has always been one of the most important aspects of human life. So far, many sources have been reported on methods of increasing the heat transfer rate. Many of these methods focus on changes in equipment structure. These techniques can hardly cope with the growing demand for heat transfer and compression in equipment. Recent advances in nanoparticle production can be seen as a breakthrough in methods of increasing heat transfer. The purpose of this study is to numerically investigate the flow field and heat transfer of water-aluminium oxide nanofluid in a wavy channel. The channel consists of two parallel plates and is divided into three parts in the longitudinal direction. The beginning and end parts of the channel are insulated and the middle part is sinusoidal and receives a uniform heat flux. The nanofluid enters the channel at a uniform speed and temperature and exits it in an expanded manner. For numerical analyses, the finite difference method based on control volume and simple algorithm is used. In this research, Reynold’s effect was analysed. The results showed that by increasing the Reynolds number, the speed, temperature gradient and heat transfer rate was increased and the thickness of the thermal boundary layer was decreased. With increasing Reynolds number, the amount of heat transfer from the wall to the fluid and also the production of entropy increases. In the unsteady state, with increasing time and flow rate, the amount of heat transfer and total entropy and temperature gradient increase to reach the steady state.

Abstract Discharge from sluice gate flows is commonly calculated using the Torricelli outflow velocity, which is inaccurate and must be corrected by a discharge coefficient. Moreover, this approach commonly only considers the relative gate opening, without including the impact of 3D effects, scaling effects, different velocity profiles and friction forces. Aiming for a theoretical approach that can address all flow effects for sluice gate discharge calculations, the authors applied the momentum balance theory to this problem. First the control volume was introduced and parameterization equations for the pressure distributions and momentum coefficients at the control volume borders for both the standard and the inclined sluice gates were determined using CFD simulations. The results show good agreements with the discharge measurement results of frequently quoted experimental studies from other authors, demonstrating the potential of this approach. Also, one example of the impact of the 3D effect of various channels widths was investigated with the momentum balance theory.

This work is devoted to the study of the approximation, using two nonlinear numerical methods, of a  linear elliptic problem with measure data and heterogeneous anisotropic diffusion matrix. Both methods  show convergence properties to a continuous solution of the problem in a weak sense, through the change  of variable u = ψ(v), where ψ is a well chosen diffeomorphism between (−1, 1) and R, and v is valued  in (−1, 1). We first study a nonlinear finite element approximation on any simplicial grid. We prove the existence of a discrete solution, and, under standard regularity conditions, we prove its convergence to a  weak solution of the problem by applying Hölder and Sobolev inequalities. Some numerical results, in 2D  and 3D cases where the solution does not belong to H 1(Ω), show that this method can provide accurate  results. We then construct a numerical scheme which presents a convergence property to the entropy  weak solution of the problem in the case where the right-hand side belongs to L1 . This is achieved owing  to a nonlinear control volume finite element (CVFE) method, keeping the same nonlinear reformulation,  and adding an upstream weighting evaluation and a nonlinear p−Laplace vanishing stabilisation term.