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The automotive industry is increasingly focused on developing more energy-efficient and eco-friendly air-conditioning systems. In this context, CO2 microchannel gas coolers (MCGCs) have emerged as promising alternatives due to their low global warming potential (GWP) and environmental benefits. This paper explores the application of machine learning (ML) algorithms to predict the thermohydraulic performance of MCGCs in automotive air-conditioning systems. Using data generated from an experimentally validated numerical model, this study compares various ML techniques, including both linear and nonlinear regression models, to forecast key performance metrics such as refrigerant outlet temperature, pressure drop, and heat transfer rate. Spearman's correlation was employed to develop performance maps, whereas the R2 and MSE metrics were used to evaluate the models' predictive accuracy. The linear models gave around 70% forecasting accuracy for pressure drop across the gas cooler and 97% accuracy for refrigerant outlet temperature, whereas the nonlinear models achieved more accurate predictions, with an accuracy ranging from 71% to 99%. This implies that nonlinear regression generally performs better than linear regression models in assessing the overall thermohydraulic performance of microchannel gas coolers. This research brings forth new ideas on how ML methods can be applied to enhance efficiency and effectiveness in gas coolers, contributing to the development of more eco-friendly automotive air-conditioning systems. [ABSTRACT FROM AUTHOR]

Solar energy could be used to generate both electricity and heat with the aid of photovoltaic thermal (PV/T) systems. Although the systems have a variety of advantages, they nevertheless hold a significant constraint. The system suffers a susceptible constraint wherein the photovoltaic (PV) module experiences an increase in temperature due to exposure to solar irradiation. The integration of a cooling system is necessary to enhance its operational efficiency. A novel approach, known as the reversed circular flow jet impingement (RCFJI), was proposed as a means to improve the performance of a PV/T collector. The current work seeks to assess the thermohydraulic and electrohydraulic performance of the RCFJI PV/T collector. The experiment was conducted under an irradiance level of 500–900 W/m2. From the result obtained, the thermohydraulic efficiency reached its maximum value of 59.20% under 900 W/m2 at 0.14 kg/s. Conversely, the electrohydraulic efficiency attained the highest reading of 10.91% under 500 W/m2 at 0.13 kg/s. It was concluded that a higher flow rate reduces the friction coefficient while increasing the pressure drop. The thermohydraulic and electrohydraulic analyses emphasize the importance of assessing the friction coefficient and pressure drop to attain optimal performance. This study addresses the lack of research by presenting a new cooling approach that utilizes jet impingement. In addition, this study provides an understanding of the thermohydraulic and electrohydraulic performance of a RCFJI PV/T collector. [ABSTRACT FROM AUTHOR]

Jet impingement cooling enhances photovoltaic (PV) system efficiency by using high-speed fluid jets to reduce panel temperatures, improving performance and longevity. The effectiveness depends on factors like fluid flow rate, nozzle placement, and distance from the panel. While it boosts energy output, it may increase energy use for fluid circulation and add complexity to the system. This research explores a groundbreaking approach to enhancing the efficiency of bifacial photovoltaic thermal (BPVT) systems by integrating jet impingement technology. A novel design featuring a jet plate reflector is introduced, offering the dual benefit of cooling the PV panels while simultaneously reflecting light to optimize energy capture. The study comprehensively analyses the system’s performance, including energy output and a detailed techno-economic and environmental-economic evaluation. The modelling in this study was validated and reasonably consistent with experimental results. The system's output air temperature and thermal efficiency are 302.07–318.75 K and 33.83–62.28 %, respectively. The temperature and electrical efficiency range for PV systems are 304.39–339.54 K and 9.39–11.22 %. Reduced mass flow rate and increased solar irradiation are the most economically advantageous operating parameters for the proposed system, resulting in lower annual pumping costs and more significant annual energy gains for the system. CBR variations range from 0.1363 to 9.3445, with an average of 2. Additionally, by using BPVT with jet impingement to generate electricity rather than fossil fuels, it is possible to reduce annual carbon dioxide emissions by approximately 1.61 tons and save RM93.51 annually. In general, the proposed method should be used to minimize environmental pollution.

This study explored the impact of pulsation on the hydro-thermal behavior of an interrupted microchannel heat sink. A homogeneous blend of Al2O3-water was employed as the coolant. The investigation considers the influence of varying amplitude, pulsation frequency and Reynolds number. Findings indicate that using pulsating flow instead of steady flow substantially improved the thermal efficiency of the microchannel. The pulsating flow was observed to improve the Nusselt number by 17.43 %, 33.38 %, 50.66 %, 68.39 %, and 86.12 % at 5, 10, 15, 20, and 25 Hz, respectively compared to a steady flow. However, with heat transfer enhancement, there is an accompanying pressure drop caused by pulsating flow. Pressure drops increased with the pulsation frequency and reached a maximum value of 0.2695 MPa at f = 25 Hz and A = 0.8. Nevertheless, the performance evaluation criteria showed that although pulsating flow increases pressure drop, it offers significantly better overall thermal and hydraulic performance than steady flow. The PEC improved by 90.47 % at Re = 100, f = 25 Hz, and A = 0.2. The results demonstrate a conceivable technique to use pulsating flow to improve heat transfer performance in systems with high power density in confined spaces.

The automotive industry is increasingly focused on developing more energy-efficient and eco-friendly air-conditioning systems. In this context, CO2 microchannel gas coolers (MCGCs) have emerged as promising alternatives due to their low global warming potential (GWP) and environmental benefits. This paper explores the application of machine learning (ML) algorithms to predict the thermohydraulic performance of MCGCs in automotive air-conditioning systems. Using data generated from an experimentally validated numerical model, this study compares various ML techniques, including both linear and nonlinear regression models, to forecast key performance metrics such as refrigerant outlet temperature, pressure drop, and heat transfer rate. Spearman’s correlation was employed to develop performance maps, whereas the R2 and MSE metrics were used to evaluate the models’ predictive accuracy. The linear models gave around 70% forecasting accuracy for pressure drop across the gas cooler and 97% accuracy for refrigerant outlet temperature, whereas the nonlinear models achieved more accurate predictions, with an accuracy ranging from 71% to 99%. This implies that nonlinear regression generally performs better than linear regression models in assessing the overall thermohydraulic performance of microchannel gas coolers. This research brings forth new ideas on how ML methods can be applied to enhance efficiency and effectiveness in gas coolers, contributing to the development of more eco-friendly automotive air-conditioning systems.

Higher density heat flux is the major cause of damage to the electronic component; therefore, cooling such components are of the utmost importance to operate in a safe zone and to increase their life. For this purpose, Microchannel heat sinks (MHSs) are among the most practical methods for dissipating unwanted heat. In this regard, the novel lozenge-shaped pin-fins in the flow passage of the microchannel heat sink (MHS) have been designed and proposed to achieve higher cooling performance. Aspect ratios (λ = 0.30, 0.39, 0.52, 0.69, 1.00) of several lozenge-shaped pin-fins have been used into the design of MHS to investigate their impact on heat transmission and fluid flow characteristics. A three-dimensional model of MHS with a lozenge-shaped has been generated and simulated numerically in the following range of Reynolds numbers, starting from 100 to 900. Heat transmission and flow characteristics have been presented and discussed in detail. It has been found that introducing lozenge-shaped pin-fins in MHS has greatly improved cooling performance. The highest improvement in Nusselt number has been observed when aspect ratio (λ) of lozenge-shaped pin-fins was 1.00. The Nusselt number have been varied in the following ranges of 6.96–12.34, 6.97–12.72, 7.01–13.62, 7.09–14.43, and 7.12–15.26 at λ = 0.30, λ = 0.39, λ = 0.52, λ = 0.69, and λ = 1.0, respectively. In addition, a study of the thermohydraulic performance of the proposed lozenge-shaped pin-fins in the MHS found that this design is an effective means of lowering operating temperature. [ABSTRACT FROM AUTHOR]

Enhancing the thermal properties of the working fluid is a practical way to improve heat transfer performance. One of the suggested fluids for this purpose is nanofluids, which are suspensions of nanoparticles within a base fluid. Nanofluids have the potential to operate as a primary coolant or as an emergency coolant in a nuclear reactor. This paper investigates the thermal performance of a homogeneous hybrid nanofluid of Al 2 O 3 and TiO 2 in deionized water. The thermo-hydraulic performance of the nanofluid is analyzed in a high-pressure test loop capable of 25 bar pressure. The test section has an annular geometry, generating a cosine heat flux pattern. This flux pattern is representative of nuclear reactor cores. The experimental study is conducted to investigate the effects of nanoparticle concentration and Reynolds number on the heat transfer performance of nanofluids. The results show that increasing these two parameters significantly improved heat transfer. Specifically, raising the nanoparticle concentration from 0% to 1% leads to a reduction in surface temperature of 19% and 8% at Reynolds numbers of 825 and 4128, respectively. The calculated Nusselt numbers are compared with correlations from previous studies. Furthermore, an artificial neural network model is developed to predict heat transfer data for the studied system. The model consists of a single-layer feed-forward neural network trained with the stochastic gradient descent algorithm. To determine the optimal network, the number of neurons is optimized and evaluated based on the network's predictability. The neural network model demonstrates substantial improvements over previous experimental correlations (MAPE <2.5% and MSE <0.001). • Experimental analysis of homogeneous hybrid nanofluid in an annulus with cosine heat flux. • Experimental design to investigate the impact of nanoparticle volume fractions and Reynolds numbers. • Design of a single-layer feedforward neural network for predicting Nusselt number. • Comparison of different correlations for heat transfer of nanofluid. • Potential of utilizing nanofluids as a emergency core coolant. [ABSTRACT FROM AUTHOR]

Thermohydraulic characteristics of air as the working medium in a circular heated channel fitted with inlet obstruction (ribbed prism) at the inlet is carried out experimentally for transitional flow regime. The ribbed prism is fabricated using aluminum metal. Three non-dimensional parameters clearance ratio (C = 0.4, 0.5 and 0.6) and pitch ratio (e = 0.12, 0.15 and 0.16) were investigated. The Reynolds number (Nu) varied from 500 to 7036 to cover all the flow regimes. Experiments were conducted at two constant heat fluxes of 0.5 kW/m2 and 1 kW/m2. It was found that start and end of transitional flow regime was influenced by insertion of the inlet obstruction at the inlet of the test section. With placement of prism in the channel, the boundaries of transition changes when compared with the plain channel. It is observed that transition starts early and also end early to the transition limit of plain channel. Heat flux shows significant influence on the onset and termination of the transition. At higher heat flux the transition starts later and terminates later when compared with the lower heat flux conditions. For the case of C = 0.6 and e = 0.16, the transition begins Re = 1648 and ends at Re = 3387 for 1 kw/m2 heat flux. The transition of 0.5 kW/m2 of heat flux for C = 0.6 and e = 0.16 begins at Re = 1554 and ends at Re = 3321. Correlations were also developed for predicting the Nusselt number and friction factor and the results are useful to design solar thermal systems and heat exchangers.

Geothermal exploration concepts can be improved at an early stage of exploration by assessing the petrophysical rock properties of samples from surface outcrops. The results can be used to better evaluate the proposed geothermal resource and exploration strategies for the region. Our study provides fundamental knowledge on thermohydraulic rock properties to help identify the heat transfer mechanisms associated with geothermal resources in the extensional tectonic settings of the Ambilobe and Ambanja areas in North Madagascar. Thermostratigraphic units were defined according to the thermofacies concept. The geology of both areas is predominantly Quaternary volcanics (mainly basalt) and Permian–Triassic sediments (mainly shale and sandstone) overlying a faulted and fractured Proterozoic metamorphic basement of gneiss and amphibolite. Normal faults related to graben structures, along which hot springs occur, are characteristic of this extensional regime. Permian sandstone and mica schist have the highest porosities, with values up to 0.10–0.11. The matrix permeability of sedimentary and basement rock formations varies from less than 1.0 × 10–19 to 1.1 × 10–14 m2 (< 0.001 to 11 mD), while the average thermal conductivity is ~ 3.8 W m−1 K−1 and ~ 2.7 W m−1 K−1, respectively. Conductive heat transfer is expected for such low-permeability rocks, except where fractures form permeable conduits that promote forced convection driven by regional groundwater flow. Crustal-scale faults should be targeted for further geothermal exploration. [ABSTRACT FROM AUTHOR]

One of the challenges of future nuclear power is the development of safer and more efficient nuclear reactor designs. The AP1000 reactor based on the PWR concept of generation III + has several advantages, which can be summarized as: a modular construction, which facilitates its manufacture in series reducing the total construction time, simplification of the different systems, reduction of the initial capital investment and improvement of safety through the implementation of passive emergency systems. Being a novel design it is important to study the thermohydraulic behavior of the core applying the most modern tools. To determine the thermohydraulic behavior of a typical AP1000 fuel assembly, a computational model based on CFD was developed. A coupled neutronic-thermohydraulic calculation was performed, allowing to obtain the axial power distribution in the typical fuel assembly. The geometric model built used the certified dimensions for this type of installation that appear in the corresponding manuals. The thermohydraulic study used the CFD-based program ANSYS-CFX, considering an eighth of the fuel assembly. The neutronic calculation was performed with the program MCNPX version 2.6e. The work shows the results that illustrate the behavior of the temperature and the heat transfer in different zones of the fuel assembly. The results obtained agree with the data reported in the literature, which allowed the verification of the consistency of the developed model.

In order to study the safety aspects connected with the permanent increase of the maximum steady state power of the IPR-R1 Triga Reactor of the Nuclear Technology Development Center (CDTN), experimental measurements were done with the reactor operating at power levels of 265 kW and 105 kW, with the pool forced cooling system turned off. A number of parameters were measured in real-time such as fuel and water temperatures, radiation levels, reactivity, and influence of cooling system. Information on all aspects of reactor operation was displayed on the Data Acquisition System (DAS) shown the IPR-R1 online performance. The DAS was developed to monitor and record all operational parameters. Information displayed on the monitor was recorded on hard disk in a historical database. This paper summarizes the behavior of some operational parameters, and in particular, the evolution of the temperature in the fuel element centerline positioned in the core hottest location. The natural circulation test was performed to confirm the cooling capability of the natural convection in the IPR-R1 reactor. It was confirmed that the IPR-R1 has capability of long-term core cooling by natural circulation operating at 265 kW. The measured maximum fuel temperature of about 300 oC was lower than the operating limit of 550 oC. It has been proven that without cooling in the primary the gamma dose rate above reactor pool at high power levels was rather high.

Summary: The performance of the thermoelectric‐based waste heat recovery (WHR) system in an automobile greatly depends on the amount of heat extracted by the exhaust heat exchanger (EHE). In the present study, the thermohydraulic performance of the EHE having twisted ribs and the pressure drop across the entire heat exchanger have been experimentally investigated. The experiments were repeated for the various geometric parameters such as twist ratio (4‐8), angle of attack (30°‐90°), and pitch ratio (6‐10) on the Reynolds number within the range of 2300 to 25,000. The heat transport and fluid flow characteristics were compared with an internally smooth EHE using the thermohydraulic performance parameter. The maximum heat transfer rate was improved at 164.22%. However, the specification of the twisted rib for superior performance has been obtained at twist ratio of 4 and pitch ratio of 8 with 60° angle of attack. The highest thermohydraulic performance parameter value revealed as 1.93 at the same configuration. With the change in twist ratio, the pitch ratio, angle of attack, and the heat transfer rate increased by 39.52%, 60.85%, and 40.70%, respectively. Thus, the efficient heat transfer with the twisted rib would improve the extent of WHR in automobiles. [ABSTRACT FROM AUTHOR]

Highlights • This paper reports a full scale experimental study of liquid entrainment happens at ADS-4 branch of CAP1400. • 16 entrainment onset tests and 80 entrainment rate tests are finished. • Test data is compared with previous entrainment models, significant discrepancies are found and analyzed. • A new criterion to determine the onset of liquid entrainment is proposed. Abstract Liquid entrainment at the tee junction of hot leg to ADS-4 branch (fourth-stage Automatic Depressurization System) is a high priority safety related phenomenon in Westinghouse Advanced Passive pressurized water reactor (AP1000) and Chinese Advanced Passive pressurized water reactor (CAP1400). Previous studies are mainly carried out on reduced scale experimental test facilities. To offer a better understanding of the liquid entrainment phenomenon at tee junction and evaluate the applicability of entrainment models, a full scale test facility is designed and fabricated. The maximum air and water flowrates are 12 kg/s and 150 kg/s respectively. 16 onset of liquid entrainment tests and 80 entrainment rate tests are carried out on this test facility. Test data is compared with previous entrainment models. Significant differences are founded. This means the applicability of liquid entrainment models in safety analysis code is questionable. Based on the flow regime transition criterion in horizontal pipe, a new onset of liquid entrainment model is proposed. The agreement of the new model to test data is better than previous models. [ABSTRACT FROM AUTHOR]

Enhancement of heat transfer in the solar air heater ducts can be achieved by breaking laminar sub-layer near the absorbing surface and can be efficiently done by employing ribs as roughness elements. However, this gain is accomplished at the expense of increase in pressure drop. This paper presents the detailed review of various investigations made on artificial roughness geometries summarizing their outcomes. Attempt have been made to study the effect of various influencing roughness and flow parameters on the thermal and hydraulic performance of solar air heater through the flow visualization. [ABSTRACT FROM AUTHOR]

This paper describes the computational fluid dynamics (CFD) analysis and validation works from the previous experimental study on the natural convection driven by outer surface cooling in the presence of density stratification consisting of air and helium (as a mimic gas of hydrogen). The experiment was conducted in the Containment InteGral effects Measurement Apparatus (CIGMA) facility at Japan Atomic Energy Agency (JAEA). CIGMA vessel is a large cylindrical stainless steel with an inner diameter of the main cylindrical part 2.5 m and an overall height of 11 m. The mass fraction proportion of helium in the whole vessel was 11% and the helium molar fraction at the top vessel was 48%. Two experiments were performed and the numerical simulation was carried out to analyze the detailed effect of the cooling region on the erosion of the helium stratification layer. First test was named CCLP30 or case 1 and second test was named CCPL34 or case 2. The main difference between case 1 and case 2 was the cooling area of case 1 was narrower than case 2. In case 1, cooling area was only located at the one-fourth of outer vessel. Whereas, in case 2, cooling area was located at one-half of outer vessel. The temporal and spatial evolution of the helium concentration and the gas temperature inside the containment vessel was predicted and validated against the experimental data. The results indicated that the numerical predictions fairly agreed with the experimental data. However, the predicted erosion rate showed discrepancies compare with the experimental data. The relative errors time required for the complete dissolution of the helium gas were within 15%. In addition, two stratification behaviors that depend on the cooling location were presented and discussed. The CFD simulation confirmed that an upper head cooling caused two counter-rotating vortexes in the helium-rich zone. Meanwhile, the upper half body cooling caused two counter-rotating vortexes in the helium-poor zone. These findings are important to understand the mechanism of the density stratification process driven by natural convection in the containment vessel. [Display omitted] • This paper describes a numerical investigation of natural convection driven by outer cooling in the presence of density stratification consisting of an air-helium gas mixture. • We investigated natural convection behavior in density stratification using RANS analysis, in which we focused on the relative location between the outer cooling and stratification. • The numerical result indicated that two counter-rotating vortexes established in both upper head cooling and upper half of body cooling. [ABSTRACT FROM AUTHOR]

The effects of impinging air jet on the thermo-electro-hydraulic performance of a bifacial PVT with different packing factors are entirely unclear. Here, we have proposed a dual-functional jet plate reflectors are introduced to induce jet air cooling and increase the light absorption at the rear part of the bifacial PV module. The effects of jet plate reflectors with different configurations on the system's performance are investigated and studied. The simulation results were verified and validated with the experimental findings. Increasing the distance between jet holes reduces the interference and enhances the heat transfer, which led to higher friction and greater pumping power. Net energy gain is the key to calculate hydraulic efficiency, by subtracting the pumping power from the energy output. Therefore, the system's best performance can be explained by the lowest Re to generate max efficiencies. Jet impingement bifacial photovoltaic thermal (JIBPVT) with 36 jet-holes has the greatest jet spacing between the jet holes and optimum performance. The maximum thermal energy gain and electrical energy produced were achieved at lower critical values of Re, which are 9929 and 5667, respectively. JIBPVT has the optimum thermal, electro, and thermo-electro-hydraulic efficiencies, with 57.3%, 10.36%, and 83.93%, respectively. • A novel design of jet impingement bifacial photovoltaic thermal (JIBPVT) solar air collector was presented. • Dual-fuctional jet plate reflectors with different geometric configurations were introduced. • A one-dimensional heat flow analytical model in steady-state was developed for JIBPVT solar air collector. • The simulation results were validated with experimental results and a good agreement was shown between them. • Thermo-electro-hydraulic analysis, which taken friction factor, pressure drop, and pumping power were discussed. [ABSTRACT FROM AUTHOR]

• Thermohydraulical and electrical analysis of JT-60SA TFC quench test in CTF. • JT-60SA TFC quench model development with SuperMagnet and STREAM codes. • STREAM upgrade to CICC cooling process with analytical quench propagation velocity. • Benchmark of numerical and analytical tools. • Impacts estimation of JT-60SA TFC quench event in tokamak configuration. In the framework of JT-60SA Tokamak commissioning (Japan, 2021), all coils have to be cooled with supercritical helium forced-flow at the temperature of 4.5 K in order to reach superconducting state before energization. An important issue is to predict the Joule energy dissipated in Cable-In-Conduit Conductors (CICC) and the maximal temperature reached in case of an incidental quench occurrence. Therefore, quench simulations were performed on the Toroidal Field Coil (TFC) with the STREAM (Superconductor Thermal hydraulic and Resistive Electrical Analytical Model) code and with the SuperMagnet code (CryoSoft), coupling THEA (thermal hydraulic and electrical 1-D CICC model) and Flower (thermal hydraulic network model). The quench event was simulated for one TFC at nominal conditions of tokamak operation. External energy deposition over each pancake's first turn of the coil at the peak magnetic field location was applied for initiating the resistive transition. This way, the computed Joule energy dissipated by one TFC is conservatively evaluated to be 5.65 MJ. The Joule energy dissipation depends strongly on quench initiation conditions and on the number of fully and rapidly quenched pancakes (maximal quench propagation velocity of 19.5 m/s). Some further analyses were performed on the acceptance quench test realized at the Cold Test Facility (CEA Saclay, 2018) on TFC02. The different calculation results (helium temperature, mass flow rate in upstream and downstream manifolds, normal length propagation) are presented in the following study and are consistent with the measurements. This analysis brings information on the limits and the ability of STREAM code to model quench behaviour in CICC coils cooled by forced flow of supercritical helium. This tool could be useful for tokamak magnets protection during quench event and safe operation, notably thanks to its fast computing time. [ABSTRACT FROM AUTHOR]

A thermo-hydraulic analysis of high-speed free surface Li flow over a concave plate (IFMIF geometry) is performed. Simulations are done for bulk velocities between 10 and 20 m/s using ANSYS Fluent. A pre-computed heat source was imposed at the center of the curved section to simulate the interaction of a dual deuteron beam with the Li jet. LES and k - ϵ models were used for turbulence modeling and Volume of Fluid and Level Set methods were used to model the free surface flow. Results reported are the variation of temperature, pressure and velocities across the Li jet at various locations along the curved region. Safety margins before Li starts boiling are also predicted. All cases predicted smooth surfaces without any waves. [ABSTRACT FROM AUTHOR]

Abstract: The International Fusion Materials Irradiation Facility (IFMIF) is designated to generate a materials irradiation database for the future fusion reactors. The High Flux Test Module (HFTM) is located behind the lithium target where a structural damage rate of more than 20dpa/fpy in steel specimen will be achieved in a volume of about 0.5l. This paper concerns the thermo-hydraulic simulations of the HFTM with Ansys-CFX. The simulation domain consists of the whole HFTM with short fluid inlet and outlet sections. The turbulence models were assessed by comparing the simulations with in-house annular channel experiments. The flow distributions and heat transfer characteristics among various HFTM sub-channels are the main focuses of this study. [Copyright &y& Elsevier]

Abstract: Local Power Range Monitor, LPRM, spiking has always been treated as a defect in the detector or in the electronic components that adapt the core’s power signal. Until now, the only studies have been based on the installation of condensers, which is a purely reactive approach, or in other cases on seeking the root cause in the existence of tin whiskers, which is very difficult to analyse from the forensic perspective. Detailed investigations at a boiling water reactor power plant (BWR6) have studied the occurrence of spiking, as well as the power plant’s conditions upon the occurrence of power spikes. This analysis leads to the conclusion that spiking takes place under certain conditions affecting the core and recirculation loop flow. The equations that control spiking will be expanded based on this assertion. Finally, it has been checked that spiking has no connection with fuel failures, since the locations of the LPRMs with spiking do not match the locations of the failed elements. [Copyright &y& Elsevier]

Abstract: The aim of the present work is to choose an optimal use of CFD codes for thermohydraulic calculation of the helium cooled fusion reactor components, such as divertor module, test blanket module and International Fusion Materials Irradiation Facility (IFMIF) test modules. In spite of common features (intense heat flux, nuclear heating of the structure, helium-cooling), all these components have different boundary conditions, such as helium temperature, pressure and heating rate and different geometries. It is the reason for the appearance of some effects in the flow influencing significantly the heat transfer. A number of turbulence models offered by the commercial STAR-CD code were tested on the experiments carried out in the Forschungszentrum Karlsruhe (FZK) and on the experimental data from the scientific publications. Results of different turbulence models are compared and analysed. For geometrically simple channel flows with significant gas property variation low-Re number k–ɛ models with damping functions give more accurate results and are more appropriate for the conditions of the IFMIF HFTM. The heat transfer in regions with flow impingement is well predicted by turbulence models, which include different limiters in the turbulence production. Most reliable turbulence models were chosen for the thermohydraulic analysis. [Copyright &y& Elsevier]

• A graphical tool for the selection of turbulence promoters is introduced. • Selection approach based on thermal and hydraulic length. • Highly performing devices are readily identified. • Analysis extended to the retrofit of existing units. This paper presents an alternative approach for the selection of the most suitable turbulence promoter for the intensification of heat transfer in tubular heat exchangers. The approach uses the thermal and hydraulic lengths that are determined based on the two main design objectives in a heat exchanger, the heat duty and the pressure drop. Exchanger dimension in the form of plots of the exchanger length are produced to identify the device that results in the smaller equipment size within the constraints imposed by the pressure drop. The length plots are produced for various types of turbulence promoters under fixed design specifications such as heat duty, pressure drop, mass flow rate and tube diameter. The results indicate that from a set of 25 different types of turbulence promoters studied, those that exhibit the largest heat transfer enhancement with the lowest pressure drop are the V-cut twisted tape, the square-cut twisted tape, and the straight tape with center wings. The benefits of the use of heat transfer enhancement on the stream that controls heat transfer on a practical heat exchanger design is analysed on a case study. [ABSTRACT FROM AUTHOR]