3D CFD Modeling Investigation of Potential Vortex Formation at the Intakes of Caruachi Powerhouse

In this paper, the 3-D CFD simulation of the free-surface flow approaching the intakes of Caruachi Powerhouse is presented. The aim of the investigation is to determine whether or not vortex structures are likely to appear from the water surface through the intakes, as the result of the presence of cofferdams placed few meters upstream of the intakes. The presence of cofferdams was a note of concern with regard to the effects they might have on the turbine intakes once the hydroelectric central starts operating. In all the considered conditions, results did not show neither strong surface vortices in the proximities of the Power House intakes, nor air entrainment-entrapment towards the intakes, which reflects the safe operation of the turbines in the presence of the cofferdams. The latter added in decision taking on leaving the cofferdams submerged instead of removing them, which resulted in cost savings for the projec

3D CFD Modeling Investigation of Potential Vortex Formation at the Intakes of Caruachi Powerhouse

In this paper, the 3-D CFD simulation of the free-surface flow approaching the intakes of Caruachi Powerhouse is presented. The aim of the investigation is to determine whether or not vortex structures are likely to appear from the water surface through the intakes, as the result of the presence of cofferdams placed few meters upstream of the intakes. The presence of cofferdams was a note of concern with regard to the effects they might have on the turbine intakes once the hydroelectric central starts operating. In all the considered conditions, results did not show neither strong surface vortices in the proximities of the Power House intakes, nor air entrainment-entrapment towards the intakes, which reflects the safe operation of the turbines in the presence of the cofferdams. The latter added in decision taking on leaving the cofferdams submerged instead of removing them, which resulted in cost savings for the projec

Experimental study of a gas-loquid cylindrical cyclone separator performance

New data of the experimental performance of a Gas-Liquid Cylindrical Cyclone (GLCC) separator are presented. The data were collected using a 2 3/4” (0.07m) ID GLCC model working with an air-glycerin mixture. The inlet liquid flow rate, the inlet gas flow rate, the tangential liquid velocity inside the separator body and the gas carry under were measured for an operation regime without liquid carry over. The influence of the first three parameters over the gas carry under was established. Results show the separator efficiency is mainly affected by the inlet gas flow rate for the explored conditions with slug flow at the GLCC entrance

Experimental study of a gas-loquid cylindrical cyclone separator performance

New data of the experimental performance of a Gas-Liquid Cylindrical Cyclone (GLCC) separator are presented. The data were collected using a 2 3/4” (0.07m) ID GLCC model working with an air-glycerin mixture. The inlet liquid flow rate, the inlet gas flow rate, the tangential liquid velocity inside the separator body and the gas carry under were measured for an operation regime without liquid carry over. The influence of the first three parameters over the gas carry under was established. Results show the separator efficiency is mainly affected by the inlet gas flow rate for the explored conditions with slug flow at the GLCC entrance

Numerical simulation and experiments of the multiphase flow in a liquid-liquid cylindrical cyclone separator

A Liquid-Liquid Cylindrical Cyclone separator (LLCC) is a device used in the petroleum industry to separate the oil-water mixture obtained from the well. The use of this device has not been widespread due to the lack of tools for predicting its separation capability. This paper presents a numerical and experimental study of the fluid dynamic performance of this type of cylindrical cyclone separators. The use of numerical simulations would reduce the time and cost necessary to obtain information for predicting the behavior of the equipment. The objective of this study is to determine if CFD (Computational Fluid Dynamics) techniques are able to reproduce the behavior of a LLCC separator. The CFD software examined was ANSYS-CFX 5.6TM and numerical simulations were carried out using the dispersed model with oil as the dispersed phase. The oil and water mixture entering the separator is divided due to centrifugal and buoyancy forces in an upper (oil rich) exit and a bottom (water rich) exit. The separation capability is determined as the maximum amount of water removed from the mixture with the minimum amount of oil content in the water rich exit. The experiments were conducted in a transparent LLCC separator that allows the visualization of the mixture and the measurement of the oil content. Experiments were conducted for three variables: mixture velocity and water content at the entrance, and the split ratio. The split ratio is defined as the bottom exit flow rate divided by the water flow rate at the entrance. The results showed that CFD tools are able to reproduce the oil content obtained from the experiments for all analyzed conditions. Additionally, the mixture distribution images from numerical and experimental data showed good agreement. This study confirms the capacity of CFD tools for the multiphase flow analysis of LLCC separators

Numerical simulation and experiments of the multiphase flow in a liquid-liquid cylindrical cyclone separator

A Liquid-Liquid Cylindrical Cyclone separator (LLCC) is a device used in the petroleum industry to separate the oil-water mixture obtained from the well. The use of this device has not been widespread due to the lack of tools for predicting its separation capability. This paper presents a numerical and experimental study of the fluid dynamic performance of this type of cylindrical cyclone separators. The use of numerical simulations would reduce the time and cost necessary to obtain information for predicting the behavior of the equipment. The objective of this study is to determine if CFD (Computational Fluid Dynamics) techniques are able to reproduce the behavior of a LLCC separator. The CFD software examined was ANSYS-CFX 5.6TM and numerical simulations were carried out using the dispersed model with oil as the dispersed phase. The oil and water mixture entering the separator is divided due to centrifugal and buoyancy forces in an upper (oil rich) exit and a bottom (water rich) exit. The separation capability is determined as the maximum amount of water removed from the mixture with the minimum amount of oil content in the water rich exit. The experiments were conducted in a transparent LLCC separator that allows the visualization of the mixture and the measurement of the oil content. Experiments were conducted for three variables: mixture velocity and water content at the entrance, and the split ratio. The split ratio is defined as the bottom exit flow rate divided by the water flow rate at the entrance. The results showed that CFD tools are able to reproduce the oil content obtained from the experiments for all analyzed conditions. Additionally, the mixture distribution images from numerical and experimental data showed good agreement. This study confirms the capacity of CFD tools for the multiphase flow analysis of LLCC separators

Allosteric Modulators for GPCRs as a Therapeutic Alternative with High Potential in Drug Discovery

The superfamily of G protein-coupled receptors (GPCRs) consists of biological microprocessors that can activate multiple signaling pathways. Most GPCRs have an orthosteric pocket where the endogenous ligand(s) typically binds. Conversely, allosteric ligands bind to GPCRs at sites that are distinct from the orthosteric binding region and they modulate the response elicited by the endogenous ligand. Allosteric ligands can also switch the response of a GPCR after ligand binding to a unique signaling pathway, these ligands are termed biased allosteric modulators. Thus, the development of allosteric ligands opens new and multiple ways in which the signaling pathways of GPCRs can be manipulated for potential therapeutic benefit. Furthermore, the mechanisms by which allosteric ligands modulate the effects of endogenous ligands have provided new insights into the interactions between allosteric ligands and GPCRs. These new findings have a high potential to improve drug discovery and development and, therefore, creating the need for better screening methods for allosteric drugs to increase the chances of success in the development of allosteric modulators as lead clinical compounds

Cellulose dissolution and gelation in NaOH(aq) under controlled CO2 atmosphere : supramolecular structure and flow properties

We investigate the interplay between cellulose crystallization and aggregation with interfibrillar interactions, shear forces, and the local changes in the medium's acidity. The latter is affected by the CO2 chemisorbed from the surrounding atmosphere, which, combined with shear forces, explain cellulose gelation. Herein, rheology, nuclear magnetic resonance (NMR), small and wide-angle X-ray scattering (SAXS/WAXS), and focused ion beam scanning electron microscopy (FIB-SEM) are combined to unveil the fundamental factors that limit cellulose gelation and maximize its dissolution in NaOH(aq). The obtained solutions are then proposed for developing green and environmentally friendly cellulose-based materials.Peer reviewe