High Heat Load Research Articles

Structural damage in graphene oxide coatings onto Nb substrates upon laser irradiation

In this work graphene oxide (GO) coatings were obtained on Nb substrates by electrophoretic deposition (EPD), using a ramp of stepped potential and variable deposition time, to evaluate the feasibility as a protective coating against the exposition to a 20 W Yb laser (1070 nm). Laser irradiation constitutes a first approximation to the potential damage by local high heat loads that could occur in a Tokamak-type fusion reactor. GO coatings can act as the first barrier against exposure to the fusion reactor plasma, but the coating may experience local high heat loads and simultaneous exposure to energetic particles. The GO/Nb coatings were irradiated with different laser power-frequency settings. With X-ray photoelectron spectroscopy, the bonding evolution of the coatings was followed for each deposition time. Scanning electron microscopy was used to evaluate the coating morphology before and after laser irradiation, whereas Raman spectroscopy was used to evaluate the structural evolution of GO coatings, crystallinity , and disorder in the graphene oxide. An increase of the crystallite size due to sp 2 restoration was observed for the films prepared up to 10 s/V. Atomic force microscopy was used to study the film morphology and to estimate the film thickness by comparing the z-offset between the substrate and coating topography images. Film thickness reduces from ca. 280 nm to 100 nm with the increase in the time at each voltage step. Coating tolerance against laser-induced damage was observed up to 34% of the full laser power, where the coating was damaged and local metal melting was observed. The coating damage occurs between 4.9 × 10 8 MW/m 2 and 2.5 × 10 9 MW/m 2 and higher power levels triggered the occurrence of melting in the metallic substrate. The reduction in laser damage is attributed to the enhanced thermal dissipation by the sp 2 dominion as the crystallite size increases. GO coatings prepared by electrophoresis are shown to be promising to protect nuclear components against damage for high heat loads. • Adherent and stable GO coatings were obtained on Nb substrates by novel EPD process. • GO coatings were irradiated with high-power laser for structural damage evaluation. • Damage threshold for GO coating is 4.9 × 10 8 MW/m 2 and for Nb substrate 2.5 × 10 9 MW/m 2 . • Reduction of GO and sp 2 domain restoration after EPD enhance resistance to radiation. • GO coatings are feasible as plasma facing components in nuclear fusion reactors.

Studies on Heat Transfer Coefficient of a Circular Tube With Twisted Tape Insert for High Heat Flux Cooling Applications

Herein, the heat-transfer characteristics of the subcooled flow boiling of swirl tubes are evaluated experimentally under one-side high heat load conditions. As the twist ratio of the tape decreased and the flow rate increased, the forced convective heat transfer was enhanced; thus, the single-phase heat transfer was enhanced, and the onset of nucleate boiling (ONB) heat flux increased. As the degree of subcooling increased, the ONB heat flux increased because of the faster condensation rate. As the pressure increased, the ONB heat flux increased, and the critical heat flux increased, due to the suppression of boiling and the decrease in the bubble size. The authors analyzed the heat transfer characteristics of the one-side heated swirl tube in the single-phase regime, the partially developed nucleate boiling (PDB) regime, and the fully developed nucleate (FDB) boiling regime. And the prediction performance of the existing heat-transfer correlations developed for application to each regime was evaluated. The PDB correlations showed a mean absolute error rate (MAE) of approximately 30%. However, the existing FDB correlations a high error rate (MAE higher than 48%) at a high heat flux of several MW/M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> outside the developed experimental range. Therefore, we develop a new swirl tube FDB heat-transfer correlation that can also be used in the development of a swirl tube flow boiling map using the Python code grafted with the artificial intelligence (AI) regression method.

Critical Heat Flux Analysis With Single-Side Heated Swirl Tube Under Subcooled Flow Boiling Conditions

Critical heat flux (CHF) is regarded as one of the major problems in cooling system design. Specifically, because the tokamak is loaded with heat flux of several megawatts per square meter, carefully considering the CHF is crucial. This study analyzes the subcooled flow boiling CHF of the swirl tube under one-side high-heat load condition. The CHF parametric analysis results indicate that smaller swirl tape twist ratios yield higher swirl flows. As the subcooling increases, the CHF increases because the vapor inside the channel condensates more rapidly due to the lower bulk temperature. And the increase of the mass flow rate also increases the CHF because it enhances the forced convection heat-transfer performance. However, the CHF slightly decreases as the latent heat decreases with the increase in pressure. The assessment of existing CHF subcooled flow boiling indicates that the formulated correlations based on the smooth tube mainly tend to yield under-predicted results. However, most of the correlations developed according to the swirl tube tend to over-predict. Among these, the Nariai and Inasaka swirl CHF correlation has the lowest error rate; nevertheless, it tends to slightly under-predict results because of the difference between uniform and one-side heating. Accordingly, a new modified Nariai and Inasaka correlation is formulated using a Python code and artificial intelligence technology to reflect the one-side heating effect.

Experimental investigations on indirect contact type liquid desiccant cooling systems for high latent heat load application

Heat driven sorption technologies are promising alternatives to traditional vapour compression based systems for comfort cooling. High latent heat load applications and improved indoor air quality are best accommodated by the various sorption technologies available and desiccant-based cooling systems. Liquid desiccant-based systems are preferred over solid desiccant-based systems due to lower pressure drop, the possibility of continuous operation, solar energy for regeneration, and the ease of storage of regenerated desiccant solution. This paper investigates the experimental performance of indirect contact type liquid desiccant cooling systems for applications involving a high latent heat load. An experimental test rig includes a dehumidifier, regenerator, and heat exchanger, all been developed, fabricated and connected to work as one unit. The dehumidifier and regenerator transfer the heat and mass from liquid desiccant to the air membrane making the arrangement an indirect contact type of heat exchanger. Lithium Chloride solution is used as a desiccant solution in experiments, and Polyvinylidene Fluoride is used as a membrane material. The effect on dehumidifier performance parameters like rate of moisture removal, sensible heat effectiveness, and latent heat effectiveness is studied for varying inlet air parameters as well as for various liquid desiccant operating parameters. The inlet air specific humidity ranges from 10 to 13 g/kg da, and the inlet air flow rate varies from 2 to 4.5 kg/hr. The inlet desiccant temperature supplied at 24–32 0C with desiccant concentration varied 30–42%, and the desiccant solution mass flow rate is supplied in the range of 3–11 kg/h. Various dehumidifier performance parameters like rate of moisture removed, latent heat effectiveness and sensible heat effectiveness are discussed. Based on the experimentation, utilizing the optimum values of inlet air parameters or optimum values of desiccant solution parameters has been recommended to achieve the cooling system's highest possible latent heat effectiveness.

Study on onset of nucleate boiling with screw tube for fusion reactor application

The onset of nucleate boiling (ONB) is the point at which the heat transfer mechanism in fluids changes and is one of the thermo-hydraulic factors that must be considered when establishing a cooling system operation strategy. Because the high heat flux of several MW m−2, which is loaded within a tokamak, is applied under a one-side heating condition, it is necessary to determine a correlative relation that can predict ONB under special heating conditions. In this study, the ONB of a one-side-heated screw tube was experimentally analyzed via a subcooled flow boiling experiment. The helical nut structure of the screw tube flow path wall allows for improved heat transfer performance relative to plain tubes, providing a screw tube with a 53.98% higher ONB than a plain tube. The effects of the system parameters on the ONB heat flux were analyzed based on the changes in the heat transfer mechanism, with the results indicating that the flow rate and degree of subcooling are proportional to the ONB heat flux because increasing these factors improves the forced convection heat transfer and increases the condensation rate, respectively. However, it was observed that the liquid surface tension and latent heat decrease as the pressure increases, leading to a decrease in the ONB heat flux. An evaluation of the predictive performance of existing ONB correlations revealed that most have high error rates because they were developed based on ONB experiments on micro-channels or plain tubes and not under one-side high heat load conditions. To address this, we used dimensional analysis based on Python code to develop new ONB correlations that reflect the influence of system parameters.

High power experiment and heat load evaluation of transmission line for the ECH/CD system in JT-60SA

Temperature rise of the waveguide transmission line for high-power long-pulse ECH/CD system has been evaluated experimentally using the dummy load transmission line in JT-60SA. It has been demonstrated that the waveguide components with the inner diameter of 60.3 mm are applicable for 1 MW/100 s transmission at 110/138 GHz required in JT-60SA. A newly developed pre-load installed in front of the dummy load reduced the temperature rise of the waveguide due to the reflection from the dummy load. With this pre-load, the temperature rise distribution in the 37 m-long test transmission line was measured to simulate the real transmission line condition for tokamak experiment. As a result of the high-power experiments, it has been clarified that the temperature of the waveguides close to miter-bends could be increased by approximately 120 K for 1 MW/100 s operation at 110 GHz, in the worst case, and it is marginal for the stable operation with the waveguides made of aluminum alloy. The heat loads on the waveguides have been evaluated as 23 kW/m2 for the worst case between miter bends, 12–23 kW/m2 within 4 m from miter bend and 4–12 kW/m2 for waveguide far from miter bends. The evaluated heat loads will be taken into account for the final design of the TL components and cooling for the JT-60SA ECH/CD system.

Impact of design parameters of diffuse ceiling ventilation systems on indoor air quality in school classrooms: a numerical assessment

Indoor air quality directly impacts an individual’s productivity and health condition in office buildings, hospitals, schools, and residential buildings. Diffuse ceiling systems have been used widely in classrooms at schools that have high heat loads. In this regard, this study investigated the role of diffuse ceiling design parameters, including active diffuse panels’ configuration and contamination locations, on indoor air quality in a classroom. The spread of airborne infectious diseases was simulated using computational fluid dynamics techniques. The results revealed that the central configuration of diffuse ceiling panels had the minimum spread of contaminations in the classroom compared to the dispersed configuration.

Low activity levels are an adaptation to desert-living in the Grey Falcon, an endotherm that specializes in pursuing highly mobile prey.

Endothermic animals that live permanently in hot deserts must avoid harmful hyperthermia when their body temperature increases from heat gained through external and internal sources. This is true particularly for endotherms that are exclusively diurnal. We investigated the Grey Falcon (Falco hypoleucos), a predatory Australian endemic restricted to the hot arid/semi-arid zone. To understand how this species' entire population persists exclusively and permanently in this extreme environment we examined its activity levels and compared these with equivalent variables from the Peregrine Falcon (F. peregrinus), a cosmopolitan species that inhabits similar environments without being restricted to them. Further, we compared, across a selected group of Falco species, specific plumage characteristics (measured on museum specimens) that we anticipated would enhance the Grey Falcons' ability to cope with high heat loads. We found no morphological or physiological characteristics that would allow them to cope with heat better than other birds, but the chicks seem to have unusually high thermal tolerances. Grey Falcons do, however, possess a suite of unusual behavioural adaptations that, as we propose, enable them to cope with climatic extremes in arid environments. Specifically, throughout their lives Grey Falcons keep activity levels and thus physical exertion low. This behaviour contrasts strikingly with that of the Peregrine Falcon, which also actively hunts birds in flight. Keeping activity levels low is expected to minimize endogenous heat production and thus ease the Grey Falcon's thermoregulation during periods of high heat load. These birds may rely on low levels of relative humidity for efficient evaporative cooling, and this may explain their absolute restriction to hot arid/semi-arid zones.

Study heat exchange in porous structures

This paper shows the problem with heat exchange depending on units of thermal power plant equipment. The type of structures is determined and the heat flow for different pressures is proposed. Studies are developed for the condition of the heat exchange surface. Devices with porous coatings eliminate the development of cracks in the components and units of TPP equipment have been suggested. The research is applicable to gas turbine units of TPP. Comparable capillary-porous and flow systems have high reliability, but the former allowed the reduction of coolant consumption dozens up to 80 times. The results show that at higher heat loads it is suitable to use in porous surfaces to control the cooling surface. Evaluation of capillary-porous structures has shown their advantages over traditional cooling systems.

Fusion energy: technological challenges

This paper presents an overview of the main technological challenges of magnetic confinement fusion. Many of the challenges are being addressed in the context of the ITER construction and exploitation. Specifically, the demonstration of high-fusion gain regimes of operation will also provide a test of the technological solutions presently foreseen for the management of high heat and particle loads and the integration of the main technologies of a fusion power plant. In preparation of DEMO, reliable solutions for the breeding blanket and neutron resistant materials have to be developed.

Study of the heat transfer performance of a loop heat pipe with aluminum wick

This study used aluminum powder as a raw material to fabricate a wick for loop heat pipes by the powder metallurgy method and took advantage of the excellent corrosion resistance, low density and low cost of aluminum. The average pore diameter, porosity and permeability of the aluminum wicks were 9 ?m, 47.65%, and 2.1 ? 10?13 m?2, respectively. Then, to verify the feasibility of the aluminum wick, it was installed into a loop heat pipe to test the heat transfer performance. The experimental results showed that the loop heat pipe could transport a heating load of 130 W with a thermal resistance of 0.04 K/W under horizontal condition. A steady-state loop heat pipe mathematical model was developed, and the numerical results were compared with the experimental data. The results show that the model data are consistent with the experimental data, which means that Al wicks are suitable for use in the case of a high heating load and light weight.

Effect of heat load on pneumatic temperature control characteristics of a pressure-controlled loop heat pipe

The effect of the supplied heat load on the operating characteristics of the pneumatic temperature control technique was systematically investigated. A pressure-controlled loop heat pipe employing water as a working fluid was designed and constructed to provide a unique thermohydraulic linkage between temperature and pressure. The temperature of the high-speed vapor was precisely controlled by using helium (control gas) to actively control the compensation chamber pressure; the stability of the pneumatically controlled temperature was approximately 0.01 °C regardless of the heat load. Stable stepwise temperature increase was attained below a critical pressure step that rose with increasing heat load. This behavior implied that a stable range of pneumatic temperature control became larger with increasing heat load. In addition, the maximum pressurization rate for rapid, stable, and unlimited temperature rise increased with increasing heat load. The uniformity of the controlled temperature field was less than approximately 0.2 °C over 25 cm; effects of the heat load were insignificant at all tested conditions. Overall, pneumatic temperature control over extended pressure and temperature ranges was attained at higher heat loads with insignificant effects of the heat load on stability and uniformity.

Experimental Investigation on Filtration and Cooling Effect of Kitchen Hood Ventilation System from Water-Mist Recirculation Spray: Water-Mist Spray Cycle

A Water-mist spray system in several heavy-duty kitchen hood canopies is installed to efficiently control the high heat loads and grease emissions produced from the cooking process and for safety purposes. The main purpose of this study is to reduce water consumption by introducing the water-mist recirculation system to replace the current method water-mist system since it is working as water loss. A standard ASTM 2519 and UL 1046 full-scaled experiment is developed in the laboratory. An existing Halton Europe/Asian water-mist operating system is adopted in this study. Twelve (12) cycles (at 24 hours of water-mist activation) have been studied to determine the maximum water-mist activation cycle. The data are collected at two (2) hours water-mist activation at every water-mist recirculation cycle. The water-mist spray fluids viscosity is 0.7 cP from fresh water until the 4th cycle (8 hours water-mist spray) and increase 14.29% (0.8 cP) at the 5th cycle to the 12th cycle. On average, the difference in gas emissions percentage for CO concentration between fresh water until the 4th cycle is 10.81 – 18.92% while the CO2 concentration is 12.33 – 18.22%. On average, the difference in cooling effects percentage for ducting temperature between fresh water until the 4th cycle is 5.55% while the hood temperature is 2.33%. From the study, the water-mist recirculation system could save up to 611,667 litres per year and 466,798.5 litres per year water for all U.S, European, and Asian kitchen hood designs per hood length. By adopting the new water-mist recirculation system to the current water-mist kitchen hood, the water operational cost for water successfully reduced to RM 4,889.63 per year and RM 6,977.86 per year for U.S design and European or Asian design per hood length respectively. The water-mist recirculation system has great potential to improve the current water-mist system for the commercial kitchen hood.

The Role of Buoyancy Induced Instability in Transpirational Cooling Applications

Transpirational cooling is an effective thermal protection method in hypersonic vehicles. In order to properly manage the high heat load, an understanding of the convective flow regimes as well as the thermophysical properties of the working fluid are required. Often, the vehicle’s fuel is re-purposed as the coolant or working fluid that is passed through the porous media. If the geometry is such that the coolant is heated from below, buoyancy-induced instability can ensue resulting in a mixed convection phenomena. Transpirational cooling applications require a unique analysis which combines a Darcy–Forchheimer relationship for the momentum relation, a flowing base state which introduces non-negligible convective terms for the energy equation, and a novel consideration of a cubic density dependence on temperature. This latter feature is justified by fitting thermodynamic data for typical transpirational cooling conditions. A base state solution is provided and the onset of instability is investigated using linear stability analysis. The governing equations are solved utilizing multiple methods, comparing results from a combination of analytical solutions, finite difference, power series, and Chebyshev methods. Results demonstrate excellent consistency in predictions across these methods and indicate that including non-linear density effects promote a stabilizing effect. Finally, the effect of varying the net through-flow in the porous media is investigated.

Experimental Analysis of Control Methods in Solar Water Heating Systems

This paper focuses on an analysis of selected control methods in solar heating systems. Proportional, ON-OFF, and new proposed IPC control methods were tested. Experimental tests were conducted under natural conditions using the author’s method of clustering measurement days. In the form of thermal energy gains in the storage tanks, the results for all tested control methods are presented. The ON-OFF control method is suitable for low variability of solar radiation conditions but is ineffective under dynamic solar radiation conditions. The proportional controllers collect thermal energy under high variability solar radiation effectively, but they tend to cause thermal drifts from the system under high heat load. The proposed IPC control method prevents the waste of heat energy and makes more efficient use of the high and dynamic solar radiation. In conclusion, energy gains depend more on the level of solar radiation and less on its variability. However, the variability of solar radiation makes control in solar systems more challenging, and it is one of the factors that should determine the control strategy. The novelty of this work is based on an extension of the control algorithm by adding the temperature at the entry and exit of the solar coil. This makes it possible to eliminate thermal drift and observe the intensity of heat transfer to the water in the tank.

Predicting the onset of nucleate boiling heat flux of one-side heated flat heat sink in sub-cooled flow conditions for fusion divertor cooling

For the cooling system of the future, nuclear fusion tokamak, to operate stably and continuously, it is important to identify potential hazards that may occur in the system in advance. Among the various hazards associated with the nuclear fusion tokamak, the onset of nucleate boiling (ONB) is a point at which the heat-transfer mechanism changes dramatically and is a crucial factor that must be addressed. In particular, the equipment inside the tokamak is loaded with a heat flux of several MW m−2 under single-side heating conditions, and it is important to predict the ONB under these special heating conditions. Therefore, in this study, the ONB of a flat heat sink was experimentally investigated under highly subcooled flow conditions. Based on the physical understanding of the thermo-hydraulic aspect of the ONB, the wall temperature gradient change point, which is mainly used in the subcooled flow condition, was selected as the ONB detection criterion. Trends in the ONB heat flux change were analyzed as representative system parameters that can be tuned in the cooling system, such as subcooling, mass flow rate, and pressure. In addition, the ONB correlations developed in the previous studies were evaluated for predicting the performance under one-side high heat load conditions. However, the large difference in the experimental conditions (range of system parameters and heating conditions) and the fact that the influence of system parameters was not reflected in the correlation resulted in high error rates. Therefore, the ONB correlation that can be used in the tokamak heat flux condition was newly developed through a dimensional analysis that can effectively reflect the influences in the correlation through dimensionless numbers. The developed correlation can be of great help in designing a diverter or blanket cooling system and establishing an operational strategy.

Assessment of the Possibility of Reducing the Thermal Load in the Barn by using Mechanical Ventilation

Abstract The aim of this work is to evaluate possibility of reducing the heat stress of milking cows via climatic indices and the influence of air flow velocity in the object with milking cows using the cross-section method. For the purposes of evaluation, there was selected a four-row housing facility for 160 milking cows with natural ventilation; for the summer period, natural ventilation was supplemented with mechanical ventilation (2877 m3·h−1 per cow). Measurements were conducted in the network created with 12 measuring points across the barn width, repeated in five cross-sections A, B, C, D and E, followed by further measurements in the longitudinal direction performed always in a row of 22 points placed in resting zones along the air flow direction. Considering the state of potentially high heat load with THI &gt;78, it was observed that, according to ETIC, without employing the fans, ETIC in AOZ was higher than nAOZ, ETICAOZ = 25.34 ±0.42 vs ETICnOAZ = 24.51 ±0.44 (p &lt;0.05). After activation of fans above lying area, ETIC in AOZ was lower than nAOZ, ETICAOZ = 23.40 ±0.61 vs ETICnAOZ = 23.68 ±0.60, which was not validated in evaluation of THI. Even though the limiting value of very high heat stress ETIC = 25 was not exceeded after activation of fans, decreasing of heat stress in rest zones did not reach recommended value ETIC = 20. A more significant improvement was validated in ETIC evaluation with measurements in longitudinal direction in the lying area – there was confirmed dominant influence of air flow speed. Heat load decreasing was influenced by speed and distribution of air in AOZ, both overall and local air exchanges in AOZ with ACHv &gt;100 h−1, and barn length.

The heat flux and temperature distribution of W fuzz layers under fusion-relevant He/D ion irradiations

The thermal diffusion of nanostructured W fuzz layers formed over W divertor targets due to fusion-relevant He + irradiations remain unclear so far. By analyzing the collision process of energetic He + and D + ions in the fuzz layers, we have calculated the temperature distribution and heat flux of fuzz layers under low-energy (10–200 eV) and high-flux (10 22 –10 25 /m 2 ⋅s) He + /D + irradiations. Both the heat flux of fuzz layers and the temperature difference ( Δ T ) between the top and bottom of fuzz layers are determined by the radius of W nanofibers, the thickness of fuzz layers, and the heat load over W targets. Our simulation predicts that under fusion-relevant He + /D + irradiations at the energy of < 100 eV and the flux of < 1.0 × 10 24 /m 2 ⋅s, Δ T is lower than 35 K when the heat load over the divertor varies in the range of < 10 MW/m 2 . Under the fusion-relevant He + /D + irradiations, the heat flux of nanostructured fuzz layers is about 13–19% of the extremely high heat load over the W targets, indicating that the fuzz layers over W divertor targets can be very important for decreasing the extremely high heat load, such as type – I edge localized modes in the fusion device.

Experimental study of thermal limits with one-side heated smooth channel for plasma facing component safety

In order to stably operate the equipment inside the tokamak, which is loaded with a heat flux of several MW m−2 under the one-side heating condition, it is necessary to thoroughly prepare for various thermal engineering limits that may occur under the high heat flux load condition. In this study, we have experimentally explored critical heat flux (CHF) and onset of flow instability (OFI), which are considered potential threats in a DEMO fusion power plant. Specifically, the effect of system parameters on CHF was investigated. The results indicate that with an increase in subcooling and mass flux, the CHF increased, as it induced a faster bubble condensation near the CHF. As the system pressure increased, the CHF also increased. This is because the bubble size reduction effect was dominant in the pressure range of 1–10 bar. Most of the existing CHF correlations could evaluate the CHF with reasonable accuracy of within 25%; especially, the Boscary CHF correlation yielded the highest accuracy with an average error of 12%. Similar to CHF, OFI, which is a measure of the sudden fluctuations in the system pressure caused by a large amount of vapor generated due to the high heat flux, tended to increase as the subcooling, mass flow rate, and system pressure increased. Most of the existing OFI correlations yielded large error rates (more than 135%) as these correlations were primarily developed for micro-channels. Therefore, in this study, a new OFI correlation was developed using a Python code, in combination with an artificial intelligence (AI) regression method. The developed correlation can be used in the cooling system design of tokamaks, which involve a high-heat load condition on one-side of the reactor.

Enhanced single-phase heat transfer performance via vortex secondary flow in hypervapotron configuration

As the hypervapotron (HV) heat sink is used to cool many areas inside the fusion tokamak, it is essential to understand its heat transfer performance to calculate the thermal efficiency of the power generation system. Therefore, in this study, the single-phase (SP) heat transfer performance of HV heat sink was evaluated through sub-cooled flow boiling experiments under one-side high-heat load conditions. When vapor is generated inside the heat sink, flow instability and a potential risk of reaching the critical heat flux are created. Therefore, in commercial power plants, cooling systems tend to operate in the SP regime. System parameters that can be adjusted in the power generation system include the system pressure, mass flow rate, and subcooling, and the effect of these three parameters on the heat transfer performance in the SP regime was analyzed. It was experimentally observed that the mass flow rate was the most influential variable. The prediction performance of the SP forced convection heat transfer correlations of the existing conventiaonl channel were evaluated. The results revealed that they tended to under-predict the heat transfer performance of the HV heat sink. In addition, the same trends were found when the forced convection heat transfer correlation of the curved channel was evaluated. The reasons for the former and the latter are that the heat transfer enhancement effect by the vortex flow occurring between the fins of the HV heat sink is not reflected in the correlations, and the vortex effect of the HV heat sink is not expressed as a variable. Therefore, a new vortex forced convection heat transfer correlation was developed through the newly defined Dean number of the HV heat sink. The developed correlation recorded an average error rate of 0.48%.