Mostrando ítems 1-20 de 40

2D Simulation of Two-Phase Flow for Water Jet Cutting Processes with OpenFOAM

Florez, Eder; Rojas Suárez, Jhan Piero; Espinel Blanco, Edwin (Italia, 2021)

Cold cutting processes are characterized to perform the kinetic energy needed to cut hard materials with little mechanical effort by means of the ultra-high flow pressure pumps, which produce water jets with a flow pressure ...
Acoustic emissions in the valuation of the combustion chamber pressure of an engine

Rojas Suárez, J P; Pabón León, J A; Orjuela Abril1, M S (2021-08-26)

Internal combustion engines demand advanced monitoring methodologies to promote efficient operation; particularly, the combustion pressure plays a central role in the overall performance, which promotes the utilization of ...
Analysis of the influence of textured surfaces and lubrication conditions on the tribological performance between the compression ring and cylinder liner

Pardo García, Carlos Eduardo; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (LubricantsSuiza, 2021-05-06)

The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication ...
Analysis of the ratio between the plasticity of clay and the expansion capacity by changes in humidity and temperature

caceres rubio, jose rafael; Pineda Rodriguez, José Ricardo; Rojas Suárez, Jhan Piero (Journal of Physics: Conference Series, 2021-09-21)

. Clay is a cohesive material that varies in volume due to changes in humidity and temperature. Its behavior is studied with physical and geotechnical characterization of the material. The experimental analysis of the ...
An application of physics: simply supported bridges made of post-tensioned concrete and structural steel beam

Márquez Peñaranda, J F; Pineda Rodríguez, J R; Rojas Suárez, J P (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

Bridges represent an important application of physics capable of solving real transportation problems. Knowledge of convenience of different mechanical solutions when analyzing and designing bridge is needed. For these ...
Comparison of lightening costs for reinforced concrete gantry

Prada Botia, Gaudy Carolina; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (Journal of Physics: Conference Series, 2019-11-19)

The selection of suitable materials for a construction defines the costs and characteristics that can contribute to the building, being of vital importance to make a correct choice. Lightening is an element to reduce costs ...
A Complete Prefeasibility Evaluation of On-Site Energy Generation System

Romero-Garcia, Gonzalo; Villada Castillo, Dora Clemencia; Rojas Suárez, Jhan Piero (International Journal of Energy Economics and PolicyTurquía, 2022-03-20)

The recent global concern to mitigate the ecological impact on energy production has promoted the search for alternatives that allow a better use of resources. In this panorama, the cogeneration process appears as a solution ...
Cost comparison between reinforced concrete moment resistant gantry system and reinforced concrete industrialized structural wall system

Rojas Suárez, Jhan Piero; Prada Botia, Gaudy Carolina; Orjuela Abril, Martha Sofia (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

The system of porticoes resistant to moments of reinforced concrete is a set of beams and columns connected by means of knots that allows the generation of adequate spaces with facility before changes by the same users, ...
Determination of expandability clay from San José de Cucuta metropolitan area, by varying calcination temperature and time

Sanchez Molina, Jorge; caceres rubio, jose rafael; Rojas Suárez, Jhan Piero (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

In this article, the volumetric change of the clay granules and sewage sludge (technological nutrient), San José de Cúcuta metropolitan area raw materials, when calcined at different temperatures and different burning times ...
Determination of expandability clay from San José de Cúcuta metropolitan area, by adding different percentages of sewage sludge

caceres rubio, jose rafael; Rojas Suárez, Jhan Piero; Sanchez Molina, Jorge (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

This article shows the research carried out on clay from the San José de Cúcuta metropolitan area, Colombia, to which was added several percentages of a wastewater sludge, which is called as a technological nutrient. The ...
Determination of the structural efficiency of short bridges according to their physical and economic characteristics

Pineda Rodríguez, J R; Rojas Suárez, J P; Prato Duarte, Fabian Alberto (Reino Unido, 2021-06-04)

Bridges are structures designed and built to overcome natural and artificial obstacles. The analysis and design of bridges is carried out following principles of physics applied to engineering. The aim is to estimate the ...
Development of a gravimetric fuel measurement system for the evaluation of engine performance physical parameters

Prada Botia, Gaudy Carolina; Rojas Suárez, J P; Orjuela Abril, M S (Reino Unido, 2021)

This paper presents the implementation and design features of a gravimetric-based fuel consumption system. The proposed system comprises a gravimetric balance with serial output, a fuel pump, and a control valve that are ...
Development of a numerical methodology for evaluating physical properties and technical specifications in thermoelectric devices

Prada Botia, Gaudy Carolina; Rojas Suárez, J P; Orjuela Abril, Martha Sofia (Reino Unido, 2021-06-04)

Typically, the performance evaluation of thermoelectric devices is done using experimental methods and analytical models, which require detailed information on the thermoelectric properties of the materials that make up ...
Development of a virtual bench for the analysis of the physical processes of internal combustion engines

Rojas Suárez, J P; Pabón León, J A; Orjuela Abril, M S (2021-08-27)

Currently, internal combustion engines face the challenge of reducing fuel consumption and reducing polluting emissions due to their significant impact on the environment. Therefore, it is necessary to use tools that allow ...
Development of an electro-pneumatic system for the practical training of pneumatic processes in the university environment

Rojas Suárez, Jhan Piero; PABON LEON, JHON ANTUNY; Orjuela Abril, Martha Sofia (Journal of Physics: Conference Series, 2021-06-11)

This article describes the implementation of an electro-pneumatic test bench, which allows the availability of a physical environment to promote learning. The aim of the paper is to create a tool that enables practical ...
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment

Pardo García, Carlos Eduardo; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (LubricantsSuiza, 2021-04-09)

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the ...
Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source

Rojas Suárez, Jhan Piero; Romero-Garcia , Gonzalo; Villada Castillo, Dora Clemencia (International Journal of Energy Economics and PolicyTurquía, 2022-01-19)

This article presents a comparison of energy generation using two methods of power production for different geographical locations. For this comparison, the HOMER software was used, which allows simulating generation systems ...
Evaluation of recycled asphalt pavement in Colombia

Yung Vargas, Yee Wan; Rondón-Quintana, Hugo Alexander; Cordoba Maquilon, Jorge Eliecer (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

Reclaimed asphalt pavements are obtained from existing pavements through recovery techniques and are used for new asphalt mixtures production with the inclusion of virgin aggregates and asphalt cement, constituting ...
Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

Rojas Suárez, J P; Pabón León, Jhon Antuny; Orjuela Abril, Martha Sofia (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development ...
Experimental and CFD Study of a Centrifugal Fan Performance Under ANSI/AMCA Standard

Rojas Suárez, Jhan Piero; Villada Castillo, Dora Clemencia; Flórez Solano, Eder (International Journal on Engineering ApplicationsItalia, 2021)

Centrifugal fans are widely employed for several technical applications in science and engineering due to their easy employment and practical use. Therefore, in this work, the centrifugal airfoil performance has been studied ...

Envíos recientes

2D Simulation of Two-Phase Flow for Water Jet Cutting Processes with OpenFOAM
...
Florez, Eder | 2021

Cold cutting processes are characterized to perform the kinetic energy needed to cut hard materials with little mechanical effort by means of the ultra-high flow pressure pumps, which produce water jets with a flow pressure value of around 90 ksi. These manufacturing processes may be studied considering the fluid mechanics' principles that describe the transport phenomena for inviscid, continuous, and incompressible laminar flows in order to obtain theoretical results approximated to the process conditions. In this sense, the numerical modeling techniques applied in the analysis of water jet cutting processes define an efficient solution of the processes due to the physical analysis of the partial differential equations, which quantify the abrasive flow particles into the system. Taking into account the above, this research proposes a numerical analysis of the physical phenomena through the two-phase flow simulation in steady state with OpenFOAM. Abrasive and liquid phases are quantified to study the turbulent values, which describe the water jet behavior under different working conditions. A 2D model has been computed and discretized, considering the nozzle features in order to visualize and predict the abrasive mixture and flow rejected by using a low computational effort. Therefore, this numerical approach has been validated with a mesh independency analysis developed to verify the relation between the numerical data and the finite number of nodes computed in order to discretize a computational domain and to solve analytically the system proposed until reaching a high approximation between the model and the experimental values obtained during the cutting process by means of abrasive flows.

LEER
Acoustic emissions in the valuation of the combustion chamber pressure of an engine
...
Rojas Suárez, J P | 2021-08-26

Internal combustion engines demand advanced monitoring methodologies to promote efficient operation; particularly, the combustion pressure plays a central role in the overall performance, which promotes the utilization of transducers that hinders. Therefore, the present study introduces an acoustic emission methodology that serves for indirect combustion pressure measurements. Accordingly, the compound methodology integrates the Hilbert transform and the complex cepstrum using neural networks to accomplish pressure signal reconstruction. Results demonstrated that the proposed methodology featured robust performance while estimating pressure signals as it mitigates the combined noise effect produced by variations in engine speed, engine load, and fuel type. Moreover, the reconstructed signal facilitated the determination of key performance parameters such as peak pressure, pressure timing, and effective mean pressure. Relative error amounted to less than 10%, which ratified the robustness of the indirect pressure measurements. In conclusion, acoustic signal techniques represent an adequate approach to estimate the combustion pressure at variable engine conditions.

LEER
Analysis of the influence of textured surfaces and lubrication conditions on the tribological performance between the compression ring and cylinder liner
...
Pardo García, Carlos Eduardo | 2021-05-06

The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication boundary conditions. The analysis is carried out by developing a numerical model, which involves hydrodynamic pressure, lubrication film thickness, textured surface, dynamic forces, and lubrication boundary conditions (starved lubrication and fully flooded lubrication). MATLAB® software (The MathWorks Inc., Natick, MA, USA) is used to solve the equations developed. The results show that the application of a textured surface on the cylinder liner allows obtaining a reduction of 20% and 5% in the asperity contact force and in the total friction force. Additionally, the textured surface allows for a 4% increase in MOFT. In this way, it is possible to reduce the power loss. The implementation of a boundary condition of fully flooded lubrication produces an overestimation in the total friction force due to the greater prominence of the lubrication film. Implementing a textured surface in the ring profile is an alternative way to reduce power loss. The results show that this alternative allows an 8% reduction in power loss.

LEER
Analysis of the ratio between the plasticity of clay and the expansion capacity by changes in humidity and temperature
...
caceres rubio, jose rafael | 2021-09-21

. Clay is a cohesive material that varies in volume due to changes in humidity and temperature. Its behavior is studied with physical and geotechnical characterization of the material. The experimental analysis of the expansiveness of clays is related to plasticity, which depends on the expansive minerals it contains. The objective is to analyze the relationship between the plasticity index and the expansion capacity due to changes in humidity and temperature; various types of clay from San José de Cúcuta, Colombia, were studied. Liquid limit and plastic limit were analyzed with which the plasticity index was determined. The test tube free expansion and calcination were carried out at 1000 °C to determine the volumetric change due to humidity and temperature, respectively. The clays with plasticity index of 10% - 20% presented expansion by humidity of 5% - 10% and by calcination of 0% - 10%, which indicates low expansion; while the clay with plasticity index of 20% - 40% presented expansion by moisture of 20% - 50% and by calcination of 25% - 50%, which indicates moderately high expansion. The results show that there is a relationship between plasticity index and the expansion capacity due to changes in humidity and temperature.

LEER
An application of physics: simply supported bridges made of post-tensioned concrete and structural steel beam
...
Márquez Peñaranda, J F | 2022-01-06

Bridges represent an important application of physics capable of solving real transportation problems. Knowledge of convenience of different mechanical solutions when analyzing and designing bridge is needed. For these reasons, this work is focused on the study of convenience of using two types of bridges. Simply supported short-medium span bridges (30 m to 45 m) are usually excessively long when choosing reinforced concrete solutions and usually short for other types of structures such as cable-stayed or cantilever bridges. The suitability of simply supported bridges leads to the need of studying their cost benefit ratios. This work studies the cost benefit ratio for post-tensioned concrete beams and structural steel girders in simply supported straight bridges. Eight models built of type I sections were used in both cases to analyze the bridges using a software based on the stiffness method. Span of each bridge was set to 30 m, 35 m, 40 m, and 45 m. The convenience of each type of bridge was done comparing the total and the cost per linear meter of each solution (post-tensioned and structural steel). Comparison was done using material consumption, labor, and construction processes costs only. Also, allowable vertical displacement given by current bridge design standards was verified

LEER
Comparison of lightening costs for reinforced concrete gantry
...
Prada Botia, Gaudy Carolina | 2019-11-19

The selection of suitable materials for a construction defines the costs and characteristics that can contribute to the building, being of vital importance to make a correct choice. Lightening is an element to reduce costs and optimize resources, adding a better index of resistance against earthquakes, being of vital importance the good choice of this: concrete, clay or EPS. In this investigation a comparison of costs and incidence of the three types of lighteners that are used in the construction of three levels houses with reinforced concrete portico based on the requirements of NSR-10 was made by means of statistical samples/data, graphs and tables of data analysis, on the quotations and information collected from different studies on lightening costs in structures.

LEER
A Complete Prefeasibility Evaluation of On-Site Energy Generation System
...
Romero-Garcia, Gonzalo | 2022-03-20

The recent global concern to mitigate the ecological impact on energy production has promoted the search for alternatives that allow a better use of resources. In this panorama, the cogeneration process appears as a solution seen with good eyes thanks to its great efficiency, which is why many institutions and companies have opted for the transition from the traditional system of energy production to cogeneration. This article develops the selection of the best alternative among different suppliers to implement a cogeneration system in an energy production plant, taking into account economic factors, selecting the one that represents the greatest profitability in the shortest time.

LEER
Cost comparison between reinforced concrete moment resistant gantry system and reinforced concrete industrialized structural wall system
...
Rojas Suárez, Jhan Piero | 2019-11-19

The system of porticoes resistant to moments of reinforced concrete is a set of beams and columns connected by means of knots that allows the generation of adequate spaces with facility before changes by the same users, whereas the industrialized system of structural walls of reinforced concrete, they are used for numerous, repetitive and of low price real estate, but they are completely immobile and in some occasions with problems of segregation and anthills. In this research work, a comparative study of the costs and budgets of the two proposed structural systems of the building was carried out in order to determine the structural system with the lowest costs and execution times, showing the results in explanatory graphs.

LEER
Determination of expandability clay from San José de Cucuta metropolitan area, by varying calcination temperature and time
...
Sanchez Molina, Jorge | 2019-11-19

In this article, the volumetric change of the clay granules and sewage sludge (technological nutrient), San José de Cúcuta metropolitan area raw materials, when calcined at different temperatures and different burning times is shown. The main objective is to evaluate out the work right conditions (temperature and time), for the production of light aggregates from expanded clay. The methodology that was followed consists of three phases: preparation and pelletization of clay mixtures and technological nutrient; application of heat treatment in a set of muffle furnaces; and application of statistical treatment with the help of Software R. One of the most important results is that the expansion of the clay is indifferent to the time it takes to cook the pellets, and that this property depends solely on the temperature of burning. The temperature that generates the greatest expansion is 1,200 Celsius degrees, using a set of muffle furnaces.

LEER
Determination of expandability clay from San José de Cúcuta metropolitan area, by adding different percentages of sewage sludge
...
caceres rubio, jose rafael | 2019-11-19

This article shows the research carried out on clay from the San José de Cúcuta metropolitan area, Colombia, to which was added several percentages of a wastewater sludge, which is called as a technological nutrient. The objective of the study is to find out with what percentage of technological nutrient the capacity of expansion of the granules is maximized. The methodology that was followed consists of four phases; preparation of raw materials; pelletizing of raw materials in granules of 5 to 10 millimeters; application of heat treatment in a rotary kiln at the pilot plant level; and application of descriptive statistics for analysis of results. It was determined that the mixture with a 20% of technological nutrient, produces the highest volumetric expansion ratio, with 1.56 times its initial size, while, when adding 30% of the nutrient the same expansion occurs when adding an 10% nutrient, which is 1.07 times the initial size of the particle.

LEER
Determination of the structural efficiency of short bridges according to their physical and economic characteristics
...
Pineda Rodríguez, J R | 2021-06-04

Bridges are structures designed and built to overcome natural and artificial obstacles. The analysis and design of bridges is carried out following principles of physics applied to engineering. The aim is to estimate the structural efficiency of short bridges according to their physical and economic characteristics through equations that measure the cost tendency, identifying which ones have the highest structural efficiency for a given length between supports. The design of short bridges was carried out by means of a mathematical modeling in a software based on finite elements. A comparative cost analysis was carried out for various types of short vehicular bridges designed with reinforced concrete decks supported by reinforced concrete beams; post-tensioned concrete beams; and structural steel beams. It was determined that the bridge with a reinforced concrete deck is the alternative with the best structural efficiency according to its physical and economic characteristics with spans of 12 meters and 18 meters. According to the estimated cost equations, it is concluded that, from 18.49 meters post-tensioned concrete bridges are the most efficient physically and economically. Structural steel bridges are the least structurally efficient for short bridges. Therefore, the construction of short vehicular bridges with structural steel is not feasible.

LEER
Development of a gravimetric fuel measurement system for the evaluation of engine performance physical parameters
...
Prada Botia, Gaudy Carolina | 2021

This paper presents the implementation and design features of a gravimetric-based fuel consumption system. The proposed system comprises a gravimetric balance with serial output, a fuel pump, and a control valve that are integrated into a complete engine test bench via Arduino UNO®. The study implements an instrumentation methodology to minimize measurement disturbance and error propagation, which represents a major concern in engine experimental testing. Moreover, an interactive virtual environment is developed to reinforce user interaction via LabView™. Results demonstrated that the proposed measurement system features robust and reliable operation while maintaining negligible disturbance and overall uncertainty ranging from 0.010-0.23 g/s. Additionally, it was evidenced that the measurement system allows the analysis of key parameters to evaluate engine performance. The study of the fuels blends shows that the ethanol content causes a 6.8% increase in brake specific fuel consumption and a 4% decrease in the brake thermal efficiency. Due to the low cost of the developed measurement system can be easily adapted to test bench laboratories to promote a better learning process and in industrial sectors for better energy management.

LEER
Development of a numerical methodology for evaluating physical properties and technical specifications in thermoelectric devices
...
Prada Botia, Gaudy Carolina | 2021-06-04

Typically, the performance evaluation of thermoelectric devices is done using experimental methods and analytical models, which require detailed information on the thermoelectric properties of the materials that make up the thermoelectric devices. However, this type of information is generally not available. Due to this situation, the present investigation seeks to develop a numerical methodology to determine the performance of thermoelectric devices, using technical reference specifications that are normally provided by the manufacturer, such as maximum current, maximum voltage, maximum temperature difference, and efficiency. The numerical model is made up of a series of equations based on thermoelectric phenomena, which generates a contribution in the area of physics. The results obtained are validated through experimental comparisons and the technical data of the thermoelectric devices. The comparison between the different results shows a maximum error of 5%. Therefore, the developed methodology is considered a robust tool for the realistic analysis of the performance of thermoelectric generators and thermoelectric coolers. The foregoing will allow massive use of this type of device in industrial applications and its commercial accessibility.

LEER
Development of a virtual bench for the analysis of the physical processes of internal combustion engines
...
Rojas Suárez, J P | 2021-08-27

Currently, internal combustion engines face the challenge of reducing fuel consumption and reducing polluting emissions due to their significant impact on the environment. Therefore, it is necessary to use tools that allow us to evaluate the operating characteristics of this type of thermal machines. In the present investigation, the development of a virtual bench was proposed for the analysis of the behavior and performance characteristics of an internal combustion engine for use as a learning tool in higher education students. From the results obtained, it could be demonstrated that the pressure curves of the combustion chamber and the rate of heat release obtained by means of the virtual bench presented a high concordance with the experimental records. The maximum deviation obtained was 5% and 15% for the pressure curve and the heat release rate. Comparing the performance parameters of the brake specific fuel consumption of the engine and energy efficiency, a maximum deviation of 2.96% was shown compared to the real engine. In general, the virtual development bank can describe the behavior of the engine, allowing the characterization of physical phenomena, as well as evaluating the effect of auxiliary technologies such as turbo-compression systems.

LEER
Development of an electro-pneumatic system for the practical training of pneumatic processes in the university environment
...
Rojas Suárez, Jhan Piero | 2021-06-11

This article describes the implementation of an electro-pneumatic test bench, which allows the availability of a physical environment to promote learning. The aim of the paper is to create a tool that enables practical training and research of pneumatic processes for university students in the field of engineering. The control and automation system of the test bench is made up of wired logic panels, timers, and programmable logic controllers, which are integrated into a control board configured at 24 V (direct current) to guarantee safety. Additionally, ergonomic principles were considered for the construction of the electro-pneumatic bench, thus favoring the accessibility and safety of the users. Based on national and international regulations, working pressure of 9 bar and an approximate pressure drop of 0.07 bar were defined. The construction of the test bench is considered an educational strategy to facilitate and accelerate the learning process of the students. Additionally, the development of the electro-pneumatic bench allowed the dynamic characterization of double-acting actuators by integrating experimental data and numerical models. This allowed the detailed analysis of the displacement, velocity, and acceleration variables in this type of actuator, which contributes to the physical study of pneumatic systems.

LEER
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment
...
Pardo García, Carlos Eduardo | 2021-04-09

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the bearing, cavitation effects, and surface roughness. For the numerical analysis, changes in the surface roughness of σ = 0.75 µm, σ = 1 µm, and σ = 1.25 µm are defined, and changes in the bearing load of 50%, 75%, and 100%. The results demonstrated that increasing the surface roughness intensifies the bearing wear, which represents 18% and 140% of the bearing clearance for the roughness of σ = 1 µm and σ = 1.25 µm, respectively. Additionally, the surface roughness causes a considerable increase in the bearing wear rate. The results described a maximum wear rate of 20 µm/s. In general, increasing the bearing load by 25% doubles the hydrodynamic pressure conditions increases friction force by 33%, and reduces lubrication film thickness by 12%. The analysis of the angle of deflection, φx and φy, shows that the moment and the degree of misalignment tend to increase significantly with the increase in the magnitude of the angle φy. Negative angles of deflection, φx, produce a greater increase in the degree of misalignment and the moment. This implies a greater chance of contact with the bearing surface. In conclusion, the proposed methodology serves as a reliable tool to simultaneously evaluate key parameters on the tribological behavior of bearings that further extend their endurance and minimize wear damage.

LEER
Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source
...
Rojas Suárez, Jhan Piero | 2022-01-19

This article presents a comparison of energy generation using two methods of power production for different geographical locations. For this comparison, the HOMER software was used, which allows simulating generation systems with different energy sources. For the development of these simulations it was necessary to collect three parameters in the locations to be analyzed, which were wind speed, solar radiation and temperature. The photovoltaic array system was simulated using from 10 to 200 units with a constant value of one wind turbine, while for the wind turbine system, 1 to 9 units were used together with a constant value of 100 photovoltaic arrays. For the photovoltaic system, there is no major difference in the net project cost, the renewable fraction and the annual carbon dioxide production when using a greater number of arrays, but an increase in energy production is observed, a greater effect is obtained by changing the location of the system, analyzing the wind system a greater number of turbines increases the energy production, but also increase the annual carbon dioxide production and project cost, there is no significant difference between locations for the project cost the other parameters are affected. By using an optimization algorithm in the systems, the best performance was obtained in Puerto Bolivar using 105 photovoltaic arrays of 1kW and 3 wind turbines of 1.5MW.

LEER
Evaluation of recycled asphalt pavement in Colombia
...
Yung Vargas, Yee Wan | 2022-01-06

Reclaimed asphalt pavements are obtained from existing pavements through recovery techniques and are used for new asphalt mixtures production with the inclusion of virgin aggregates and asphalt cement, constituting environmentally friendly mixtures at a lower total cost, by requiring fewer quantities of new materials. This research, unlike the studies found on the subject, focuses on the study of reclaimed asphalt pavement by analyzing its granulometric distribution and asphalt cement content. For this purpose, representative reclaimed asphalt pavement samples were taken from four Colombia cities, to verify their heterogeneity. The obtained reclaimed asphalt pavement was analyzed in the laboratory, to obtain the material granulometric distribution, through extraction and asphalt content tests, following Colombian regulations from the “Instituto Nacional de Vías”. The results show that the granulometry of all cities has a central tendency (average) that moves towards an upper limit in the 2 mm particles. When analyzing the granulometry separately of the four cities, it is observed that they present a different trend in their granulometry, which shows their heterogeneity. The asphalt cement content presented values between 4.0% and 5.0%.

LEER
Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section
...
Rojas Suárez, J P | 2022-01-06

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development of the study was carried out by means of numerical simulation to predict the behavior of the column against fire. The results of the numerical model are validated by comparing the temperature levels obtained through experimental tests. From the results obtained, it is shown that the increase in the contact area between the steel and the concrete reduces the average temperature of the column, which implies a greater resistance to fire. The fire resistance of the columns with the steel profile designs are between 3.4 - 3.6 times higher compared to the column only made of concrete, which is an indication of the excellent performance of the steel-reinforced concrete-filled steel tubular columns with circular crosssections columns. In general, the methodology proposed in this research allows the analysis of the thermal physical phenomena of the different columns used for the construction of buildings.

LEER
Experimental and CFD Study of a Centrifugal Fan Performance Under ANSI/AMCA Standard
...
Rojas Suárez, Jhan Piero | 2021

Centrifugal fans are widely employed for several technical applications in science and engineering due to their easy employment and practical use. Therefore, in this work, the centrifugal airfoil performance has been studied with experimental and computational fluid dynamics techniques in order to improve their energy efficiency influenced by the rotor-stator interaction. In this sense, this research proposes a study of the main components' aerodynamic performance in order to determine the optimal operating conditions for different geometries of the impeller blades. In order to validate the simulation results, an experimental study has been performed to configure the design of experiments with the data acquisition of velocity and pressure values of the air mass flow under different conditions in the test bench configured with the ANSI/AMCA 210-07 standard. The experimental procedure has been performed with 2500 rpm, like a constant value of the centrifugal fan's angular velocity. The experimentally acquired data have allowed validation and the definition of each treatment's response to establish a linear regression model in order to predict centrifugal fan performance under different working conditions. 5.4 kPa has been determined as the high static pressure value for different impeller blade configurations conformed by the blades' angle, number, and length features.

LEER