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  • The Effect of Swirl Intensity on the Flow Behavior and Combustion Characteristics of a Lean Propane-Air Flame
  • Abstract The effect of swirl number (Sn) on the flow behavior and combustion characteristics of a lean premixed propane Flame Ф = 0.5 in a swirl burner configuration was numerically verified in this study. Two-dimensional numerical simulations were performed using ANSYS-Fluent software. For turbulence closure, a standard K-ε turbulence model was applied. The turbulence-chemistry interaction scheme was modeled using the Finite Rate-Eddy Dissipation hybrid model (FR/EDM) with a reduced three-step reaction mechanism. The P1 radiation model was used for the flame radiation inside the combustion chamber. Four different swirl numbers were selected (0, 0.72, 1.05, and 1.4) corresponding to different angles…
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  • Numerical Study on the Resin Transfer Molding Curing Process for Thick Composites Materials
  • Abstract The successful manufacture of thick composites is challenging, since the highly exothermic nature of thermoset resins and limited temperature control make avoiding the onset of detrimental thermal gradients within the composite relatively difficult. This phenomenon is mainly caused by exothermic heat reactions. The so-called Michaud’s model has been largely used in the literature to reduce the gap between experience and simulation with regard to the effective prediction of the temperature cycle in these processes. In this work, another solution is proposed to simulate the curing process for thick composites, namely preheating the resin to activate the curing reaction before resin…
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  • Anomaly Detection on Textured Images with Convolutional Neural Network for Quality Control of Micrometric Woven Meshes
  • Abstract Industrial woven meshes are composed of metal material and are often used in construction, industrial and residential industries. The context of this work is defect detection in industrial fabrics in the quality control process. It is often performed with a manual method and could be quite tedious and time-consuming. We propose here a method to automatically detect defects in micrometric steel meshes using a Convolutional Neural Network. The database used for this work comes from the real problem of anomaly detection on micrometric woven meshes. This detection is performed through supervised classification with Convolutional Neural Network using a VGG19 architecture.…
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  • Simulation of Oil-Water Flow in a Shale Reservoir Using a Radial Basis Function
  • Abstract Due to the difficulties associated with preprocessing activities and poor grid convergence when simulating shale reservoirs in the context of traditional grid methods, in this study an innovative two-phase oil-water seepage model is elaborated. The modes is based on the radial basis meshless approach and is used to determine the pressure and water saturation in a sample reservoir. Two-dimensional examples demonstrate that, when compared to the finite difference method, the radial basis function method produces less errors and is more accurate in predicting daily oil production. The radial basis function and finite difference methods provide errors of 5.78 percent and…
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  • Determination of the Cement Sheath Interface and the Causes of Failure in the Completion Stage of Gas Wells
  • Abstract

    The bonding quality of the cement sheath interface decreases during well completion because of the change in the casing pressure. To explore the root cause of such phenomena, experiments on the mechanical properties and interface bonding strength of a cement sheath have been carried out taking the LS25-1 high-temperature and high-pressure (HTHP) gas field as an example. Moreover, a constitutive model of the cement sheath has been defined and verified both by means of a full-scale HTHP cement sheath sealing integrity evaluation experiment and three-dimensional finite element simulations. The results show that the low initial cementing surface strength is the…

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  • A Mathematical Model and a Method for the Calculation of the Downhole Pressure in Composite-Perforation Technological Processes
  • Abstract Using the conservation equations for mass, momentum and energy, a model is elaborated to describe the dynamics of high-energy gases in composite-perforation technological processes. The model includes a precise representation of the gunpowder combustion and related killing fluid displacement. Through numerical solution of such equations, the pressure distribution of the high-energy gas in fractures is obtained, and used to determine crack propagation. The accuracy of the model is verified by comparing the simulation results with actual measurements.
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  • Optimization of the Thermoelectric Performances of CoSbS Semiconductors Using the High-Pressure Fabrication Method
  • Abstract CoSbS-based compounds are good thermoelectric materials with low thermal conductivity and good electrical properties, which can effectively be used to improve the efficiency of many thermoelectric conversion processes. In order to improve their properties even more, in this study a series of experiments have been conducted in the frame of the traditional solid-phase synthesis and high-pressure method. It is shown that if the mass fluctuation and stress fluctuation in the considered CoSbS system increase, the scattering probability of phonons is enhanced and the lattice thermal conductivity of the material is reduced. Adding a small amount of Se can simultaneously optimize…
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  • Reinforcement of Clay Soils through Fracture Grouting
  • Abstract Fracture grouting is widely used for building foundation reinforcement, however the underpinning mechanisms are still not clear. Using numerical results about a single-hole fracture grouting process as a basis, a model composed of soil and grouting veins has been created to analyze the reinforcement mechanism. The influence weights of the grouting vein skeleton and compaction effect have been studied, thereby obtaining relevant information on the compressive modulus of the considered composite soil. The research results show that the compaction effect plays a leading role in the soil fracture grouting reinforcement. The grouting pressure, the hardened grouting vein modulus, and the…
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  • Thermomechanical Characterization of a Bio-Sourced Material Based on Clay and Alfa Fibers
  • Abstract Bio-based materials are of great interest owing to their abundance and the immense potential they display as an ideal alternative to widely used industrial construction materials (that directly and indirectly harm the environment). In this scope, an in-depth experimental study is presented here on clay-based materials aimed to enhance their properties through the addition of other bio-based components such as fibers, in the present case alfa fiber. The thermal conductivity and mechanical properties (compressive and flexural tensile strengths) of the composite clay-alfa material are analyzed with the percentage of alfa fiber in the matrix ranging from 0% to 4%. It…
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  • A Method for Identifying Channeling Paths in Low-Permeability Fractured Reservoirs
  • Abstract Often oilfield fractured horizontal wells produce water flowing in multiple directions. In this study, a method to identify such channeling paths is developed. The dual-medium model is based on the principle of inter-well connectivity and considers the flow characteristics and related channeling terms. The Lorentz curve is drawn to qualitatively discern the geological type of the low-permeability fractured reservoir and determine the channeling direction and size. The practical application of such an approach to a sample oilfield shows that it can accurately identify the channeling paths of the considered low-permeability fractured reservoir and predict production performances according to the inter-well…
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