GABRIEL ANGELO
26 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 26
Artigo IPEN-doc 28529 RANS-based CFD calculation for pressure drop and mass flow rate distribution in an MTR fuel assembly2021 - SCURO, N.L.; ANGELO, G.; ANGELO, E.; UMBEHAUN, P.E.; TORRES, W.M.; SANTOS, P.H.G.; FREIRE, L.O.; ANDRADE, D.A.This work presents a Reynolds-averaged Navier Stokes–based computational fluid dynamics methodology for the calculation of pressure drop and mass flow rate distribution in a material test reactor flat-plate-type standard fuel assembly (SFA) of the IEA-R1 Brazilian research reactor to predict future improvements in newer SFA designs. The results improve the understanding of the origin of fuel plate oxidation due to high temperatures, and consequently, due to the internal flow dynamics. All numerical analyses were performed with the ANSYS-CFX® commercial code. The observed results show that the movement pin decreases the central channel mass flow due to the length of the vortex at the inlet region. However, the outlet nozzle showed greater general influence in the flow dynamics. It should have a more gradual cross-section transition being away from the fuel plates or a squarer-shaped design to get a more homogeneous mass flow distribution. Optimizing both regions could lead to a better cooling condition. The validation of the IEA-R1 numerical methodology was made by comparing the McMaster University’s dummy model experiment with a numerical model that uses the same numerical methodology. The experimental data were obtained with laser Doppler velocimetry, and the comparison showed good agreement for both pressure drop and mass flow rate distribution using the Standard k-ω turbulence model.Artigo IPEN-doc 26385 Preliminary numerical analysis of the flow distribution in the core of a research reactor2019 - SCURO, NIKOLAS L.; ANGELO, GABRIEL; ANGELO, E.; TORRES, WALMIR M.; UMBEHAUN, PEDRO E.; ANDRADE, DELVONEI A. deThe thermal-hydraulic safety analysis of research reactors establishes the safety criteria to ensure the integrity of the fuel elements in the reactor core. It assures that all core components are being adequately cooled during operation. It is necessary to know if the average mass flow rate (and their standard deviation) among the fuel assemblies are enough to cool the power generated during operation. Once satisfied such condition, it allows the calculation of the maximum heat flux transferred from fuel assemblies to the coolant, and if the maximum cladding temperatures are below the limits set by the safety criteria. Among the objectives, this study presents a methodology for a preliminary three-dimensional numerical analysis of the flow distribution in the core of the IEA-R1 research reactor, under steady state condition. For this, the ANSYS-CFX® commercial code was used to analyze the flow dynamics in the core, and to visualize the velocity field. It was possible to conclude that a homogeneous flow distribution for all standard fuel assemblies were found, with 2.7% deviation from the average mass flow. What turned out to be negligible and can be assumed that there is a homogeneous distribution in the core. Complex structures were find in the computational domain. Once known the core flow dynamics, it allows future studies to determine whether the heat flux and temperature conditions abbeys thermal-hydraulic safety criteria.Artigo IPEN-doc 26394 A CFD analysis of blockage length on a partially blocked fuel rod2019 - SCURO, N.L.; UMBEHAUN, P.E.; ANGELO, E.; ANGELO, G.; ANDRADE, D.A.After a loss of coolant accident (LOCA), fuel rods may balloon. The swelling can partially block the flow channel, affecting the coolability during reflood phase. In order to analyze the influence of blockage length, using a radial block-age of 90%, varying just the blockage length, many steady state numerical simulations has been done using Ansys-CFX code to verify thermal-hydraulic properties according to different forced cooled conditions. Temperature peaks are observed on cladding, followed by a temperature drop. A 5x5 fuel assembly, with 9 centered ballooned fuel rod, flow redistribution inside channels can also be captured, indicating an overheating zone. Therefore, this study conclude, for the same boundary conditions, the longer the blockage length originated after LOCA events, the higher are the clad temperatures, indicating the possibility of overheat during transient conditions on reflood.Artigo IPEN-doc 24790 A CFD analysis of the flow dynamics of a directly-operated safety relief valve2018 - SCURO, N.L.; ANGELO, E.; ANGELO, G.; ANDRADE, D.A.A three-dimensional numerical study on steady state was designed for a safety relief valve using several openings and inlet pressures. The ANSYS-CFX (R) commercial code was used as a CFD tool to obtain several properties using dry saturated steam revised by IAPWS-IF97. Mass flow and discharge coefficient calculated from simulations are compared to the ASME 2011a Section 1 standard. The model presented constant behavior for opening lifts smaller than 12mm and is very reasonable when compared to the standard (ASME). In addition, the conventional procedure to design normal disc force assumes that all the fluid mechanical energy was converted into work; however, the CFD simulations showed that average normal disc force is about 19% lower than theoretical ASME force, which could prevent the valve oversizing. A numerical validation was conducted for a transonic air flow through a converging-diverging diffuser geometry to verify the solver's ability to capture the position and intensity of a shockwave: the results showed good agreement with the benchmark experiments.Resumo IPEN-doc 24614 A CFD numerical model for the flow distribution in a MTR fuel element2017 - ANDRADE, D.A.; ANGELOA, G.; ANGELO, E.; SANTOS, P.H.G.; OLIVEIRA, F.B.V.; TORRES, W.M.; UMBEHAUN, P.E.; SOUZA, J.A.B.; BELCHIOR JUNIOR, A.; SABUNDJIAN, G.; PRADO, A.C.Previously, an instrumented dummy fuel element (DMPV-01), with the same geometric characteristics of a MTR fuel element, was designed and constructed for pressure drop and flow distribution measurement experiments at the IEA-R1 reactor core. This dummy element was also used to measure the flow distribution among the rectangular flow channels formed by element fuel plates. A CFD numerical model was developed to complement the studies. This work presents the proposed CFD model as well as a comparison between numerical and experimental results of flow rate distribution among the internal flow channels. Numerical results show that the model reproduces the experiments very well and can be used for the studies as a more convenient and complementary tool.Resumo IPEN-doc 24581 CFD analysis of blockage length on a partially blocked fuel rod2017 - SCURO, N.L.; ANGELO, G.; ANGELO, E.; ANDRADE, D.A.In LOCA accidents, fuel rods may balloon by the increasing of pressure difference between fuel rod and core vessel. With the balloon effect, the swelling can partially block the flow channel, affecting the coolability during reflood phase. In order to analyze the influence of blockage length after LOCA events, many numerical simulations using Ansys-CFX code have been done in steady state condition, characterizing the final phase of reflood. Peaks of temperature are observed in the middle of the fuel rod, followed by a temperature drop. This effect is justified by the increasing of heat transfer coefficient, originated from the high turbulence effects. Therefore, this paper considers a radial blockage of 90%, varying just the blockage length. This study observed that, for the same boundary conditions, the longer the blockage length originated after LOCA events, the higher are the central temperatures in the fuel rod.Artigo IPEN-doc 21290 Numerical study of the influence of elements inside the wheelhouse on the passenger vehicle aerodynamic2015 - ANGELO, EDVALDO; ANGELO, GABRIEL; SANTOS, PEDRO H. di G.; ANDRADE, DELVONEI A. deArtigo IPEN-doc 19917 Comparison between two gas-cooled tru burner subcritical reactors: fusion-fission and ADS2011 - CARLUCCIO, T.; ROSSI, P.C.R.; ANGELO, G.; MAIORINO, J.R.; TALAMO, A.; GOHAR, Y.Artigo IPEN-doc 21041 Gamma stability and powder formation of UMo alloys2015 - OLIVEIRA, F.B.V.; ANDRADE, D.A.; ANGELO, E.; ANGELO, G.; BELCHIOR JUNIOR, A.; TORRES, W.M.; UMBEHAUN, P.E.Artigo IPEN-doc 20980 A CFD numerical model for the flow distribution in a MTR fuel element2015 - ANDRADE, DELVONEI A. de; ANGELO, GABRIEL; ANGELO, EDVALDO; SANTOS, PEDRO H. di G.; OLIVEIRA, FABIO B.V. de; TORRES, WALMIR M.; EMBEHAUN, PEDRO E.; SOUZA, JOSE A.B. de; BELCHIOR JUNIOR, ANTONIO; SABUNDJIAN, GAIANE; PRADO, ADELK de C.
- «
- 1 (current)
- 2
- 3
- »