Commercial Computational Fluid Dynamics Tool Research Articles

Analysis of submersible axial flow pump fitted with variable IGV at design and off-design conditions

Abstract Submersible axial flow pump is capable of generating large flow rate at high efficiency and is widely used in agriculture, irrigation, water supply and drainage in factories, urban areas, etc. Pumps are always designed to operate at the designed conditions of flowrate and head, but in certain practical applications, their off- design operation seems to be more important, like if there is waterflooding due to heavy rainfall or in case of variable flowrate, variable head operations or long-distance water supply. These situations arise for limited operation (time) and hence it is not economical to change the existing pumping system. The present work deals with the analysis of submersible axial flow pump at design as well as off-design conditions. This off-design operation was controlled by the variable inlet guide vane (VIGV) with the task of making it energy efficient for all conditions. The scope of this work was to investigate the performance of selected pump at designed rotational speed, at designed flowrate (Q/Qd =1) as well as Q/Qd =0.8 and Q/Qd =1.2, using Computational Fluid Dynamics (CFD) and at various VIGV angles in the range of ±25°. The fluid flow analysis was performed using commercial CFD tool ANSYS CFX v17.0. From the numerical study, it was concluded that the performance of the considered AFP significantly increased due to the presence of VIGV at positive rotation angles. The best performance was observed for IGV angle of +25° for all flowrates. As compared to the reference case of 0° IGV rotation, the performance of the AFP increased by 28.42% in terms of head ratio and 0.235% in terms of hydraulic efficiency, for +25° IGV angle, at the designed flowrate. Also, an increment of 69.05% in terms of head ratio and 14.49% in terms of hydraulic efficiency was observed at overload condition of Q/Qd =1.2.

Performance Prediction, Optimisation and Validation of a CNG Engine Intake Manifold of a Commercial Vehicle Using Transient CFD Analysis

Developing countries like India have large consumer markets driven by huge demands. Commercial vehicles play a critical role in full filing these demands. Commercial vehicles increasingly face stringent emission norms criteria and hence designing an ICE-powertrain with optimum operating efficiency becomes paramount. Intake manifold is the critical part of an internal combustion engine that supplies fuel/ air mixture to all the cylinders combustion chambers. It ensures a uniform mixture at cylinder inlet for better mixing inside the cylinders for better volumetric efficiency. Uneven distribution of fuel/air mixture causes unstable torque and unburnt fuel which fails to meet the emission norms. It also results in uneven temperatures in each cylinder because of cylinder misfiring. In current paper, 3D Computational Fluid Dynamics (CFD) simulations are carried out to investigate the variance and uniformity of CNG/air mixture at the outlet of intake manifold. Commercial CFD tool Ansys Fluent is used to study the flow distribution of mixture inside the manifold and runners. Initial estimation of flow pattern is done by performing a steady state simulation to predict the uniformity index of CNG at cylinder inlet. For detailed investigation, transient simulation is performed by taking fresh air and CNG mass flow rate as a function of crank angle. In this paper, mesh dependence study was done initially to achieve an optimum cell count with good accuracy. A detailed transient analysis using multi-species modelling for air & CNG was done using automated scripts with time steps as small as 1 degree crank angle rotation coupled with injection pressure and injection timing study. This helped to identify critical areas and optimise the design to improve the mass flow rate variance from 15-20% for baseline case to 6-7% for final design, and also improve the uniformity index. It also helped reduce the CNG engine mis-firing issue. The results have been well validated with Laboratory Test Results.
 

Effect of duct geometry on thermal management of PCM – Liquid hybrid PV panel

In this study, a computational fluid dynamics (CFD) model of a PV panel with different cooling technologies is performed. The basic setup consists of a hybrid PV-PCM system, with absorber plate of 0.25m breadth, 0.5m length and 5mm thickness. The study includes the design and simulation of a three-dimensional photo-voltaic model integrated with a water channel and PCM. A commercial CFD tool ANSYS Fluent is used to analyse the thermal transport. The melting of the PCM is simulated using enthalpy – porosity method. Effect of shape and orientation of duct cross-section on the performance of the system is investigated. The cross section dimensions are chosen so as to maintain negligible difference in the volume on PCM. The Reynolds number in each model is maintained constant (Re = 1500) to have similar flow characteristics, so that only the effect of shape on heat transfer can be analysed. Additionally, a PCM-PV model with circular cross-section duct was modelled and compared to triangular, square, rectangular and ellipse cross-section. From the results obtained, it was found that there was a minimum temperature drop of 20oC between simple PV model and PV-PCM model. Triangular shapes had highest thermal efficiencies, with an average of 46%, Square duct showed better electrical efficiency, with an average of 13.25% with same pressure drop as circular ducts. Orientation of duct showed a huge impact on thermal and electrical efficiencies of rectangular channel.

Implementation of the Marangoni effect in an open-source software environment and the influence of surface tension modeling in the mushy region in laser powder bed fusion (LPBF)

Tangential surface tension forces on a gas–liquid interface due to surface tension gradients have been implemented in the computational fluid dynamics (CFD) solver icoReactingMultiphaseInterFoam provided by the open-source software environment of OpenFOAM OpenCFD Ltd (ESI Group) OpenFOAM (online) https://www.openfoam.com/ (accessed 21 May 2021), so that the Marangoni effect can be taken into account, which is a main driver of heat transfer in additive manufacturing processes that comprise a melt pool. The solver surpasses the capabilities of similar open-source projects by considering a wide range of physical effects, e.g. multiple phases, melting, solidification, evaporation, and laser beam heat sources with an arbitrary intensity distribution and thus makes it an appealing framework, especially for the simulation of the laser powder bed fusion (LPBF) process. Herein, all relevant details and derivation considering the Marangoni effect are provided and validated by means of a benchmark problem by comparing the obtained results with the available analytical solution, with the results obtained from a commercial CFD tool and with the results of other authors. The modified solver is additionally validated by comparing the results from LPBF simulations with experimental data. Furthermore, the influence of the surface tension modeling on the mushy region is investigated. The optimized implementation shows improvements of the simulation results in both the dimensions and shape of the melt pool and the resulting surface with regard to the experimental data.

A study on the efficient numerical analysis for the prediction of full-scale propeller performance using CFD

In Computational Fluid Dynamics (CFD) simulations, limited full-scale studies with ship propellers have been conducted due to the limitation of computational resources and computation time. Two methods for efficient numerical analysis of full-scale propeller performance are; (1) a method of using large dimensionless wall distances (y+) at a full scale and (2) a method of applying a virtual fluid at a model scale. Thus, the aim of this study is to investigate the effect of different wall y+ values in a real fluid and the virtual fluid concept to predict full-scale propeller performance using CFD. For these investigations, the commercial CFD tool, STAR-CCM+, was used to predict the propeller open water (POW) performance of the KCS propeller (KP505) in a model and full-scale. The findings of this research study support the use of a small value of wall y+ (i.e., y+<1) for the model scale simulations, but the effect of the wall y+ is negligible in full-scale. This study also demonstrates that the similarity requirements for the advance coefficient and Reynolds number could be satisfied simultaneously in full-scale by using the virtual fluid properties without any need to conduct more computationally demanding full-scale simulations with real fluid.

The effect of appendages on ship resistance

The availability of the robust commercial computational fluid dynamics (CFD) software and the increasing power of high-performance computers (HPC) boosts the use of CFD techniques for numerical investigations of ship hydrodynamimcs performaces. Nowadays, CFD tools provide a rather accurate solution for complex physical phenomena, such as wave braking, turbulence, flow detachment and overturning. Consequently, the ability to capture this fenomena allows a detailed insight into the flow mechanism that trigger and sustain them.The paper focuses on a numerical investigation of flow around hull a fully appended ONR Tumblehome model 5613. Due to special operation conditions, naval ships are equipted with a large number of appendages such as sonar domes, brackets, twin propeller shafts and twin rudders. Position and alignment of these appendages are essential in order to avoid the increased resistance, decreased propulsive efficiency and cavitation. NUMECA/FineMarine commercial code has been used to evaluate the flow field around ONRT (Office of Naval Research Tumblehome) hull and to estimate the effect of the appendages on ship hydrodynamics performances. Comparison with experimental towing tank results showed good agreement with a difference of up to 2%.

Numerical assessment on the performance of variable area single- and two-stage ejectors: A comparative study

The two-stage ejector has been suggested to replace the single-stage ejector geometrical configuration better to utilize the discharge flow’s redundant momentum to induce secondary flow. In this study, the one-dimensional gas dynamic constant rate of momentum change theory has been utilized to model a two-stage ejector along with a single-stage ejector. The proposed theory has been utilized in the computation of geometry and flow parameters of both the ejectors. The commercial computational fluid dynamics tool ANSYS-Fluent 14.0 has been utilized to predict performance and visualize the flow. The performance in terms of entrainment ratio has been compared under on- design and off-design conditions. The result shows that the two-stage ejector configuration has improved (≈57%) entrainment capacity than the single-stage ejector under the on-design condition.

Numerical Modeling of Freestream Turbulence Decay Using Different Commercial Computational Fluid Dynamics Codes

Abstract This work models the spatial decay of freestream turbulence using three different commercial computational fluid dynamics (CFD) codes: Fluent, star-ccm+, and cfx. The two-equation shear stress transport k–ω (SST-k–ω) steady Reynolds-averaged-Navier–Stokes (RANS) model was used, within each of these three different commercial codes, and the modeling variations were analyzed. Comparison of the results from the SST-k–ω model with experiments and large eddy simulation (LES) (carried out using star-ccm+) were also made, which reveal that all the commercial CFD codes demonstrate either a higher or slower rate of spatial turbulent kinetic energy (TKE) decay. Attempts were then made to unify the resultant modeling approach between these three CFD tools, by careful manipulation of the inlet boundary conditions and subsequent fine-tuning of the SST-k–ω model constant (β∞∗). The results obtained not only displayed uniformity among the three CFD codes but also demonstrated a much better agreement to the experiments and the LES results. Thereafter, the optimized model coefficient (β∞∗) was integrated with the three-equation k–kl–ω transition model to examine its applicability in modeling a turbulent boundary layer flow over a flat plate with low incoming turbulence. The results showed good agreement with the theoretical boundary layer correlations, with correct prediction of the transition location. The findings from this study can be used as a suitable modeling method to accurately model the effects of freestream turbulence on bluff-body and boundary layer flows.

Performance Optimization of Ejector using Computation Fluid Dynamics

Ejector is a device used for carry low pressure fluids with no mechanical force, high pressure flow. This contains the main nozzle, chamber for suction, chamber for mixing and diffuser.It is used in vaccum pumps, condensers, steam refrigeration, Because of its simple structure, gas mixing, pneumatic transport (no moving parts) and reliable operation. It is also used in pumps for lifting slurries and waste material containing solids from tanks and sumps. Due to their simplicity and high reliability, however, jet ejectors are widely used in industries with low efficiency. The project's goal is to optimize the efficiency of jet ejectors for each operating condition.Consequently, the primary fluid consumption and operating cost is minimized. A commercial computational fluid dynamics tool would be used to analyse the flow characteristics inside the ejector geometry. The results of the CFD simulation could be used to understand the effect of fluid velocity and pressure ratio on the ejector performance. The analysis would also be carried out by varying the primary and secondary nozzle dimensions. Performance of ejectors under various operating conditions is generally obtained through an experimental testing of prototype or scaled ejectors. The availability of performance parameters for such ejectors is limited, and experimental testing can be cost prohibitive.

Effect of Inlet Boundary Layer Suction on Flow Distortion in Subsonic Diffusing S-Duct

The effects of the boundary layer suction (BLS) near the S-duct inlet on the flow distortion of the S-duct were analyzed using a commercial computational fluid dynamics tool. The purpose of this study was to investigate the effect of shape factors on the location and length of the BLS for the RAE M 2129 S-duct with the inlet shape AR (0.75,0). The performance of the S-duct is influenced by the boundary layer thickness for duct flow and the counter-rotating vortex position on the engine face. All of the cases upon applying BLS were confirmed as having a different boundary layer thickness and the counter-rotating vortex at the engine face was confirmed. The PS (0,0.1) case has the thinnest boundary layer and the counter-rotating vortex is the farthest from the starboard side, while the PS (0.06,0.08) case has the thickest boundary layer and the counter-rotating vortex is located near the starboard side. In conclusion, it was confirmed that BLS has a significant influence on the flow distortion for the applied position compared to the applied length. Additionally, the PS (0,0.1) case applied near duct inlet showed the least flow distortion, and the PS (0.06,0.08) case located near the cowl lip showed the largest flow distortion.

Effect of aspect ratio of elliptical inlet shape on performance of subsonic diffusing S-duct

The aerodynamic characteristics of S-ducts with various inlet shapes were analyzed using a commercial computational fluid dynamics tool. This study aimed to investigate the influence of the aspect ratio of inlet geometry for an RAE M 2129 S-duct. The computational results were validated using experimental data from the Aircraft Research Association. The performance of the S-duct was influenced by the location of the counter-rotating vortex on the engine face. When the center of the vortex was near the starboard side, the performance was poor. By contrast, performance increased as the counter-rotating vortex moved away from the starboard side. The center of the counter- rotating vortex of the upper half semicircular S-duct was far from the starboard side, whereas that of the lower half semicircular Sduct was near the starboard side. In conclusion, S-ducts with upper half semicircular shape had better performance than those with other inlet shapes. The AR(0.75,0) case delivered the best performance, whereas the AR(1,1) case exhibited the worst.

Numerical analysis and acoustic optimization of a detached splitter plate applied for passive cylinder wake control

Computational aeroacoustics simulations require a considerable amount of time, which makes the comparison of a large number of different geometric designs a difficult task. The goal of the present study were to provide a suitable methodology for aeroacoustic optimization. By means of numerical analyses using commercial computational fluid dynamics tools (Ansys Fluent), the application of a detached splitter plate in the turbulent wake of a circular cylinder as a passive control method for noise generation was investigated. We have employed two-dimensional URANS simulations, so this case can be considered a toy problem, which contains the main challenges of the physical problem and could indicate trends correctly, but was simplified in order to decrease the computational cost to an affordable level, at the cost of making comparison with experimental data not possible. The irradiation of noise caused by the interaction between the flow and both bodies was evaluated using computational aeroacoustics tools based on the Ffowcs-Williams and Hawkings method. Using a commercial optimization software package (modeFRONTIER), various design optimization methodologies were applied to this flow in order to achieve a possible optimal configuration, i.e., one which is capable of reducing the far field noise level without increasing the aerodynamic forces. Using a multi-objective optimization tool, it was possible to evaluate the behavior of heuristic optimization algorithms and the major advantage of algorithms based on response surface methods when applied to a nonlinear aeroacoustics problem, since they require a smaller number of calculated designs to reach the optimal configuration. In addition, we applied a partitive clustering technique to identify and group the cases simulated into five clusters based on their geometric parameters, overall sound pressure level and RMS of the drag coefficient, confirming the efficiency of the application of long detached splitter plates placed next to the cylinder in stabilizing the turbulent wake, whereas the positioning of splitter plates at a distance larger than a critical gap increased the overall sound pressure level radiated due to the formation of vortices in the gap.

Effect of fluid channels on flow uniformity in complex geometry similar to lattice brick setting in tunnel kilns

This paper reports the results of air flow in tunnel kilns using a 3D computational fluid dynamics (CFD) model. A mesh sensitivity analysis was performed, and the model was validated against experimental results. Three turbulence models that are available in general purpose commercial CFD tools, namely k–ω, standard k–ε, and RNG k–ε were tested, and the k–ω model provided results that were the closest to the experimental data. The numerical results demonstrated fluid flow malfunctions in tunnel kilns, using the size of fluid channels as for the experiment, including an intriguing phenomenon of long flow separation zone behind the brick setting. Homogenous flow was achieved by optimizing the dimensions of the side wall channels, the column channels, the ceiling channel, and the extension channels. The uniform flow, in tunnel kilns, is accomplished when the dimension of the column, wall, ceiling and extension channels was 0.5, 0.25, 0.2 and 0.36 of the column width of the brick setting. Although the pressure drop in the flow uniformity case is larger than that in the base case, the advantages of short baking time and enhanced quantity and quality of produced bricks far exceed the increase in pumping power.

NUMERICAL MODELING OF FLOW AND MASS TRANSFER EFFECT ON FLOW-ACCELERATED CORROSION IN CONSECUTIVE ELBOWS

Elbows are the most common fittings in piping systems of nuclear power plants, and can experience enhanced flow-accelerated corrosion (FAC) thinning rates in comparison to the straight pipe. When 2 elbows are in close proximity, the flow through the upstream elbow may influence the mass transfer and FAC thinning rate in the downstream elbow. Therefore, the flow condition and the corresponding mass transfer coefficient (MTC) determine the local distribution of FAC wall thinning in the elbows. This paper presents the numerical analysis of the MTC (in nondimensional form, Sherwood number) and its enhancement factor in small-bore piping (1″ inner diameter) under single-phase flow conditions, for 3 arrangements of 2 consecutive elbows: (i) in-plane S-configuration, (ii) in-plane C-configuration, and (iii) out-of-plane configuration. The commercial computational fluid dynamics tool ANSYS FLUENT® is used to simulate the flow and mass transfer for the various elbow configurations. The numerical results for the MTC enhancement factors for the 3 piping configurations agree with the experimental results. To apply these small-bore results to large-bore operating conditions found in nuclear power plants, the effect of Reynolds number is also considered. The results show that the MTC enhancement factors of the downstream elbow, affected by the upstream flow, is higher than that of the upstream elbow for all 3 consecutive elbow configurations.

Heat Transfer in Diesel and Partially Premixed Combustion Engines; A Computational Fluid Dynamics Study

ABSTRACTThis article presents findings from a Computational Fluid Dynamics (CFD) study performed on the heat transfer characteristics of diesel and partially-premixed combustion (PPC) engines. The study is confined to the combustion bowl, where numerical simulations have been performed on a part of the engine cycle, namely the compression, combustion, and expansion phases. Three engine geometries were simulated and after validating the results with experimental data, parameter variations were carried out, in order to estimate their effects on the heat transfer, engine performance, and emission levels. The work was performed using a commercial CFD tool, with which only a part of the engine cylinder was modeled, the enclosure of one spray. The results highlight some important characteristic differences between the conventional diesel combustion and the low-temperature combustion scheme PPC. The reduced in-cylinder temperatures for the PPC case lead to a reduced production of NOx and soot emissions, without compromising the engine performance, only a small penalty in the increased intake air pressure is found. The importance of an appropriate injection strategy was also highlighted, as the presence of a pilot injection during the compression stroke enhanced the temperature stratification in a PPC engine. This leads to reduced heat losses and improved engine efficiency. Finally, the shape of the combustion bowl was shown to have significant effects on both heat losses as well as emission levels.

Numerical modelling of gas dispersion using OpenFOAM

In the current work the rhoReactingBuoyantFoam solver was customised for performing gas leak and gas dispersion modelling. Using experimental data from gas leaks the proposed modelling was investigated for subsonic and sonic releases. The gas molar fraction and velocity decay along the jet centreline were calculated using the modified reacting solver, and the numerical findings were compared with available experimental data. Different approaches for the turbulence closure problem were considered using standard two-equation models. The numerical stability of the solver was also investigated varying the CFL number for a set of simulations. The work also considered the modelling of gas cloud volume in a real engineering case. Standard computational setup for ANSYS-CFX was applied, and the same set of scenarios were modelled in OpenFOAM using the modified rhoReactingBuoyantFoam solver. The analysis considered 5 different leak directions and 4 wind directions in a typical industrial site.For all scenarios simulated, very good agreement with experimental data and with the commercial CFD (computational fluid dynamics) tool considered in this study was observed. The results are within 10% tolerance intervals. Detailed information of the modelling is also provided, which enable any CFD user to reproduce the results and also apply it for future analysis.

Numerical Simulation of Thermal Comfort Performance in a Room with Different Insulating Materials Using Computational Fluid Dynamics&lt;sup&gt;&lt;/sup&gt;

Numerical simulation studies are carried out for improvement of energy efficiency in a room by with different thermal insulating materials using computational fluid dynamics (CFD). The study considered various building insulating materials (BIM’s) such as: (a) Expanded Polystyrene (EPS) (b) Fiber Glass (Resin bonded (RB)-Glass wool) (c) Polyurethane Foam (PUF) and (d) Cement Plaster (CP) along with composite bricklayer combination. A multi-physical 3D model room of size 2.6 m × 2.6 m × 2.6 m is created to analyze the performance of different insulating materials using CFD simulations. The experimental data of 24 hr temperature cycle of the ambient air is used for the analysis of performance of thermal comfort inside the room with the incorporation of different thickness of the insulating materials. The thickness of insulation 0.03, 0.1, 0.2 and 0.3 m is applied on interior side of walls and roof of the building. The study performed with different grid sensitiveness for coarse, medium and fine meshes for the improvement in the accuracy of the results. The fine grid mesh analysis is chosen to carry the further studies to compare the insulated and non-insulated condition for the thermal behavior inside the room. The result shows that the thermal conductivity and heat capacity of insulated walls are very important to be taken into account for carrying out detailed thermal analysis of buildings. The studies are carried out using commercial CFD tool of ANSYS CFX 15.0. The results of comparison shows that it is possible to maintain needed thermal comfort conditions in the room while reducing the total energy consumptions at the same time by appropriate use of BIM’s.

Characterization of air-cooled heat transfer using round and slot nozzles

Many industrial facilities, such as the widely used cooling tower, transfer heat to the atmosphere. The most common cooling media are water and air. The performance of cooling equipment depends upon such factors as flow rate, pressure at the nozzle tip, and the type of nozzle. In this article, round and slot nozzles with air as the cooling medium are studied to verify their cooling effectiveness. The heat transfer characteristics of these nozzles, compared using three different methodologies, are presented. A commercial computational fluid dynamics tool, FLUNET, is employed to model the 3D thermal-fluidic field of each nozzle. A 1D source code is also implemented in FORTRAN to achieve a faster and more reliable solution. Finally, experimental data are used to verify the two computational results. The difference between the results obtained using the FORTRAN code and FLUENT was about 0.07%. The temperatures at the cooling tower exit for the 1D and 3D codes were 431.9°C and 432.2°C (809.4°F and 810°F), respectively. Four sets of experimental data were compared with the numerical results. The maximum temperature difference between the 1D model and the measurements occurred at an inlet temperature of 450°C (842°F) and at a strip thickness of 2.28 mm. The outlet temperature from the 1D model and measurement was, respectively, 290.1°C and 278.5°C (554.2°F and 533.3°F), differing by approximately 4%. The 1D model generates good temperature predictions compared to measurements from a real cooling tower. This result would be very beneficial for industries that require fast temperature information for stable and steady operation, such as steelworks.

Numerical evaluation of SmCo permanent magnet flowmeter measuring sodium flow in a low flow rate regime using FLUENT/MHD module

One of the several key subsystems in the test facility of Korean sodium-cooled fast reactor is a plugging meter system, which measures the impurities in the sodium using an indirect online technique. To measure the low flow rate, a permanent magnet flowmeter was developed owing to its inherent fast response time, non-invasive characteristic, relatively accurate flow rate measurements, and excellent linearity between the flow rate and flowmeter signal. However, several limitations have been reported in the experimental evaluation of the flowmeter under low flow rate conditions given the measurement capability of the current experimental facility. Thus, the performance of the flowmeter was evaluated numerically using a commercial computational fluid dynamics tool, a FLUENT/MHD module, based on the finite volume method with the help of electromagnetic analysis software, ANSYS MAXWELL. The FLUENT/MHD module was validated by comparing the simulation results with the experimental results. The relative error of the FLUENT simulation was estimated to be approximately 0.24% compared with the experimental results. After the validation process, MHD simulations were conducted to calculate the flowmeter voltage signals versus flow rates, especially in a low flow rate regime, where the linearity between the flow rate and flowmeter signal was carefully analyzed.

Computation fluid dynamics analysis of the Reactor Cavity Cooling System for Very High Temperature Gas-Cooled Reactors

The design of passive heat removal systems is one of the main characteristics of the modular Very High Temperature Gas-Cooled Reactors (VHTR) vessel cavity. The Reactor Cavity Cooling System (RCCS) is a key heat removal system during normal and off normal conditions. The design and validation of the RCCS is necessary to demonstrate that VHTRs can survive the postulated accidents. The commercial Computational Fluid Dynamics (CFD) STAR-CCM+/V5.02.009 code was used for three-dimensional system modeling and analysis of the RCCS. Different RCCS geometries and configurations were investigated to analyze heat exchange in the VHTR cavity. Sensitivity analyses over the RCCS cavity height and cooling panel location with respect to the reactor pressure vessel (RPV) wall were performed. The objective of the present work was to use CFD tools for addressing the behavior of the RCCS following accident conditions.Heat removal from the RPV through the RCCS system during normal and off normal conditions is accomplished through radiation, convection and conduction heat transfer modes. The interaction of all three heat exchange mechanisms makes it very challenging to have an accurate description of the RCCS heat transfer dynamics during normal and transient conditions. A systematic analysis of the cavity layout was performed to address the influence of different geometrical parameters on the balance of heat transfer across the RCCS cavity. Mesh convergence was achieved with an intensive parametric study of the different geometrical configurations and boundary conditions selected. Based on the results of previous studies, the Realizable k–ε turbulence model with Two-Layer all y+ wall treatment was used for the analyses discussed in the present work. The numerical results demonstrated that the CFD analyses can resemble the behavior of the full RCCS system from an integral effect point of view, with the main physical phenomena accurately reproduced by the CFD model.