This page has only limited features, please log in for full access.
Despite the increasing demand of Unmanned Aerial Vehicles (UAVs) for a wide range of civil applications, there are few methodologies for their initial sizing. Nowadays, classical methods, mainly developed for transport aircraft, have been adapted to UAVs. However, these tools are not always suitable because they do not fully adapt to the plethora of geometrical and propulsive configurations that the UAV sector represents. Therefore, this work provides series of correlations based on off-the-shelf components for the preliminary sizing of propulsion systems for UAVs. This study encompassed electric and fuel-powered propulsion systems, considering that they are the most used in the UAV industry and are the basis of novel architectures such as hybrid propulsion. For these systems, weight correlations were derived, and, depending on data availability, correlations regarding their geometry and energy consumption are also provided. Furthermore, a flowchart for the implementation of the correlations in the UAV design procedure and two practical examples are provided to highlight their usability. To summarize, the main contribution of this work is to provide parametric tools to size rapidly the propulsion system components, which can be embedded in a UAV design and optimization framework. This research complements other correlation studies for UAVs, where the initial sizing of the vehicle is discussed. The present correlations suit multiple UAV categories ranging from micro to Medium-Altitude-Long-Endurance (MALE) UAVs.
Victor Alulema; Esteban Valencia; Edgar Cando; Victor Hidalgo; Dario Rodriguez. Propulsion Sizing Correlations for Electrical and Fuel Powered Unmanned Aerial Vehicles. Aerospace 2021, 8, 171 .
AMA StyleVictor Alulema, Esteban Valencia, Edgar Cando, Victor Hidalgo, Dario Rodriguez. Propulsion Sizing Correlations for Electrical and Fuel Powered Unmanned Aerial Vehicles. Aerospace. 2021; 8 (7):171.
Chicago/Turabian StyleVictor Alulema; Esteban Valencia; Edgar Cando; Victor Hidalgo; Dario Rodriguez. 2021. "Propulsion Sizing Correlations for Electrical and Fuel Powered Unmanned Aerial Vehicles." Aerospace 8, no. 7: 171.
The geometry, volume, and mass properties (GVM) of lifting surfaces and wing box structures play an important role in aircraft design and optimization. Commercial Computer-Aided-Design packages can be employed to determine these features; however, they are difficult to embed in multidisciplinary frameworks because of their limited scripting capabilities and their black-box structure. In this context, the present work introduces an open-source, fully scriptable, high fidelity, and low computational demanding methodology to compute the volume and mass properties of lifting surfaces and wingbox structures using their three-dimensional geometric definition. NURBS modeling is employed to generate the 3-D geometry and derive the vertex representation of the lifting surface. The volume computation is based on the Divergence Theorem and employs a structured triangulation approach, tailored for lifting surfaces and their cross sections. The mass properties (i.e. center of mass and moments of inertia) are calculated as a system of mass particles. For this, a mass distribution model, based on the thickness and chord distribution throughout the lifting surface, has been elaborated. The methodology for volume computation and the mass distribution model has been validated analytically using a simple polytope that resembles to a lifting surface. The convergence and the robustness of the methodology has been evaluated for a straight tapered lifting surface. The results indicate a maximum error, compared with a commercial CAD software, of 0.3% and 0.5% for the volume and mass properties computation, respectively. In addition, to assess its suitability for complex lifting surfaces, the NASA Common Research Model aircraft (NASA-CRM) has been used as case of study. To summarize, the main contribution of this work lies on the development of an open-source and fully scriptable methodology, which can be easily implemented in any computational environment for aircraft design and optimization.
Esteban Valencia; Victor Alulema; Victor Hidalgo; Dario Rodriguez. A CAD-free methodology for volume and mass properties computation of 3-D lifting surfaces and wing-box structures. Aerospace Science and Technology 2020, 108, 106378 .
AMA StyleEsteban Valencia, Victor Alulema, Victor Hidalgo, Dario Rodriguez. A CAD-free methodology for volume and mass properties computation of 3-D lifting surfaces and wing-box structures. Aerospace Science and Technology. 2020; 108 ():106378.
Chicago/Turabian StyleEsteban Valencia; Victor Alulema; Victor Hidalgo; Dario Rodriguez. 2020. "A CAD-free methodology for volume and mass properties computation of 3-D lifting surfaces and wing-box structures." Aerospace Science and Technology 108, no. : 106378.
Esteban Valencia; Mathiu Berrazueta; Denisse Leines; Henry Lema; Dario A. Rodriguez; Victor Hidalgo. Correction: Aerodynamic design and testing of a Ram Air Turbine for Small Fixed-Wing UAVs. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleEsteban Valencia, Mathiu Berrazueta, Denisse Leines, Henry Lema, Dario A. Rodriguez, Victor Hidalgo. Correction: Aerodynamic design and testing of a Ram Air Turbine for Small Fixed-Wing UAVs. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleEsteban Valencia; Mathiu Berrazueta; Denisse Leines; Henry Lema; Dario A. Rodriguez; Victor Hidalgo. 2020. "Correction: Aerodynamic design and testing of a Ram Air Turbine for Small Fixed-Wing UAVs." AIAA Propulsion and Energy 2020 Forum , no. : 1.
Victor H. Alulema; Esteban Valencia; Danilo Pillajo; Monica Jacome; Juan Lopez; Byron Ayala. Degree of Deformation and Power Consumption of Compliant and Rigid-linked Mechanisms for Variable-Camber Morphing Wing UAVs. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleVictor H. Alulema, Esteban Valencia, Danilo Pillajo, Monica Jacome, Juan Lopez, Byron Ayala. Degree of Deformation and Power Consumption of Compliant and Rigid-linked Mechanisms for Variable-Camber Morphing Wing UAVs. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleVictor H. Alulema; Esteban Valencia; Danilo Pillajo; Monica Jacome; Juan Lopez; Byron Ayala. 2020. "Degree of Deformation and Power Consumption of Compliant and Rigid-linked Mechanisms for Variable-Camber Morphing Wing UAVs." AIAA Propulsion and Energy 2020 Forum , no. : 1.
Esteban Valencia; Darwin Jimenez; Victor H. Alulema; Ioannis Roumeliotis; Jimmy Montalvan; Marcelo Pozo; Edgar Cando. Modeling of a Series Hybrid Propulsion UAV Used for Monitoring in the Galapagos Islands. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleEsteban Valencia, Darwin Jimenez, Victor H. Alulema, Ioannis Roumeliotis, Jimmy Montalvan, Marcelo Pozo, Edgar Cando. Modeling of a Series Hybrid Propulsion UAV Used for Monitoring in the Galapagos Islands. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleEsteban Valencia; Darwin Jimenez; Victor H. Alulema; Ioannis Roumeliotis; Jimmy Montalvan; Marcelo Pozo; Edgar Cando. 2020. "Modeling of a Series Hybrid Propulsion UAV Used for Monitoring in the Galapagos Islands." AIAA Propulsion and Energy 2020 Forum , no. : 1.
The performance benefits of ingesting the boundary layer (BLI), in conjunction with the development of novel aircraft concepts - like the Blended Wing Body (BWB) - have been envisioned with the aim of increasing the aircraft propulsive efficiency whilst reducing the gas emissions in civil aviation. Preliminary studies have shown that BLI can also lessen considerably the takeoff gross weight (TOGW) and the fuel consumption. However, these benefits depends on the incoming flow quality since non-uniform and highly-distorted flows affect severally the performance of the turbomachinery. Moreover, since the BLI technology has not been formally considered in the design of medium UAVs, this work seeks to present a preliminary study regarding the potential benefits of integrating a BWBairframe with three electric ducted fans embedded into the fuselage. For this purpose, the fan thermodynamic behavior is modeled through parametric routines using a propulsor inner-control-volume to determine the effects on the aircraft performance. The flow characteristics, such as the velocity and pressure fields, are obtained from a high-fidelity numerical simulation (at each duct station) carried out in Open Foam. This study used five different inlet topologies to study the suitability of incorporating BLI to medium BWB airframe. Results showed that the low operating Mach and Reynolds numbers do not produce an important effect on the fan performance, since high inlet duct recovery factors are achieved. Furthermore, the three dimensional assessment enables to highlight that the spanwise pressure distribution of the main air frame is not affectted by the incorporation of semi embedded ducts.
Esteban Valencia; Miguel Ayala; Victor Hidalgo; Stalyn Simbaña; Victor H. Alulema; Dario A. Rodriguez; Edgar Cando. Aeropropulsive Evaluation of Boundary Layer Ingestion for Medium Electric-Powered UAVs. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleEsteban Valencia, Miguel Ayala, Victor Hidalgo, Stalyn Simbaña, Victor H. Alulema, Dario A. Rodriguez, Edgar Cando. Aeropropulsive Evaluation of Boundary Layer Ingestion for Medium Electric-Powered UAVs. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleEsteban Valencia; Miguel Ayala; Victor Hidalgo; Stalyn Simbaña; Victor H. Alulema; Dario A. Rodriguez; Edgar Cando. 2020. "Aeropropulsive Evaluation of Boundary Layer Ingestion for Medium Electric-Powered UAVs." AIAA Propulsion and Energy 2020 Forum , no. : 1.
Victor H. Alulema; Esteban Valencia; Eduardo Toapanta; Cesar Guailla; Micaela Pazmiño. Performance Assessment of a Variable-Span Morphing Wing Small UAV for High Altitude Surveillance Missions. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleVictor H. Alulema, Esteban Valencia, Eduardo Toapanta, Cesar Guailla, Micaela Pazmiño. Performance Assessment of a Variable-Span Morphing Wing Small UAV for High Altitude Surveillance Missions. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleVictor H. Alulema; Esteban Valencia; Eduardo Toapanta; Cesar Guailla; Micaela Pazmiño. 2020. "Performance Assessment of a Variable-Span Morphing Wing Small UAV for High Altitude Surveillance Missions." AIAA Propulsion and Energy 2020 Forum , no. : 1.
Esteban Valencia; David Changoluisa; Victor H. Alulema; Dario A. Rodriguez; Deyanira Valencia; Johanna Nandar; Juan Hernandez; Marcelo Pozo; Patricio Cruz; Edgar Cando. Power Management Strategies for Small Electric Fixed WingUAVs Employed in Natural Resources Mapping. AIAA Propulsion and Energy 2020 Forum 2020, 1 .
AMA StyleEsteban Valencia, David Changoluisa, Victor H. Alulema, Dario A. Rodriguez, Deyanira Valencia, Johanna Nandar, Juan Hernandez, Marcelo Pozo, Patricio Cruz, Edgar Cando. Power Management Strategies for Small Electric Fixed WingUAVs Employed in Natural Resources Mapping. AIAA Propulsion and Energy 2020 Forum. 2020; ():1.
Chicago/Turabian StyleEsteban Valencia; David Changoluisa; Victor H. Alulema; Dario A. Rodriguez; Deyanira Valencia; Johanna Nandar; Juan Hernandez; Marcelo Pozo; Patricio Cruz; Edgar Cando. 2020. "Power Management Strategies for Small Electric Fixed WingUAVs Employed in Natural Resources Mapping." AIAA Propulsion and Energy 2020 Forum , no. : 1.
In a hydraulic turbine, the search of a better energy exchange with the fluid has led to designs of runner blade of geometrical shapes so complex that they are considered as free-form surfaces. Since such blade characteristics are unable to be expressed by analytic functions, its complete and realistic geometrical reconstruction requires an excessive quantity of design parameters. This study proposes a coherent and robust full 3D blade numerical reconstruction methodology in which the geometrical definition of the blade is independent of its design parameters. A quantitative and qualitative fit evaluation shows that the blade surface reconstruction needs an important quantity of discrete data along the spanwise and streamwise direction to achieve a continuous and smooth definition. The results infer that the shape characteristics of damaged and worn blades without an original CAD model could be recovered, making this methodology attractive for industrial and optimization applications.
Giovanni Delgado; Sergio Galván; Francisco Dominguez-Mota; J. C. García; Esteban Valencia. Reconstruction methodology of a Francis runner blade using numerical tools. Journal of Mechanical Science and Technology 2020, 34, 1237 -1247.
AMA StyleGiovanni Delgado, Sergio Galván, Francisco Dominguez-Mota, J. C. García, Esteban Valencia. Reconstruction methodology of a Francis runner blade using numerical tools. Journal of Mechanical Science and Technology. 2020; 34 (3):1237-1247.
Chicago/Turabian StyleGiovanni Delgado; Sergio Galván; Francisco Dominguez-Mota; J. C. García; Esteban Valencia. 2020. "Reconstruction methodology of a Francis runner blade using numerical tools." Journal of Mechanical Science and Technology 34, no. 3: 1237-1247.
The performance benefits of directly ingesting the boundary layer (BLI) on air vehicles with distributed propulsion (DP) systems has been documented and explored extensively. However, numerous investigations have demonstrated that the increase of the flow distortion in the inlets of conventional propulsors can dramatically reduce the expected benefits. Hence, this work presents an alternative fan configuration to re-energize the boundary layer, and at the same time, to perform properly in a distorted and non-uniform flow-field. This conceptual design utilizes a two-dimension idealized fan and replaces the rotational movement with linear displacement, avoiding the undesired effects of circumferential distortion on the propulsor operation. A quasi two-dimensional model based on the Discretized Miller approach has been used to compare the proposed configuration with a conventional axial fan. From the results obtained, it is observed that the thermal performance of the fan is less affected for the proposed configuration and furthermore, intake pressure losses are ameliorated by the use of a single mailbox shape inlet. The performance assessment of the proposed configuration coupled on the N3-X aircraft shows benefits of 4% in fuel savings compared with current BLI turbo-machinery configurations. The main contribution of this study lies on the definition of a preliminary design for an alternative propulsor configuration able to deal with circumferential distortion.
Esteban Valencia; Victor Alulema; Dario Rodriguez; Panagiotis Laskaridis; Ioannis Roumeliotis. Novel fan configuration for distributed propulsion systems with boundary layer ingestion on an hybrid wing body airframe. Thermal Science and Engineering Progress 2020, 18, 100515 .
AMA StyleEsteban Valencia, Victor Alulema, Dario Rodriguez, Panagiotis Laskaridis, Ioannis Roumeliotis. Novel fan configuration for distributed propulsion systems with boundary layer ingestion on an hybrid wing body airframe. Thermal Science and Engineering Progress. 2020; 18 ():100515.
Chicago/Turabian StyleEsteban Valencia; Victor Alulema; Dario Rodriguez; Panagiotis Laskaridis; Ioannis Roumeliotis. 2020. "Novel fan configuration for distributed propulsion systems with boundary layer ingestion on an hybrid wing body airframe." Thermal Science and Engineering Progress 18, no. : 100515.
Wetlands in the Andean region have been altered and have been lost as a result of the agricultural frontier expansion and human activities. The disturbance of the paramo ecosystem by the destruction or alteration of the wetlands modifies the load and endowment of water to the hydrological systems, which provide water to main cities in the highlands. Therefore, the present work focuses on setting up the framework for wetland monitoring in the Andean paramo region using Unmanned Aerial Vehicles (UAVs). For this aim, the study was based on a mission profile using a fixed wing UAV incorporated with a RGB camera in one of the most documented wetlands in the Ecuadorian paramo region, Pugllohuma wetland. Furthermore, to assess the saturation of the wetland, field testing data has been collected to set the range values of saturation for the monitoring system. In the same way, a review regarding multispectral imagery for the assessment of water and vegetation indices is explored and highlighted for future work. This work is a first stage in the monitoring process and hence it aims to set a baseline study for the implementation of a more detailed methodology.
E A Valencia; K A Palma; I D Changoluisa; V H Hidalgo; P J Cruz; Carlos Cevallos; P J Ayala; D F Quisi; N G Jara. Wetland monitoring through the deployment of an autonomous aerial platform. IOP Conference Series: Earth and Environmental Science 2020, 432, 012002 .
AMA StyleE A Valencia, K A Palma, I D Changoluisa, V H Hidalgo, P J Cruz, Carlos Cevallos, P J Ayala, D F Quisi, N G Jara. Wetland monitoring through the deployment of an autonomous aerial platform. IOP Conference Series: Earth and Environmental Science. 2020; 432 (1):012002.
Chicago/Turabian StyleE A Valencia; K A Palma; I D Changoluisa; V H Hidalgo; P J Cruz; Carlos Cevallos; P J Ayala; D F Quisi; N G Jara. 2020. "Wetland monitoring through the deployment of an autonomous aerial platform." IOP Conference Series: Earth and Environmental Science 432, no. 1: 012002.
The inspection of wetlands in the Ecuadorian highlands has gained importance due to the environmental issues linked to the growth of human activities and the expansion of the agricultural and livestock frontiers. In this sense, unmanned aerial vehicles (UAVs) have been amply used in monitoring activities such as the supervision of threatened ecosystems, where cyclic measurements and high-resolution imagery are needed. However, the harsh operating conditions in the Andean highlands and sensitive ecosystem restrictions demand efficient propulsion configurations with low environmental impact. Electrical distributed propulsion (EDP) systems have surged as a forefront alternative since they offer benefits in both the propulsive and aerodynamic performance of fixed-wing UAVs. In this chapter, an EDP system is sized for a design point at the Andean operating conditions. Thereafter, two propulsion configurations were established based on off-the-shelf components, and their performance was characterized through analytical approaches. These results highlight the trends in power consumption and performance when the number of propulsors is increased. A significant contribution of this work is to exhibit important patterns in the performance of electric propulsion by using commercial components, and to set the operating limitations that can be further explored for analogous configurations in larger UAVs.
Esteban Valencia; Víctor Alulema; Darío Rodríguez. Wetland Monitoring Using Unmanned Aerial Vehicles with Electrical Distributed Propulsion Systems. Propulsion Systems 2019, 1 .
AMA StyleEsteban Valencia, Víctor Alulema, Darío Rodríguez. Wetland Monitoring Using Unmanned Aerial Vehicles with Electrical Distributed Propulsion Systems. Propulsion Systems. 2019; ():1.
Chicago/Turabian StyleEsteban Valencia; Víctor Alulema; Darío Rodríguez. 2019. "Wetland Monitoring Using Unmanned Aerial Vehicles with Electrical Distributed Propulsion Systems." Propulsion Systems , no. : 1.
The present paper focuses on the numerical simulation of unsteady cavitation around a NACA66 hydrofoil to improve the understanding of the cavitation effects on hydraulic machinery. For this aim, the Zwart–Gerber–Belamri cavitation model was updated and uploaded as a library file for OpenFOAM’s solvers using C++ language. Furthermore, the hybrid Reynold average Navier–Stokes (RANS)–large eddy simulation (LES) model k - ω SST scale adaptive simulation (SAS) was implemented as a turbulence model for the present study of scale adaptive simulation. For validation, numerical results were compared with experimental results obtained by Leroux at the Naval Academy Research Institute in France. In order to highlight the benefits in terms of computational consumption and reproduction of the phenomenon the k - ω SST SAS model was compared against implicit large eddy simulation (ILES). Results show that the cavitation evolution including the maximum vapor length, the detachment and the oscillation frequency were reproduced satisfactorily using k - ω SST SAS. Moreover, k - ω SST SAS results predicted a lower total vapor volume on time than ILES, which is related to observed pulses of pressure coefficient, C p , and those match fairly well with the experimental results. To summarize, the k - ω SST SAS model predicts with good accuracy unsteady cavitation behavior around hydrofoils and shows improved versatility over the ILES approach.
Víctor Hidalgo; Xavier Escaler; Esteban Valencia; Xiaoxing Peng; José Erazo; Diana Puga; Xianwu Luo. Scale-Adaptive Simulation of Unsteady Cavitation Around a Naca66 Hydrofoil. Applied Sciences 2019, 9, 3696 .
AMA StyleVíctor Hidalgo, Xavier Escaler, Esteban Valencia, Xiaoxing Peng, José Erazo, Diana Puga, Xianwu Luo. Scale-Adaptive Simulation of Unsteady Cavitation Around a Naca66 Hydrofoil. Applied Sciences. 2019; 9 (18):3696.
Chicago/Turabian StyleVíctor Hidalgo; Xavier Escaler; Esteban Valencia; Xiaoxing Peng; José Erazo; Diana Puga; Xianwu Luo. 2019. "Scale-Adaptive Simulation of Unsteady Cavitation Around a Naca66 Hydrofoil." Applied Sciences 9, no. 18: 3696.
Victor H. Alulema; Esteban A. Valencia; Edgar Cando; Dario Rodriguez. Preliminary sizing correlations for UAVs’ propulsion system. AIAA Propulsion and Energy 2019 Forum 2019, 1 .
AMA StyleVictor H. Alulema, Esteban A. Valencia, Edgar Cando, Dario Rodriguez. Preliminary sizing correlations for UAVs’ propulsion system. AIAA Propulsion and Energy 2019 Forum. 2019; ():1.
Chicago/Turabian StyleVictor H. Alulema; Esteban A. Valencia; Edgar Cando; Dario Rodriguez. 2019. "Preliminary sizing correlations for UAVs’ propulsion system." AIAA Propulsion and Energy 2019 Forum , no. : 1.
Daniel Vera-Hensiek; Esteban A. Valencia; Ericson Lopez; Wladimir Banda-Barragán. Modeling a propulsion system for the trajectory correction of weather balloons. AIAA Propulsion and Energy 2019 Forum 2019, 1 .
AMA StyleDaniel Vera-Hensiek, Esteban A. Valencia, Ericson Lopez, Wladimir Banda-Barragán. Modeling a propulsion system for the trajectory correction of weather balloons. AIAA Propulsion and Energy 2019 Forum. 2019; ():1.
Chicago/Turabian StyleDaniel Vera-Hensiek; Esteban A. Valencia; Ericson Lopez; Wladimir Banda-Barragán. 2019. "Modeling a propulsion system for the trajectory correction of weather balloons." AIAA Propulsion and Energy 2019 Forum , no. : 1.
Esteban A. Valencia; Miguel Oña; Dario Rodriguez; Alex Oña. Experimental Performance Assessment of an Electric UAV with an Alternative Distributed Propulsion Configuration Implemented for Wetland Monitoring. AIAA Propulsion and Energy 2019 Forum 2019, 1 .
AMA StyleEsteban A. Valencia, Miguel Oña, Dario Rodriguez, Alex Oña. Experimental Performance Assessment of an Electric UAV with an Alternative Distributed Propulsion Configuration Implemented for Wetland Monitoring. AIAA Propulsion and Energy 2019 Forum. 2019; ():1.
Chicago/Turabian StyleEsteban A. Valencia; Miguel Oña; Dario Rodriguez; Alex Oña. 2019. "Experimental Performance Assessment of an Electric UAV with an Alternative Distributed Propulsion Configuration Implemented for Wetland Monitoring." AIAA Propulsion and Energy 2019 Forum , no. : 1.
This study focuses on the development of a code to perform an appropriate analysis of nodular cast iron metallography. The platform developed was written in Python programming language and used the Open Source Computer Vision library (OpenCV) for the image processing. The OpenCV tool was applied in order to convert the color photo of the metallography to a grayscale image and hence enable the segmentation of the gray phases to calculate the percentage of carbon within the cast iron test specimen. The categorized microstructural phases were perlite, ferrite and graphite. For validation of the platform and the methodology, the obtained results were contrasted with the Architecture Street Furniture (ASF) ductile iron chart, from there the percentage of differences between the model developed and the baseline specimens were among 2 to 18% for ferrite, 0.4 to 2.2% for pearlite and 2.1 to 12.1% for graphite. Furthermore, the obtained nodularity from the study cases were compared using examples from the ASTM A247 norm and the differences were between 1.4 to 8.1%.
Victor Hidalgo; Victor Hugo Hidalgo Diaz; Anibal Silva; José Erazo; Esteban Valencia. Development of a Programming Code for Image Processing of Nodular Cast Iron. Advances in Intelligent Systems and Computing 2019, 327 -334.
AMA StyleVictor Hidalgo, Victor Hugo Hidalgo Diaz, Anibal Silva, José Erazo, Esteban Valencia. Development of a Programming Code for Image Processing of Nodular Cast Iron. Advances in Intelligent Systems and Computing. 2019; ():327-334.
Chicago/Turabian StyleVictor Hidalgo; Victor Hugo Hidalgo Diaz; Anibal Silva; José Erazo; Esteban Valencia. 2019. "Development of a Programming Code for Image Processing of Nodular Cast Iron." Advances in Intelligent Systems and Computing , no. : 327-334.
The present study deals with the numerical study of the cavitation micro–jet velocity and erosion on a plane–convex hydrofoil with semicylindrical obstacle, which induces a big cluster of cavities with a strong erosive power. The proposed model predicts micro-jet velocities based on energy conservation by assuming potential and kinetic energies at the start and the end of the cavity collapses. Homogeneous mixture flow, implicit LES and Zwart-Gerber-Belamri cavitation model have been used for the numerical simulation of the unsteady cavitating flow using OpenFOAM, whilst for the micro-jet estimation, Python language coupled with OpenFOAM's calculator have been used. Results clearly show that the implemented model captures adequately the phenomenon and enables to identify attacked areas. Outcomes agree reasonably with the experimental results obtained by Escaler at the High Speed Cavitation Tunnel of the École Polytechnique Fédérale de Lausanne (EPFL). Furthermore, the proposed model has been compared with Li's and Peters' ones for a better understating of the improvements.
V Hidalgo; X Luo; X Escaler; Esteban Valencia; P Cruz. Numerical simulation of the cavitation micro–jet velocity and erosion on a plane–convex hydrofoil with semicylindrical obstacle. IOP Conference Series: Earth and Environmental Science 2019, 240, 062018 .
AMA StyleV Hidalgo, X Luo, X Escaler, Esteban Valencia, P Cruz. Numerical simulation of the cavitation micro–jet velocity and erosion on a plane–convex hydrofoil with semicylindrical obstacle. IOP Conference Series: Earth and Environmental Science. 2019; 240 (6):062018.
Chicago/Turabian StyleV Hidalgo; X Luo; X Escaler; Esteban Valencia; P Cruz. 2019. "Numerical simulation of the cavitation micro–jet velocity and erosion on a plane–convex hydrofoil with semicylindrical obstacle." IOP Conference Series: Earth and Environmental Science 240, no. 6: 062018.
More than a half of the overall power capacity in Ecuador uniquely depends on hydroelectric power, thanks to its geographical position and large water resources. Most of them use Francis turbines, which present detriment in their lifetime due to the presence of high hardness sediments in the water reservoirs located close to the Andean mountains. In order to mitigate such effect, a structured methodology, which identifies design space variables and defines parameters that governs the phenomenon is developed. The optimization is carried out through genetic algorithms formulated to determine optimal geometrical features and hydraulic parameters based on Euler meanline turbomachinery equation. The objective function for the optimization study at this preliminary stage was erosion factor, whilst the decision variables used were: outlet diameter, acceleration flow, degree of reaction and percentage of curvature deviation from a linear of the blade angle distribution. The results obtained showed that the erosion factor can be reduced by 49 % and that the relative flow velocity at the exit was a key optimization parameter to decrease the runner erosion. This great improvement at preliminary design has been compared with other similar studies, showing a good enough prediction of erosion and the capturing of the phenomena. Furthermore, the important contribution of the present methodology is the development of a simple and versatile tool to define the design space for erosion phenomena and in this way improve the lifetime of the blade turbine runner and hence decreasing maintenance costs.
E A Valencia; E G Bone; J A Yánez; E H Cando; Sergio Galván; Victor Hidalgo. Parametric optimization to reduce erosion in a Francis turbine runner. IOP Conference Series: Earth and Environmental Science 2019, 240, 022041 .
AMA StyleE A Valencia, E G Bone, J A Yánez, E H Cando, Sergio Galván, Victor Hidalgo. Parametric optimization to reduce erosion in a Francis turbine runner. IOP Conference Series: Earth and Environmental Science. 2019; 240 (2):022041.
Chicago/Turabian StyleE A Valencia; E G Bone; J A Yánez; E H Cando; Sergio Galván; Victor Hidalgo. 2019. "Parametric optimization to reduce erosion in a Francis turbine runner." IOP Conference Series: Earth and Environmental Science 240, no. 2: 022041.
Edgar Cando; Renfang Huang; Esteban Valencia; Xianwu Luo. Sediment Erosion Prediction for a Francis Turbine Based on Liquid-Solid Flow Simulation Using Modified PANS. Proceedings of the 4th World Congress on Mechanical, Chemical, and Material Engineering 2018, 1 .
AMA StyleEdgar Cando, Renfang Huang, Esteban Valencia, Xianwu Luo. Sediment Erosion Prediction for a Francis Turbine Based on Liquid-Solid Flow Simulation Using Modified PANS. Proceedings of the 4th World Congress on Mechanical, Chemical, and Material Engineering. 2018; ():1.
Chicago/Turabian StyleEdgar Cando; Renfang Huang; Esteban Valencia; Xianwu Luo. 2018. "Sediment Erosion Prediction for a Francis Turbine Based on Liquid-Solid Flow Simulation Using Modified PANS." Proceedings of the 4th World Congress on Mechanical, Chemical, and Material Engineering , no. : 1.