Flux Gradient Research Articles

Dynamics of ternary-hybrid nanofluid subject to magnetic flux density and heat source or sink on a convectively heated surface

The size and intensity of the system of delocalized electrons are reflected in the form of the induced magnetic field. Even though this also affects nearby molecules, nothing is known on the significance of stagnant water conveying silver Ag, aluminum oxide Al2O3, and aluminum Al nanoparticles of different shapes on a horizontal surface experiencing convectively heating as applicable in the industry. Relevant similarity transformations were adopted to non-dimenzionalized the governing equations and solved numerically using the 3-stage Lobatto IIIa integration formula for a finite difference (MATLAB package bvp4c). Based on the analysis of the new results, it is worth concluding that either in the case of heat source or heat sink, an increment in the convective heating of the wall is a factor capable to boost the temperature distribution. Increasing effects of an inclined magnetic field are capable to cause the distance between the turning points of shear stress and that of the gradient of magnetic flux density to be located at the middle of the domain.

The Two-step Forbush Decrease: A Tale of Two Substructures Modulating Galactic Cosmic Rays within Coronal Mass Ejections

Abstract Interplanetary coronal mass ejections (ICMEs) are known to modify the structure of the solar wind as well as interact with the space environment of planetary systems. Their large magnetic structures have been shown to interact with galactic cosmic rays (GCRs), leading to the Forbush decrease (FD) phenomenon. We revisit in the present article the 17 yr of Advanced Composition Explorer spacecraft ICME detection along with two neutron monitors (McMurdo and Oulu) with a superposed epoch analysis to further analyze the role of the magnetic ejecta in driving FDs. We investigate in the following the role of the sheath and the magnetic ejecta in driving FDs, and we further show that for ICMEs without a sheath, a magnetic ejecta only is able to drive significant FDs of comparable intensities. Furthermore, a comparison of samples with and without a sheath with similar speed profiles enable us to show that the magnetic field intensity, rather than its fluctuations, is the main driver for the FD. Finally, the recovery phase of the FD for isolated magnetic ejecta shows an anisotropy in the level of the GCRs. We relate this finding at 1 au to the gradient of the GCR flux found at different heliospheric distances from several interplanetary missions.

The Influence of Elasticity on Peristaltic Flow of Nanofluid in a Tube

In this paper, a mathematical model is proposed to study the influence of elasticity on peristaltic flow of nanofluid in a vertical tube with temperature dependent viscosity. The expressions for axial velocity, temperature, flux and pressure gradient are derived. The different nanofluids suspensions are consider to analyze the influence of elasticity on flux variation. Application of blood flow through veins is studied by expressing relationship between pressure gradient and volume flow rate in an elastic tube. The effect of different pertinent parameters on the flow characteristics of nano fluid in an elastic tube with peristalsis is analyzed through graphs. The variation in flux for different nanofluids like pure water H2O, Copper-water nanofluid CuO + H2O, Silver-water Ag + H2O and Titanium oxide-water nanofluid TiO2 + H2O are illustrated through graphs. The variation in flux for various physical parameters such as amplitude ratio, heat source parameter, Grashof number, viscosity parameter and elastic parameters are discussed. The flux takes higher values for nano particles case when compared to pure water. The flux enhances with amplitude ratio, Grashof number, heat source/sink factor and viscosity factor. The flux is more for the Titanium oxide-water nanofluid TiO2 + H2O when compared to remaining cases. The important observation is that pressure rise along mean flow rate is increase due to raise in temperature of source or sink in puming region and decreases in co pumping region. In the absence of elastic parameter (α″ = 0), the results observed in the present study are similar to that of results observed by O. A. Beg et al., Results in Physics 7, 413 (2017).

A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging.

Mitochondrial metabolism is of central importance to diverse aspects of cell and developmental biology. Defects in mitochondria are associated with many diseases, including cancer, neuropathology, and infertility. Our understanding of mitochondrial metabolism in situ and dysfunction in diseases are limited by the lack of techniques to measure mitochondrial metabolic fluxes with sufficient spatiotemporal resolution. Herein, we developed a new method to infer mitochondrial metabolic fluxes in living cells with subcellular resolution from fluorescence lifetime imaging of NADH. This result is based on the use of a generic coarse-grained NADH redox model. We tested the model in mouse oocytes and human tissue culture cells subject to a wide variety of perturbations by comparing predicted fluxes through the electron transport chain (ETC) to direct measurements of oxygen consumption rate. Interpreting the fluorescence lifetime imaging microscopy measurements of NADH using this model, we discovered a homeostasis of ETC flux in mouse oocytes: perturbations of nutrient supply and energy demand of the cell do not change ETC flux despite significantly impacting NADH metabolic state. Furthermore, we observed a subcellular spatial gradient of ETC flux in mouse oocytes and found that this gradient is primarily a result of a spatially heterogeneous mitochondrial proton leak. We concluded from these observations that ETC flux in mouse oocytes is not controlled by energy demand or supply, but by the intrinsic rates of mitochondrial respiration.

RayActive: An all-in-one R2S neutron induced activation analysis tool based on new intrinsic resolution methods.

Neutron production in nuclear facilities can induce a SDDR (Shutdown Dose Rate) even after months. Different methods exist to simulate the SDDR of neutron activated materials. The most used method is the mesh-based R2S (Rigorous-Two-Steps). This method couples a Monte-Carlo code and an isotopic inventory code to compute the SDDR. The Monte-Carlo code computes the neutron flux on a user-defined mesh to take into account the neutron flux gradients in the cells. The aim of this article is to present RayActive, a prototype tool elaborated for computing the SDDR. RayActive is based on a modified R2S method with an almost exact identification of materials enclosed in each voxel of a superimposed mesh. The CAD based geometry definition for the model makes possible this identification. Moreover, RayActive is designed as an ”all-in-one” package without any other code coupling. RayActive is designed to be as easy to use as possible and each part of the computation has been optimized to minimize the computational time. Verification and validation of RayActive has been done on shutdown dose rate benchmarks made with FLUKA code and classical R2S process coupling MCNP and FISPACT codes. Good agreement was found for these benchmarks even if some differences occur for the validation benchmark. These discrepancies show the impact on the results of the modified R2S method employed in RayActive.

Molecules with ALMA at Planet-forming Scales (MAPS). III. Characteristics of Radial Chemical Substructures

Abstract The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a detailed, high-resolution (∼10–20 au) view of molecular line emission in five protoplanetary disks at spatial scales relevant for planet formation. Here we present a systematic analysis of chemical substructures in 18 molecular lines toward the MAPS sources: IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. We identify more than 200 chemical substructures, which are found at nearly all radii where line emission is detected. A wide diversity of radial morphologies—including rings, gaps, and plateaus—is observed both within each disk and across the MAPS sample. This diversity in line emission profiles is also present in the innermost 50 au. Overall, this suggests that planets form in varied chemical environments both across disks and at different radii within the same disk. Interior to 150 au, the majority of chemical substructures across the MAPS disks are spatially coincident with substructures in the millimeter continuum, indicative of physical and chemical links between the disk midplane and warm, elevated molecular emission layers. Some chemical substructures in the inner disk and most chemical substructures exterior to 150 au cannot be directly linked to dust substructure, however, which indicates that there are also other causes of chemical substructures, such as snowlines, gradients in UV photon fluxes, ionization, and radially varying elemental ratios. This implies that chemical substructures could be developed into powerful probes of different disk characteristics, in addition to influencing the environments within which planets assemble. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.

Numerical validation of thermal conductivity of Al6061 based hybrid nano metal matrix composite filled with nanoparticles of Ni and Cr

Aluminum composite matrix materials are regarded as the most popular type of composite materials. Metal matrix composites made of aluminum have better mechanical and thermal properties, including a higher strength-to-weight ratio, tensile strength, hardness, and a low coefficient of thermal expansion. In various types of applications viz, automobile, aviation, the thermal characterization of aluminum metal matrix composites has increased. Thermal conductivity as a function of temperature, thermal diffusivity, and the thermal gradient is one of the essential thermal characteristics of aluminum metal matrix composites needed to understand the material’s behavior. The current work evaluated thermal conductivity as a product of thermal diffusivity, density, and specific heat for Al6061/Ni/Cr hybrid nano metal matrix composites from 50 °C to 300 °C. Al6061 based metal matrix composite reinforced with varying wt.% of Ni and Cr nanoparticles whereas fixed wt.% of graphene and Mg added to improve thermal conductivity, self-lubrication, and wettability. Thermal diffusivity, specific heat, and density were evaluated using laser flash apparatus (LFA 447), differential scanning calorimetry (DSC), and Archimedes principle, respectively. Results revealed that the thermal conductivity of fabricated composites increases with Ni, Cr, Mg, and graphene nanoparticles. With further expansion of reinforced particles of Ni and Cr, the thermal conductivity decreases. Finite element analysis (FEA) has been conducted to determine the thermal gradient and thermal flux using experimental values such as density, thermal conductivity, specific heat, and enthalpy at various temperature ranges to validate the experimental results.

Effect of wall temperature on the kinetic energy transfer in a hypersonic turbulent boundary layer

The effect of wall temperature on the transfer of kinetic energy in a hypersonic turbulent boundary layer for different Mach numbers and wall temperature ratios is studied by direct numerical simulation. A cold wall temperature can enhance the compressibility effect in the near-wall region through increasing the temperature gradient and wall heat flux. It is shown that the cold wall temperature enhances the local reverse transfer of kinetic energy from small scales to large scales, and suppresses the local direct transfer of kinetic energy from large scales to small scales. The average filtered spatial convection and average filtered viscous dissipation are dominant in the near-wall region, while the average subgrid-scale flux of kinetic energy achieves its peak value in the buffer layer. It is found that the wall can suppress the inter-scale transfer of kinetic energy, especially for the situation of a cold wall. A strong local reverse transfer of fluctuating kinetic energy is identified in the buffer layer in the inertial range. Helmholtz decomposition is applied to analyse the compressibility effect on the subgrid-scale flux of kinetic energy. A strong transfer of the solenoidal component of fluctuating kinetic energy is identified in the buffer layer, while a significant transfer of the dilatational component of fluctuating kinetic energy is observed in the near-wall region. It is also shown that compression motions have a major contribution to the direct transfer of fluctuating kinetic energy, while expansion motions play a marked role in the reverse transfer of fluctuating kinetic energy.

New Estimation of the NOx Snow‐Source on the Antarctic Plateau

AbstractTo fully decipher the role of nitrate photolysis on the atmospheric oxidative capacity in snow‐covered regions, NOx flux must be determined with more precision than existing estimates. Here, we introduce a method based on dynamic flux chamber measurements for evaluating the NOx production by photolysis of snowpack nitrate in Antarctica. Flux chamber experiments were conducted for the first time in Antarctica, at the French‐Italian station Concordia, Dome C (75°06'S, 123°20’E, 3233 m a.s.l) during the 2019–2020 summer campaign. Measurements were gathered with several snow samples of different ages ranging from newly formed drifted snow to 6‐year‐old firn. Contrary to existing literature expectations, the daily average photolysis rate coefficient, , did not significantly vary between differently aged snow samples, suggesting that the photolabile nitrate in snow behaves as a single‐family source with common photochemical properties, where a = (2.37 0.35) × 10−8 s−1 (1) has been calculated from December 10th 2019 to January 7th 2020. At Dome C summer daily average NOx flux, , based on measured NOx production rates was estimated to be (4.3 1.2) × 108 molecules cm−2 s−1, which is 1.5–7 times less than the net NOx flux observed previously above snow at Dome C using the gradient flux method. Using these results, we extrapolated an annual continental snow sourced NOx budget of 0.017 0.003 TgN y−1, 2 times the nitrogen budget, (N‐budget), of the stratospheric denitrification previously estimated for Antarctica. These quantifications of nitrate photolysis using flux chamber experiments provide a road‐map toward a new parameterization of the product that can improve future global and regional models of atmospheric chemistry.

Groundwater–surface water interactions in a river estuary and the importance of geomorphology: Insights from hydraulic, thermal and geophysical observations

AbstractThis study presents the groundwater flow and salinity dynamics along a river estuary, the Werribee River in Victoria, Australia, at local and regional scales. Along a single reach, salinity across a transverse section of the channel (~80 m long) with a point bar was monitored using time‐lapse electrical resistivity (ER) through a tidal cycle. Groundwater fluxes were concurrently estimated by monitoring groundwater levels and temperature profiles. Regional porewater salinity distribution was mapped using 6‐km long longitudinal ER surveys during summer and winter. The time‐lapse ER across the channel revealed a static electrically resistive zone on the side of the channel with a pronounced cut bank. Upward groundwater flux and steep vertical temperature gradients with colder temperatures deeper within the sediment suggested a stable zone of fresh groundwater discharge along this cut bank area. Generally, less resistive zones were observed at the shallow portion of the inner meander bank and at the channel center. Subsurface temperatures close to surface water values, vertical head gradients indicating both upward and downward groundwater flux, and higher porewater salinity closer to that of estuary water suggest strong hyporheic circulation in these zones. The longitudinal surveys revealed higher ER values along deep and sinuous segments and low ER values in shallow and straighter reaches in both summer and winter; these patterns are consistent with the local channel‐scale observations. This study highlights the interacting effects of channel morphology, broad groundwater–surface water interaction, and hyporheic exchange on porewater salinity dynamics underneath and adjacent to a river estuary.

East–West Proton Flux Anisotropy Observed with the PAMELA Mission

Abstract We present a study of the east–west anisotropy of trapped-proton fluxes in low-Earth orbit based on the measurements of the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) experiment. The differential intensities of eastward- and westward-traveling protons detected in the South Atlantic Anomaly region were estimated as a function of equatorial pitch angle and drift shell, for six energy bins between 80 MeV and 2 GeV. We found that, as a consequence of the strong atmospheric gradient coupled with the large gyroradius in this energy range, the intensities of eastward fluxes exceed those of westward fluxes by a factor of ∼10–20. However, the reported directional asymmetry also depends on the sign of the local flux gradient, resulting in more intense westward fluxes beyond the radial distances where the inner belt peaks. PAMELA observations can be used to improve the description of the near-Earth radiation environment at lowest altitudes and highest trapping energies, where current theoretical and empirical models are affected by the largest uncertainties.

Spatial convergence study of Lax-Friedrichs WENO fast sweeping method on the SN transport equation with nonsmoothness

Spatial convergence study of the Lax-Friedrichs fast sweeping method based on the classical third order WENO scheme (WENO3) without a priori smoothness indicators is performed on the variants of Larsen’s benchmark problem with nonsmooth solutions. For comparison, third order upwind (UPWD3), weighted diamond difference, step method, bilinear discontinuous finite element method are also included. In optically thick regimes of the cases with continuous angular fluxes, WENO3 detects steep gradients of angular fluxes and handles them as discontinuities to suppress the unphysical oscillation, which improves the accuracy significantly compared with UPWD3. In the cases with discontinuous angular fluxes, WENO3 achieves non-oscillatory solutions with limited numerical diffusion. Nonlinear Gauss-Seidel iteration is necessary to obtain convergent solution for the nonlinearity of WENO3, which leads to low computational efficiency. The convergence behavior of nonlinear Gauss-Seidel iteration is affected by nonsmoothness of the exact solution, mesh number and the relaxation parameter.

A mixture theory analysis for reflection phenomenon of homogeneous plane-P1-wave at the boundary of unsaturated porothermoelastic media

SUMMARY A mixture theory is employed to analyse the reflection behaviour of a homogeneous plane-P1-wave at the boundary of an unsaturated porothermoelastic medium. A non-isothermal dynamic model is employed which takes into account the interaction between the pore fluids and the solid phase of the porous material. In such an unsaturated porothermoelastic cases, the theoretical expressions of the amplitude reflectivity and energy ratio for five kinds of reflected waves generated by the incidence of homogeneous plane-P1-wave, that is reflected P1, P2, P3, S and thermal waves, are derived by taking into consideration of the traction-free, water-permeable, air-permeable and adiabatic boundary conditions. The numerical results are obtained and utilized to discuss the relationship between the amplitude reflectivity and energy ratio of each reflected wave and the thermophysical parameters of the unsaturated porothermoelastic media. The results show that the amplitude and energy carried by the incident wave are mainly occupied by reflected P1 wave and reflected S wave. The amplitude reflectivity and energy ratio of each reflected wave is not just related to the incident angle but also affected by the saturation, thermal expansion coefficient and initial reference temperature. The phase lags of the heat flux and temperature gradient and the thermal conductivity only have a large effect on the amplitude reflectivity and energy ratio of reflected thermal wave.

Analytical Investigation of Non-Fourier Bioheat Transfer in the Axisymmetric Living Tissue Exposed to Pulsed Laser Heating Using Finite Integral Transform Technique

Abstract This article proposes the closed-form solution of the generalized non-Fourier model-based bioheat transfer equation (BHTE) in Cylindrical coordinates to understand the thermal behavior of living tissue heated by a pulsed laser. The axisymmetric living tissue exposed to the non-Gaussian temporal profile of laser heating has been considered to investigate the non-Fourier bioheat transfer phenomena. The closed-form solution of the generalized non-Fourier model-based BHTE with time-dependent thermal energy generation has been obtained through the finite integral transform (FIT) technique. The analytical solution was juxtaposed to the corresponding numerical solution in order to determine its reliability. The numerical solution of the aforementioned governing equation has been obtained by the finite volume method (FVM). The results of both analytical and numerical solutions have been verified using results given in published literature. Subsequently, the dual-phase-lag (DPL) model's findings were juxtaposed to those obtained using the hyperbolic and traditional Fourier models. The effect of different parameters like relaxation times corresponding to the temperature gradient and heat flux, metabolic energy generation, and blood perfusion on the resultant temperature distribution inside the axisymmetric living tissue exposed to pulsed laser heating has been discussed. The importance of this study might be found in various applications such as laser-based-photothermal therapy, melting of the surface of metal and alloys by laser heating.

Equivalent hydraulic conductivity, connectivity and percolation in 2D and 3D random binary media

The equivalent hydraulic conductivity (Keq) relates the spatial averages of flux and head gradient in a block of heterogeneous media. In this article, we study the influence of connectivity on Keq of media samples composed of a high conductivity (k+) and a low conductivity (k−) facies. The k+ facies is characterized by a proportion p, and also by two connectivity parameters: a connectivity structure type (no, low, intermediate, high), and a correlation integral scale lc.The probability distribution of Keq, and the critical value of p at which percolation occurs (pav), are studied as a function of these connectivity parameters. The distribution of log(Keq) is Gaussian in all cases, so the results are presented in terms of the geometric mean (〈Keq〉) and the variance (σlog(Keq)2).Both quantities show a data collapse if expressed as a function of p−pav (for the variance σlog(Keq)2, notably, even if 2D and 3D data are plotted together). In 3D, when a connectivity structure exists, Keq is always greater than when no structure exists, and increases (while pav decreases) as lc increases. The same is observed in 2D, except for the low connectivity structure type (i.e. when the k+ facies is disconnected), that shows an unprecedented behaviour: Keq is greater in the absence of structure, and decreases (pav increases) as lc increases. Our results show that any influence of connectivity on Keq is well accounted for simply by a shift in the percolation threshold pav, and then, suggest that Keq is controlled mainly by the proximity to percolation.

A central-upwind scheme for two-layer shallow-water flows with friction and entrainment along channels

We present a new high-resolution, non-oscillatory semi-discrete central-upwind scheme for one-dimensional two-layer shallow-water flows with friction and entrainment along channels with arbitrary cross sections and bottom topography. These flows are described by a conditionally hyperbolic balance law with non-conservative products. A detailed description of the properties of the model is provided, including entropy inequalities and asymptotic approximations of the eigenvalues of the corresponding coefficient matrix. The scheme extends existing central-upwind semi-discrete numerical methods for hyperbolic conservation and balance laws and it satisfies two properties crucial for the accurate simulation of shallow-water flows: it preserves the positivity of the water depth for each layer, and it is well balanced, i.e., the source terms arising from the geometry of the channel are discretized so as to balance the non-linear hyperbolic flux gradients. Along with the description of the scheme and proofs of these two properties, we present several numerical experiments that demonstrate the robustness of the numerical algorithm.

UNS3D Near-Field Predictions for the Third AIAA Sonic Boom Prediction Workshop

This paper presents the results of turbulent flow simulations prepared for the Third AIAA Sonic Boom Prediction Workshop. Solutions were prepared for two geometries that exhibited shock–plume interaction features: the NASA biconvex shock–plume interaction wind-tunnel model, and the NASA C608 low-boom concept aircraft. The unstructured, finite volume Navier–Stokes solver UNS3D was used to predict the turbulent near-field flow with Menter’s shear stress transport turbulence model. Four solver setups with different combinations of the flux function, gradient reconstruction, and slope limiter were applied to each geometry. UNS3D predictions were compared against a grid-specific ensemble dataset created using workshop participant submissions and experimental data when available. Predictions of the biconvex geometry were found to be in good agreement with both the experimental and ensemble datasets. The weighted least-squares with QR decomposition (LSQR) gradient reconstruction approach was only successful for the biconvex geometry, with no converged cases being achieved on C608 grids. The Dervieux limiter, used only to aid simulations on the C608 using weighted LSQR, was observed to be too dissipative to be of practical use. Near-field predictions of the C608 geometry using Green–Gauss gradient reconstruction and a modified Venkatakrishnan limiter were found to correlate well with the ensemble data. The perceived level of the resulting sonic boom carpet was 1.5 dB quieter along the first 20 deg of the carpet than the ensemble mean, and it peaked at an azimuth angle of 30 deg with a value of 76.1 dB. A study of the undertrack near-field pressure signature revealed the components of the predicted signatures responsible for the variances observed in the sonic boom carpet.

Why does rapid contraction of the radius of maximum wind precede rapid intensification in tropical cyclones?

AbstractThe radius of maximum wind (RMW) has been found to contract rapidly well preceding rapid intensification in tropical cyclones (TCs) in recent literature but the understanding of the involved dynamics is incomplete. In this study, this phenomenon is revisited based on ensemble axisymmetric numerical simulations. Consistent with previous studies, because the absolute angular momentum (AAM) is not conserved following the RMW, the phenomenon can not be understood based on the AAM-based dynamics. Both budgets of tangential wind and the rate of change in the RMW are shown to provide dynamical insights into the simulated relationship between the rapid intensification and rapid RMW contraction. During the rapid RMW contraction stage, due to the weak TC intensity and large RMW, the moderate negative radial gradient of radial vorticity flux and small curvature of the radial distribution of tangential wind near the RMW favor rapid RMW contraction but weak diabatic heating far inside the RMW leads to weak low-level inflow and small radial absolute vorticity flux near the RMW and thus a relatively small intensification rate. As RMW contraction continues and TC intensity increases, diabatic heating inside the RMW and radial inflow near the RMW increase, leading to a substantial increase in radial absolute vorticity flux near the RMW and thus the rapid TC intensification. However, the RMW contraction rate decreases rapidly due to the rapid increase in the curvature of the radial distribution of tangential wind near the RMW as the TC intensifies rapidly and RMW decreases.

Application of data driven machine learning approach for modelling of non-linear filtration through granular porous media

Modeling the relationship between volumetric flux (m3/s) and gradient of hydraulic head (m) is extremely challenging in case of non-linear filtration through porous packing. Due to the uncertainties associated with the definition and quantification of characteristic length and velocity, experimental, theoretical and numerical modelling approaches are not widely applicable. The machine learning algorithms have proven to be extremely useful for predicting similar situations when the physical process is too complex to understand. The performance of Artificial Neural Network (ANN), Random Forest (RF), and Boosted Tree methods have been investigated in the study for predicting the gradient of hydraulic head (target variable) in case of non-linear filtration through porous packing. Velocity of flow, media size, porosity, kinetic viscosity, and shape factor obtained from a wide range of reported data in the literature was used as input features. All three models were observed to predict the output values with significant accuracies (R2>0.90) for wide range of data obtained from different sources. A RF method based sensitivity analysis was performed to study the relative importance of different hydrological parameters over the target variable. These parameters in terms of a decreasing order was ranked as velocity, diameter, viscosity, porosity, and shape factor. These type of models can aid the researchers, planners, and designers to predict the hydraulic gradient or volumetric flux in multiple scenarios associated with non-linear filtration through porous media such as oil and gas exploration wells, water filters, rockfill dams etc.

Thermal‐hydraulic analysis of UO2 and MOX fuel considering different cladding materials at various burnup levels in pressurized water reactor

AbstractThermal analysis of fuel elements with UO2 and mixed‐oxide (MOX) fuels at different fuel burnup levels has been performed analytically and by simulation using ANSYS. Results showed that UO2 incurred a lower fuel temperature than MOX under all conditions. Higher fuel element temperatures were obtained for higher levels of burnup for UO2 fuel. For MOX fuel, higher temperatures were obtained for low and high burnup fuel. Radial temperature, thermal gradient, and thermal heat flux were determined across reactor pressure vessel (RPV), demonstrating the highest value at the center of the RPV. The maximum linear power density was determined for UO2 and MOX, showing that using UO2 fuel at 2 at% burnup rendered the highest allowable linear power density. Furthermore, the transient analysis showed that there was a small rise in fuel temperature for a decrease in mass flow rate from 100% to 60% followed by a rapid increase in temperature for further reduction in flow rate.