The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
M K Ramis - One of the best experts on this subject based on the ideXlab platform.
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effect of cladding on thermal behavior of Nuclear Fuel Element with non uniform heat generation
Progress in Nuclear Energy, 2019Co-Authors: R Abdul K Razak, Asif Afzal, A Mohammed D Samee, M K RamisAbstract:Abstract In Nuclear power reactors if the maximum temperature (2000ᵒC) of the Fuel Element like Uranium-dioxide increments and reaches 2865ᵒC then the Fuel Element melts down leading to heavy loss and damage. To maintain this maximum temperature well below the allowable limit the heat in the Fuel Element should be conducted and dissipated to the surrounding medium. In this article, the numerical prediction and comparison of thermal performance characteristics of a Nuclear Fuel Element with and without cladding (bare Fuel Element) having non-uniform energy generation in axial direction is studied in detail. Accordingly, the two-dimensional heat conduction equation having a cosine variation of heat generation term in the axial direction, along with appropriate boundary conditions is solved using second order accurate finite difference schemes. The results are presented for a wide range of parameters like Aspect Ratio Ar , Biot number, Bi , Conductivity ratio, Cr , Thickness ratio, Th , and total heat generation parameter, Qt in the form of transverse temperature profiles and axial temperature profiles. Effect of Cr and Th due to presence of cladding is thoroughly studied. Different range of parameters for which the temperature of the Fuel Element is within the maximum temperature range is obtained. Critical values of these parameters for which the temperature increments above maximum temperature is also investigated. From the detailed discussion of the results it is concluded that the maximum temperature attained in the Fuel Element without cladding (bare Fuel Element) is very much higher than that attained in Fuel Element with cladding. Also it is observed that for fixed values of Ar , Cr and Th , there exists a critical value of Qt and Bi beyond and below which maximum temperature in the Fuel Element exceeds its allowable limit.
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a comparative study between 1 d 2 d Nuclear Fuel Element cooled in a surrounding fluid medium
AIP Conference Proceedings, 2018Co-Authors: R Abdul K Razak, Asif Afzal, A Mohammed D Samee, M K RamisAbstract:This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a Nuclear Fuel Element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts the two dimensional model. It is also observed that for fixed values of Ar, Qt and Bi, there exists a critical value of Th beyond which maximum temperature in the Fuel Element exceeds its allowable limit.This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a Nuclear Fuel Element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts t...
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Numerical investigation of Prandtl number effect on heat transfer and fluid flow characteristics of a Nuclear Fuel Element
Nuclear Energy and Technology, 2017Co-Authors: R.k. Abdul Razak, Samee Mohammed, M K RamisAbstract:Abstract This paper investigates the heat transfer and fluid flow characteristics of liquid metal coolants (such as Sodium, Sodium potassium, Bismuth, Lead, and Lead–bismuth) flowing over a Nuclear Fuel Element having non-uniform internal energy generation numerically using finite difference method. The Full Navier Stokes Equations governing the flow were converted into stream function-Vorticity form and solved simultaneously along with energy equation using central finite difference scheme. For the two dimensional steady state heat conduction and Stream-Function Equation, the discretization was done in the form suitable to solve using ‘Line-by-Line Gauss-Seidel’ solution technique whereas the discretization of Vorticity transport and energy equations were done using Alternating Direction Implicit (ADI) scheme. After discretization the systems of equations were solved using ‘Thomas Algorithm’. The complete task was done by writing a computer code. The results were obtained in the form of variation of Maximum temperature in the Fuel Element (hot spots) and its location, mean coolant temperature at the exit .The parameters considered for the study were aspect ratio of Fuel Element, Ar, conduction-convection parameter Ncc, total energy generation parameter Qt, and flow Reynolds number ReH. The results obtained can be used to minimize the Maximum temperature in the Fuel Element (hot spots).
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conjugate conduction forced convection heat transfer analysis of a rectangular Nuclear Fuel Element with non uniform volumetric energy generation
International Journal of Heat and Mass Transfer, 2008Co-Authors: M K Ramis, G Jilani, S JahangeerAbstract:Abstract The main objective of this paper is to present a comparative study of uniform and non-uniform volumetric energy generation in a rectangular Nuclear Fuel Element washed by upward moving stream of liquid sodium. Employing finite difference schemes, the boundary layer equations governing the flow and thermal fields in the fluid domain are solved simultaneously with two-dimensional energy equation in the solid domain by satisfying the continuity of temperature and heat flux at the solid–fluid interface. Numerical results are presented for a wide range of aspect ratio, Ar, conduction–convection parameter, Ncc, total energy generation parameter, Qt, and flow Reynolds number, ReH. It is concluded that for the same total energy generation, a somewhat realistic non-uniform volumetric energy generation puts greater restriction on the thermal power generation as compared to the idealistic uniform volumetric energy generation. Further, it is found that despite the total energy generation being the same for two cases, the non-uniform volumetric energy generation within the Fuel Element results in considerably higher energy dissipation rate.
Yuan Yin - One of the best experts on this subject based on the ideXlab platform.
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design and evaluation of a high power density and high energy efficiency Fuel Element for space Nuclear reactors
Applied Thermal Engineering, 2021Co-Authors: Yangbin Deng, Bowen Qiu, Yuan YinAbstract:Abstract The enhancement of the power density and efficiency of space Nuclear reactors is of great value for space exploitation and exploration. Based on a TOPAZ-II space Nuclear reactor, a novel Fuel Element design was proposed for power density and energy efficiency improvements in this study. In addition to an external thermionic generator in the original Fuel design, a heat pipe thermoelectric generator (HPTEG) was implemented on the inside of the Fuel ring. This novel design allowed for a significant power density increase while lowering the Fuel temperature. Thermionic and thermoelectric simulation models were developed and then implemented in a thermo-mechanical analysis program for a space Nuclear Fuel Element. With this program, the thermo-mechanical, thermionic, and thermoelectric performances during long-term operation were investigated. The results indicated that the maximum allowable power density could be increased by 120% while substantially reducing the Fuel temperature in the new design. Compared with a thermionic generator, the HPTEG exhibited the characteristics of high output voltage and low current, which could reduce the joule dissipation and improve the energy utilization efficiency. Due to the high power density, the system energy conversion efficiency was increased from 9.2% to 13.4% and the system energy utilization efficiency was increased from 6.6% to 10.2%.
R Abdul K Razak - One of the best experts on this subject based on the ideXlab platform.
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effect of cladding on thermal behavior of Nuclear Fuel Element with non uniform heat generation
Progress in Nuclear Energy, 2019Co-Authors: R Abdul K Razak, Asif Afzal, A Mohammed D Samee, M K RamisAbstract:Abstract In Nuclear power reactors if the maximum temperature (2000ᵒC) of the Fuel Element like Uranium-dioxide increments and reaches 2865ᵒC then the Fuel Element melts down leading to heavy loss and damage. To maintain this maximum temperature well below the allowable limit the heat in the Fuel Element should be conducted and dissipated to the surrounding medium. In this article, the numerical prediction and comparison of thermal performance characteristics of a Nuclear Fuel Element with and without cladding (bare Fuel Element) having non-uniform energy generation in axial direction is studied in detail. Accordingly, the two-dimensional heat conduction equation having a cosine variation of heat generation term in the axial direction, along with appropriate boundary conditions is solved using second order accurate finite difference schemes. The results are presented for a wide range of parameters like Aspect Ratio Ar , Biot number, Bi , Conductivity ratio, Cr , Thickness ratio, Th , and total heat generation parameter, Qt in the form of transverse temperature profiles and axial temperature profiles. Effect of Cr and Th due to presence of cladding is thoroughly studied. Different range of parameters for which the temperature of the Fuel Element is within the maximum temperature range is obtained. Critical values of these parameters for which the temperature increments above maximum temperature is also investigated. From the detailed discussion of the results it is concluded that the maximum temperature attained in the Fuel Element without cladding (bare Fuel Element) is very much higher than that attained in Fuel Element with cladding. Also it is observed that for fixed values of Ar , Cr and Th , there exists a critical value of Qt and Bi beyond and below which maximum temperature in the Fuel Element exceeds its allowable limit.
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a comparative study between 1 d 2 d Nuclear Fuel Element cooled in a surrounding fluid medium
AIP Conference Proceedings, 2018Co-Authors: R Abdul K Razak, Asif Afzal, A Mohammed D Samee, M K RamisAbstract:This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a Nuclear Fuel Element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts the two dimensional model. It is also observed that for fixed values of Ar, Qt and Bi, there exists a critical value of Th beyond which maximum temperature in the Fuel Element exceeds its allowable limit.This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a Nuclear Fuel Element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts t...
Swarnendu Sen - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic analysis of a solid Nuclear Fuel Element surrounded by flow of coolant through a concentric annular channel
Progress in Nuclear Energy, 2015Co-Authors: Antarip Poddar, Rajeswar Chatterjee, Aranyak Chakravarty, Koushik Ghosh, Achintya Mukhopadhyay, Swarnendu SenAbstract:Abstract A continuous quest for efficient utilization of energy resources has motivated the researchers to search for optimal design and operating conditions during various energy conversion techniques. These conditions for such systems are often proposed by minimizing the destroyed exergy potential in course of the process. In the present paper a second law analysis is done for a Nuclear Fuel Element inside a concentric annular coolant passage. The entropy generation analysis has been carried out through a conjugate approach, with steady state temperature profiles within the Fuel Element and a thermodynamic approach within fluid. The effect of solid core heat generation and the temperature gradients inside solid core, Fuel - clad gap and cladding are considered as well along with the irreversibilities arising out of fluid flow under turbulent condition. The effect of Reynolds number, duty parameter, diameter ratio, Biot number, dimensionless heat flux and thermal conductivity ratios on overall entropy generation characteristics have been investigated and interpreted physically. The validation of the present calculations was confirmed by best-estimate thermal-hydraulic code RELAP. The new thermodynamic design methodology presented in this paper adheres to the safety limits in temperature. The present analysis can be extended for complex Fuel pellet arrangements in subchannel structures by an “equivalent annulus model”.
Bing Liu - One of the best experts on this subject based on the ideXlab platform.
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a novel coated particle design and fluidized bed chemical vapor deposition preparation method for Fuel Element identification in a Nuclear reactor
Particuology, 2017Co-Authors: Rongzheng Liu, Malin Liu, Youlin Shao, Xiaotong Chen, Bing LiuAbstract:Particle coating is an important method that can be used to expand particle-technology applications. Coated-particle design and preparation for Nuclear Fuel-Element trajectory tracing were focused on in this paper. Particles that contain Elemental cobalt were selected because of the characteristic gamma ray spectra of 60Co. A novel particle-structure design was proposed by coating particles that contain Elemental cobalt with a high-density silicon-carbide (SiC) layer. During the coating process with the high-density SiC layer, cobalt metal was formed and diffused towards the coating, so an inner SiC–CoxSi layer was designed and obtained by fluidized-bed chemical vapor deposition coupled with in-situ chemical reaction. The coating layers were studied by X-ray diffractometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy techniques. The chemical composition was also determined by inductively coupled plasma optical emission spectrometry. The novel particle design can reduce the formation of metallic cobalt and prevent cobalt diffusion in the coating process, which can maintain safety in a Nuclear reactor for an extended period. The experimental results also validated that coated particles maintain their structural integrity at extremely high temperatures (∼1950 °C), which meets the requirements of next-generation Nuclear reactors.
