Thermal Sink Research Articles

Impacts of thermal source and sink on magnetoconvection in an annular geometry: A numerical analysis.

The current work analyzes the collective effects of source-sink positional arrangements and magnetic force in a discretely heated-cooled annular domain. Single and dual thermal heaters and coolers are placed uniformly or alternatively on the inner and outer cylinders of the annular domain and is applied with a uniform magnetic force in radial or axial directions. This analysis is completely described by the vorticity-stream function-based model equations and are numerically integrated using a stable, implicit Finite Difference Technique (FDM). The positions of thermal heaters and coolers has an important role in controlling the buoyant-induced flow and related thermal characteristics. The flow as well as transport analysis are predicted through contours of stream function and temperature, while thermal transport rates have been estimated from the global Nusselt number. For the positioning of sources and sinks on the same wall, a single-eddy structure exists, while for placement of sources and sinks on opposite walls leads to bi-cellular flow structure. Further, for the case of dual source-sink arrangements, higher thermal transport is predicted from lower source rather than the source place at top location.

Modified hexagonal pin fins for enhanced thermal-hydraulic performance of micro-pin fin heat sinks

PurposeThis numerical study aims to investigate the modification of the hexagonal pin fin geometry to enhance both the thermal and hydraulic performance of the copper micropin fin heat sink with single-phase water coolant in a laminar regime. The heat sink performance evaluation criteria have been investigated for the parametric effects of vertex angle θ (10–120) and relative length (RL) (0.25–9) of hexagonal pin fins.Design/methodology/approachTo carry out research and reduce the computational cost, only one heat sink unit is simulated and analyzed using periodic boundary conditions on the side walls and includes a hexagonal pin fin and half channel on both sides to reflect the structural characteristics completely. The governing equations are also solved using finite volume method.FindingsThe results reveal that θ = 60 and RL = 1 yield the optimum thermal performance and heat sink performance is significantly influenced by the vertex angle and RL. The modified hexagon geometry improves fluid flow behavior by reducing the volume of the recirculation region behind the pin fin, preventing its effects on the downstream pin fins and restricting the thermal boundary layer development on its straight side. At Re = 1,000, the modified geometry enhances the average Nusselt number by 24.46% and the thermal performance factor by 23.89%, demonstrating the potential of modified hexagonal pin fins to enhance micropin fin heat sink performance.Originality/valuePrior studies suggest using the pin fins with a regular hexagonal cross-section to obtain better thermal performance. However, this comes with a higher pressure drop penalty. The modification of the hexagonal pin fin geometry has been investigated in this numerical study to enhance both the thermal and hydraulic performance of the micropin fin heat sink. Because little attention has been paid to the modification of the regular hexagonal pin fins, as a geometry inspired by natural honeycomb structures, its design optimization is relatively scarce, and a gap was felt in this field.

Galerkin scheme on entropy generation in complex fluid involving gyrotactic microorganisms on cylinder/surface via solar thermal radiations

In the current analysis, numerical investigation for double diffusion and gyrotactic microorganisms in complex fluid involving Dufour and Soret influences over stretching cylinder, and stretching surface is investigated new research in recent developments and analysis of such problems are not observed yet in the open literature. Mechanisms of thermal radiation, heat sink, viscous dissipation, chemical reaction and Joule heating are incorporated. Solar water heating, solar cooking, solar power generation and solar desalination are a few examples of practical uses for solar thermal processes. Applications of the current analysis include thermal insulation, biomedical engineering, chemical processing, food preservation, cooling systems and power generation. Moreover, the utilization of a uniform magnetic field is incorporated along the z-direction under consideration of magnetic Reynolds number (low). Such development has been utilized in several industrial and technological applications. This modern physical development is transformed in mathematical modeling regarding highly coupled non-linear PDEs. A set of PDEs (non-linear) is transformed into dimensionless form regarding non-linear ODEs utilizing relevant variables and a numerical solution is achieved using finite element methodology. In this development, essential simulations have been obtained, for example, surface drag force, Nusselt number, mass diffusion rate and microorganism concentration.

The ignition modes transformation and critical parameters for single coal particle under O2/CO2 atmospheres

Oxy-coal combustion with the substitution of CO2 for N2 is a state-of-the-art technology for CO2 capture and storage. Pulverized coal particles show various ignition and combustion characteristics under O2/CO2 atmospheres due to various physicochemical properties between CO2 and N2. A modified transient model with an augmented reduced mechanism (ARM) was developed to predict the ignition delays and ignition modes of the coal particle. Ignition modes transformation and critical parameters for single coal particle under O2/CO2 atmospheres were determined by using the modified transient model and the ignition criteria based on different characteristic ignition time scales. The predicted ignition delays were compared with experimental values and the predicted results obtained from the sophisticated model in literature. The ignition processes of the coal particle under O2/CO2 and O2/N2 atmospheres were analyzed in detail. Then, the contributions of the physical properties of CO2 including thermal conductivity and thermal sink, and the chemical properties of CO2 including gas mixture reactivity and char gasification to the variation of homogeneous and heterogeneous ignition delays and the transformation of ignition modes were separated at 1200–1800 K and 5%–60% O2. Finally, the ignition modes map under O2/CO2 atmospheres was firstly depicted and the critical parameters for ignition mode transformation were compared with O2/N2 atmospheres. The results indicated the larger thermal sink of CO2 and the reduced gas mixture reactivity played the dominant roles of the prolonged homogeneous ignition delays under O2/CO2 atmospheres. The critical gas temperature for the appearance of homogeneous ignition increased by 71 K at 27% O2 whereas the critical O2 concentrations for the ignition mode transformation from HI-GI to HI-coal changed insignificantly with the substitution of CO2 for N2.

Paraffin-Multilayer Graphene Composite for Thermal Management in Electronics

Multilayer graphene-paraffin composites with different contents of graphene (0-10 wt.%) were prepared using an ultra-high shear mixer. The aim is to improve the heat transfer in paraffin wax, which will lead to more-efficient thermal buffering in electronic applications. The multi-layer graphenes obtained by supercritical fluid exfoliation of graphite in alcohol were investigated by Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Interesting morphological features were found to be related to the intercalation of paraffins between the multilayer graphene flakes. Thermal properties were also investigated in terms of phase change transition temperatures, latent heat by differential scanning calorimetry and thermal conductivity. It was found that the addition of graphene resulted in a slight decrease in energy storage capacity but a 150% improvement in thermal conductivity at the highest graphene loading level. This phase-change material is then used as a thermal heat sink for an embedded electronic processor. The temperature of the processor during the execution of a pre-defined programme was used as a performance indicator. The use of materials with multilayer graphene contents of more than 5 wt.% was found to reduce the processor operating temperature by up to 20%. This indicates that the use of such composite materials can significantly improve the performance of processors.

Falkner–Skan slip flow of non-Newtonian fluid over a moving and nonlinearly radiated wedge with variable heat source/sink and viscous dissipation

Analyzed in this paper is an investigation of the impacts of the varying source of heat or thermal sink and viscous dissipation on Casson fluid flow from a moving wedge by considering thermal and momentum slips in a mathematical model. Regarding the regulation of concentration fields, we incorporated the Soret and Dufour phenomena. The outcomes are analyzed numerically by using the shooting technique. The governing parametric effects of the flow characteristics are revealed graphically. We also presented the local Sherwood and Nusselt number values for non-Newtonian fluid (Casson fluid) and Newtonian. It is discovered that the thermal and concentration boundary layer is more extensive in Casson fluid while equated with the Newtonian fluid. The thermal and mass transmission in Newtonian fluid is significantly larger than in non-Newtonian fluid. The heat source/sink, Eckert number and Dufour number boost the rate of thermal transport and depreciate the rate of mass transport for both the Newtonian and non-Newtonian fluid cases.

A design approach for thermal enhancement in heat sinks using different types of fins: A review

This article provides an in-depth overview of thermal heat sink design and optimization. Heat transfer enhancement strategies are discussed in detail, followed by fin design trends and geometries, and a discussion on different fin configurations and their merits is also presented. Important results and findings of experiments concerning the design and optimization of fin geometries have been summarized. For complex heat dissipation applications, researchers have been studying different fin arrangements especially, inclined fins, to maximize the performance of the heat sinks. Along with innovative fin designs, microchannels for heat dissipation are gaining attention due to their. Recent advances in this domain have been discussed. New components are becoming more compact and advanced as a result of technological breakthroughs in electronics and control systems; hence, the use and optimization of heat sinks for modern applications are also discussed in this article.

Combining Finite Element and Machine Learning Methods to Predict Structures of Architectured Interlocking Ceramics

Attaining optimum structural ceramic designs calls for an extensive search in a vast design space. Herein, the thermomechanical properties of interlocked ceramics are evaluated and an approach to assist their design under thermal shock loading is proposed. A combination of finite‐element (FE) and machine learning (ML) methods is used to simulate behaviors of systems and then to sweep the vast domain of input combinations to determine the best‐performing designs, respectively. First, FE modeling is done using a limited number of interlocking architectures with different design parameters via Comsol Multiphysics. The simulation data is used for training ML algorithms. Of the examined ML algorithms, Gaussian process regression (GPR), extreme gradient boosting (XGB), and neural networks (NN) more accurately predict the thermomechanical responses of the interlocking ceramics. After validation, the combination of FE and ML approaches is applied to thermal shielding and heat sink applications to find the optimal interlocked ceramics in terms of minimal out‐of‐plane deformation and maximal heat absorption, respectively. The results show the success of the approach in finding optimum designs in a space of more than 2 million cases. The striking success of the ML approach implies its promising potential for predicting physical properties of ceramics.

Ternary hybrid nanofluid flow caused by thermal radiation and mass transpiration in a porous stretching/shrinking sheet

In the current analysis, ternary hybrid nanofluid flow with heat transfer under the influence of transpiration and radiation is explored. Partial differential equations (PDEs) of the current work are mapped by using a similarity variable to convert into ordinary differential equations (ODEs) form. The volume fractions of the ternary hybrid nanofluid are used in the entire calculation to achieve better results. The exact investigation of the momentum equation produces the domain value. The impact of thermal radiation is considered under energy equation and solved analytically with solution domain to yield the temperature profile. Graphical representations can be used to evaluate the effects of the factors thermal radiation, heat source or sink, and porous media. The present work is taken into consideration for numerous industrial applications.

New thermal packaging with a boiling-driven heat spreader for thermal management of the power electronics

• A boiling-driven heat spreader for the power conversion system. • Thermal management performance was compared among 3 heat spreader designs. • Universal support design is a key design factor for multiple heat source problems. • A numerical methodology was proposed for the boiling-driven heat spreader. A new thermal management device with a two-phase flat heat spreader was designed, fabricated, and characterized. The boiling-driven heat spreader (280 mm × 65 mm × 4 mm) is embedded at the thermal packaging air-cooling heat sink for the power electronics. A sintered microporous structure was coated on the surface in the heat source's direction to promote a boiling heat transfer inside the heat spreader. The thermal management devices are tested with the potential applications consisting of the six heat sources placed vertically. As a result, boiling-driven heat spreaders have proven to be an equivalent thermal management method in applications with multiple heat sources and high heat flux targets. In particular, the heat spreader equipped with a dot-type supporter can make a temperature difference between junctions within 7.6℃ at 1500 W in case of air cooling. Compared to the result (Δ T = 28℃ @ 1500 W) of the solid copper plate of the same size, this thermal packaging demonstrated improved thermal management performance. In addition, we propose a numerical analysis for a boiling-driven heat spreader. The numerical analysis results can predict multiple heat sources' temperature distribution more accurately rather than assume a two-phase heat spreader as a solid with high thermal conductivity. This study provides valuable insight into the thermal management and thermal packaging design of power electronic devices. It represents a breakthrough in resolving the reliability problem of thermal packaging technology and temperature non-uniformity.

Ammonia as an Aircraft Fuel: A Critical Assessment From Airport to Wake

Abstract Zero-emission aviation initiatives have mainly focused on using hydrogen or drop-in biofuels and sustainable aviation fuels (SAF) to replace fossil-based jet fuels to achieve near-term reductions in carbon emissions with minimal impacts on the global aircraft fleet and supporting infrastructure. Despite significant advances in the production of such fuels, scaling up manufacturing capability to be cost-competitive is an ongoing effort. This paper discusses ammonia as a near-zero-emission carrier of green hydrogen for aviation. Ammonia is proposed as a carrier of hydrogen fuel, a thermal sink for compressor intercooling, and cooling of cooling air, for NOx elimination, and for condensation of water vapor to reduce contrail formation. A two-pronged investigation is presented, where first, a holistic discussion on alternative fuels identifies ammonia as a suitable hydrogen carrier for aviation. Second, the implications and potentials of ammonia are discussed and analyzed at the airframe and engine system level. Stemming from the already established fertilizer industry, a robust supply chain for ammonia exists together with experience in handling large quantities of the fluid despite its higher toxicity compared to hydrogen and other alternative aviation fuels of the future. It is found that ammonia requires significantly less water than SAF in production, on par with hydrogen, at comparable life cycle emission levels. The feasibility of heat exchangers for compressor intercooling and turbine-cooled cooling air, enabled by ammonia’s non-coking properties, is demonstrated, and paves the way toward efficient zero-emission engine cores.

Heat Transfer Coefficient Calculation for Developed Ammonia Boiling in the Evaporator Channel of a Thermal Sink

The subject of this article is the heat transfer of ammonia in the channels of thermal sink evaporators. The objective was to determine a sufficiently simple correlation acceptable for engineering practice, which could be used to calculate the heat transfer in cylindrical channels of a thermal sink, designed for two-phase systems of thermal control systems of uncrewed spacecraft. For this purpose, experiments were performed on two thermal sink having an evaporator channel of ~7 mm diameter made of aluminum alloy and stainless steel, with channel surface roughness Ra 3.33 µm and 0.12 µm. The experiments were carried out with a subcooled liquid or two-phase flow at the channel inlet. The results of the experiments were compared with Kupriyanova's formula obtained under markedly different conditions: with ammonia boiling in a large volume on the external surface of 5...6 mm diameter tubes at –40 °C...+20 °C. It is shown that Kupriyanova's formula can be used on the ground and in microgravity conditions to calculate heat transfer coefficients during the developed boiling of ammonia in the range of flow parameters: saturation temperature +35 °C...+75 °C; mass velocity 27...200 kg/(sec-m²); liquid subcooling to saturation temperature at thermal sink inlet 0 °C...30 °С; mass vapor quality at the inlet 0...0.7. Difference of calculated and experimental values of heat transfer coefficients did not exceed 30 %.

The effect of different carrier fluids on heat transfer performance in a microfluidic serpentine device

In this work, the efficiency of heat transfer and the related fluid-mechanic performance inside a microfluidic device are investigated by varying the type of carrier fluid at different flow rates. The experimental analysis has been conducted on a serpentine channel configuration by considering five different fluid mixtures. The results displayed and emphasized the relevant role of viscosity on thermal performance in the laminar regime. The corresponding Nusselt number values have been identified in terms of Reynolds and Prandtl numbers. Specifically, high-viscosity mixtures exhibited Nusselt number values strongly correlated with Prandtl number. So far, heat transfer for these mixtures is improved as a result of the greater extent of the thermal entrance region and of the higher thermal gradient. Nusselt-Reynolds trends for such mixtures also presented a consistent rate of increase, this increment being however severely limited by the action of viscous dissipation as Reynolds number increases. On the other hand, mixtures with low viscosity showed high correlation between Nusselt and Reynolds numbers. The importance of local turbulence phenomena for such low-viscosity fluids becomes one of the main factors in heat transfer enhancement, also for small-scale thermal sinks in laminar regime. In fact, for such mixtures, thermal performances are incremented by the combining effects of local mixing phenomena at each bend of the serpentine and by the increasing extension of the thermo-hydraulic development region.

Comprehensive examination of radiative electromagnetic flowing of nanofluids with viscous dissipation effect over a vertical accelerated plate

This research aims to establish the MHD radiating convective nanofluid flow properties with the viscous dissipation across an exponentially accelerating vertical plate. As the plate accelerates, its temperature progressively increases. There are two separate types of water-based nanofluids that include copper (Cu) and titanium dioxide (Ti{O}_{2}) nanoparticles, respectively. The most crucial aspect of this investigation is finding a closed-form solution to a nonlinear coupled partial differential equations scheme. Galerkin finite element method (G-FEM) is used to figure out the initial managing equations. Utilizing graphs, the effect of the flow phenomenon's contributing variables as well as the influence of other factors is determined and depicted. In the part dedicated to the findings and discussion, the properties of these emergent parameters are described in more depth. Nonetheless, the thermal radiation and heat sink factors increase the thermal profile. In addition, the greater density of the copper nanoparticles cause the nanoparticle volume fraction to lessen the velocity delineation.

Electrocaloric heat pumps using two independently-controlled layers to achieve high cooling power

The development of electrocaloric materials (ECMs) with strong electrocaloric effect (ECE) in recent years offers a great opportunity for the development of solid-state heat pumps without using environmentally unfriendly vapor-based technologies. Currently existing ECE-based heat pumps (CEHPs) use one ECM layer that has to be moved back and forth between the thermal source (SO) and sink (SI), which raises reliability and safety concerns. Here, a design, which uses two layers of an ECM and the electric field on each layer is independently controlled with a special pattern, is introduced to develop ECE-based heat pumps with a high cooling power. In the design, the two ECM layers are permanently bound together and used as a single ECM module. The performance of the heat pumps is calculated using the newly introduced analytical solutions. First of all, it is found that the cooling power of CEHPs is strongly dependent on, while the cooling power of heat pumps using the two-ECM-layers module (TELM) is insensitive to, the materials used as the SO/SI. This would significantly expand the application of ECE-based heat pumps since in many applications there is no freedom to choose the materials to be used as the SO/SI. Secondly, the heat pumps using the TELM exhibit a high cooling power. For example, when different materials are used as the SO/SI, the cooling power of CEHPs would be changed over more than 100 times, while it is only changed less than 2 times when the TELM is used to replace the ECM layer used in CEHPs. And the cooling power of heat pumps using the TELM can be more than 7 times higher than the highest cooling power obtained in CEHPs. More importantly, the TELM can be permanently bound to the SO (or the SI) (i.e., the ECM is not moved at all during the operation), which would result in a high reliability. In this case, the cooling power of the heat pumps using the TELM can only be changed less than 25 % when different materials are used as the SO/SI and this cooling power is close to the highest cooling power obtained in the CEHPs.

Fabrication and thermal tests of SS/Cu bimetal plate for the use in the concept of flowing liquid lithium layer in tokamak limiters and divertors

A prospective technology for manufacture of the tokamak divertor target based on the concept of flowing liquid lithium layer is described. A small-size bimetal plate was produced by the hot isostatic pressing diffusion bonding of a thick solid copper base, which serves as a thermal sink, and a thin (0.2 mm) stainless-steel foil, which serves as a corrosion-resistance coating. The mock-up with cooling channels in the copper sink was tested by loading the stainless-steel surface by a high heat flux in two loading modes. First, the absorbed heat flux density was increased step-by step from 0.5 MW/m2 to 11.9 MW/m2. Second, thermocycling (1000 cycles) at an absorbed heat-flux density of about 8 MW/m2 was performed. The mock-up demonstrated acceptable uniformity of the temperature on the surface without spot overheating and good stability in thermal cycling in the range of RT-500 °C. No defects were observed after the tests performed.

Spectral relaxation computation of Maxwell fluid flow from a stretching surface with quadratic convection and non-Fourier heat flux using Lie symmetry transformations

A mathematical model for nonlinear quadratic convection with non-Fourier heat flux in coating boundary layer flow of a Maxwell viscoelastic fluid is presented. Nonlinear quadratic thermal radiation and heat source/ sink effects are also considered. The transformations of Lie symmetry are employed. The resultant nonlinear differential equations with defined boundary conditions are numerically solved using the spectral relaxation technique (SRM), a robust computational methodology. Graphical visualization of the velocity and temperature profiles is included for a range of different emerging parameters. For skin friction and the Nusselt number, numerical data are also provided. There is a very strong correlation between the outcomes of this study and those published in the literature. Higher values of the nonlinear thermal radiation, mixed convection, thermal conductivity, nonlinear convection and heat source/ generation parameters increase temperature as well as the thickness of the thermal boundary layer. However, a higher Prandtl number, thermal relaxation parameter and heat sink/ absorption parameter all reduce temperature. Deborah number causes velocity to be raised (and momentum boundary layer thickness to be lowered), whereas raising nonlinear mixed convection parameter causes velocity to be decreased (and momentum boundary layer thickness to be increased), and a velocity overshoot is calculated. The models are applicable to simulations of high-temperature polymeric coatings in material processing.

The influence of seasonal land-use-land-cover transformation on thermal characteristics within the city of Pietermaritzburg

Urbanisation has been identified as a major threat to the environment as it increases demand for urban spaces and transforms natural landscapes to impervious surfaces, leading to the Urban Heat Island (UHI) phenomenon. Natural landscapes such as vegetation and water bodies act as thermal sinks that absorb heat while impervious surfaces such as buildings and concrete pavements act as thermal sources that retain and emit heat. The thermal emission results in several negative effects such as temperature inversion, compromised human health, pollution, species loss, high energy consumption and climate change at a local, regional and global scales. Whereas studies on UHI are abound, there is paucity in literature on the influence of seasonal urban Land Use Land Cover (LULC) transformation on urban thermal characteristics. Specifically, the proportional seasonal variability and contribution of individual LULCs to urban heat is often poorly understood. Using the freely available Landsat 8 optical and thermal bands, this study examined the seasonal characteristics of the UHI phenomenon in relation to LULCs in the Pietermaritzburg city, South Africa. Results in this study revealed that UHIs exist in both winter and summer, but with more intensity in summer. The study also established that LULCs varied with seasons. Bare surfaces and dense vegetation had the most thermal influence during winter while dense vegetation and low density buildings had the most thermal influence during summer. These findings provide a better understanding of thermal distribution based on LULC seasonality changes, valuable for sustainable urban planning and climate change mitigation.

The potential of natural shade provided by Brazilian savanna trees for thermal comfort and carbon sink

This study looked at the potential of thermal comfort provided to animals by four different Brazilian savanna (Cerrado) native trees, as well as their potential for carbon sink. The evaluations were carried out during the summer of 2020, which consisted of the collection of microclimate variables. The Mean Radiant Temperature (TMR, °C) was derived from the shaded and unshaded areas under the trees, and from that, the Radiant Heat Load (RHL, W m−2) was calculated as an index of thermal comfort. Solar radiation was estimated considering the sum of the direct, diffuse, and reflected components (W m−2), and carbon stock from trees biomass for CO2 sequestration was estimated from an allometric model applied to the native Cerrado tree species. The shade of the native trees reduced the meteorological variables such as dry bulb and black globe temperatures, to values considered adequate for the thermal comfort of animals, with an average reduction respectively equal to 1.3 °C and 6.4 °C. This represents a significant difference compared to the unshaded area as well as among tree species (P < 0.05), reflecting in lower values of TMR and RHL in the shaded area provided by each species. Carbon sequestration individually estimated by each native tree species was on average 8.85 Mg per tree. These results demonstrate the great potential for native tree species in the Cerrado biome to be used in agroforestry systems to provide higher levels of thermal comfort to animals and to combat climate change through their aptitude of CO2 sink.

FRIDGE – The next generation freezer/refrigerator/incubator for food and experiment conditioning onboard the ISS

The Freezer / Refrigerator / Incubator Device for Galley and Experimentation (FRIDGE) is a middeck locker-sized unit developed by BioServe Space Technologies for use within the Galley rack of the International Space Station (ISS) for food storage as well as in the EXPRESS rack for science experiment support. FRIDGE was optimized to provide a large Temperature Controlled Compartment (TCC) volume with the interior dimensions of 43.8 × 28.2 × 19.7 cm (17.25 × 11.10 × 7.75 in, DxWxH), which can be temperature-controlled from -20 to +48 °C. Temperature control of the TCC is accomplished using a total of four thermoelectric coolers (TECs) mounted to the top and bottom surfaces of the TCC. FRIDGE utilizes the ISS-provided Moderate Temperature Loop (MTL) as a thermal sink for the TECs and avionics. FRIDGE is based and improved on the Space Automated Bioproduct Lab (SABL) that has been in continuous operation onboard the ISS for over 5 years. Thermal improvements include the addition of vacuum panels into the insulation, optimized heat exchanger heat distribution and removal, improved door design, as well as the use of novel multistage bidirectional heat pumps (TECs). FRIDGE was designed without a single rotating part to minimize any maintenance work. This paper focuses on the thermal, mechanical, electrical, and software design of the payload compared to the initial test results from the verification testing. Thermal feedback control and safety monitoring is implemented using a suite of sensors that interface to an NI sbRIO-9636 data acquisition and control computer. Performance of the engineering unit was characterized to verify thermal models of operation, cooling/heating times, and robustness against uneven internal heat loads and off-nominal operation. After starting development at the end of 2018, the first two out of eight FRIDGE units were launched onboard NG-14 and commissioned onboard the ISS in the fall of 2020.This work was made possible by the National Aeronautics and Space Administration under grant REMIS-C2A-TO-003-GRF.