Unidirectional Heat Transfer Research Articles

Design and experimental analysis of a novel thermal diode with asymmetric heat transfer inspired by feather

To overcome the limitation of isotropic heat transfer of traditional heat pipes, a novel thermal diode with asymmetric flow resistance vapor channel inspired by the goose feather fibers is proposed in this study. The thermal performance of novel thermal diode is experimentally investigated. Results show that under the wide range of operating conditions, the thermal resistance of one end surpasses the thermal resistance of the other end, indicating its excellent thermal rectification capability. Under the filling ratio of 10 % and heating power of 7.5 W, the maximum thermal resistance of the thermal diode is 5.23 times the minimum thermal resistance, demonstrating excellent asymmetric heat transfer performance. Experimental results demonstrate that the novel thermal diode proposed in this study can easily change its unidirectional heat transfer direction by simply adjusting the internal filling ratio, showing significant application potential in the fields of thermal control system.

Study on freezing separation process through observing microstructure of NaCl solution ice

Freezing desalination is a method to purify saline water. Researchers believe that the salt inclusions distributed inside ice affect the sea ice salinity, but there is not sufficient visualized proof that has been obtained via direct and non-destructive experiments to support this view. Even less study has been carried out on the salt inclusion distribution inside ice below the eutectic temperature. In this paper, a NaCl solution ice sample was prepared with the original mass concentration of 3 wt% using unidirectional heat transfer method. The freezing temperature was −24 ℃, which is lower than −21.2 ℃, the eutectic temperature of NaCl solution. Micro-CT device was used to scan the upper, middle and lower parts of a 3 wt% NaCl solution ice sample and the 5-layer U-Net architecture in DL (deep learning) module of the Dragonfly program was used to segment images to extract the information of interest. The image characteristics of salt inclusions and air bubbles inside the ice were obtained. Very high salt inclusion area proportion was found in the surface layer images of the sample with the maximum area proportion of about 43%. Experiments were also carried out to measure the salinity distribution inside the same solution ice samples. It was found that in the surface and bottom ice layers, the salinity is higher than that of the original solution. In the experiments, for the layers cut from the top and bottom of the 3 wt% NaCl solution ice sample, each of them possesses 10% of the solution ice sample mass, their salinities were 4.28 wt% and 5.41 wt%, respectively. Comparing the measurement results with the micro-CT image processing results, it was found that the variation tendency of the area proportion of salt inclusions is consistent with that of the ice layer salinity. The combination of micro-CT technology with DL image processing method has been proved an effective way to visualize and analyze quantitatively the internal structure of salt solution ice. Then, three NaCl solution samples that have the original mass concentrations of 3 wt%, 6 wt% and 9 wt%, and a pure water sample were frozen under the same conditions. The middle parts of the four ice samples were scanned and the obtained micro-CT images were processed. It can be found that in the middle parts of the three NaCl solution ice samples, the area proportions of salt inclusions increase from top to bottom and are positively correlated with the original salinities of the solution ice. The factors affecting air bubble distribution are more complex than that affecting salt inclusion distribution.

Development of novel thermal diode inspired by the structure of venous valve

To increase the unidirectional heat transfer capability of a thermal diode, a novel thermal diode with unidirectional movable valves as vapor channel is proposed based on the structure of venous valves. The thermal performance of this bionic thermal diode was experimentally investigated under different working conditions. The results demonstrate that the bionic thermal diode exhibits a high thermal rectification ratio and strong stability. The best thermal rectification ratio is 10.79, with a forward thermal resistance of 0.26 °C/W and a reverse thermal resistance of 2.86 °C/W, at a heating power of 15 W and a filling ratio of 15 %. The temperature distribution indicated that, under the reverse heat transfer mode, the vapor was obstructed at the first valve, leading to the high thermal resistance of thermal diode. Additionally, the effect of inclined angle on the thermal performance of thermal diode was also investigated. This study provides a novel approach for the design of thermal diodes.

Numerical study of the particle-scale heat transfer in the HTR-PM pebble bed based on GPU-DEM

An essential aspect of the design of a pebble bed high-temperature gas-cooled reactor (HTGR) is the consideration of heat transfer. A particle-scale heat transfer model was developed based on the previous GPU-DEM numerical model. This model includes the heat conduction of the particles in contact, the radiative heat transfer among particles, and unidirectional convection heat transfer in the flow field. The comparison of the predicted results with the results of the TF-PBEC experiment demonstrates the accuracy of the conduction and radiation modules within the current model. Based on the current model and the porous media model, a numerical study of the natural convection heat transfer in the High-Temperature gas-cooled Reactor-Pebble-bed Module (HTR-PM) after reactor shutdown is performed. This paper systematically introduces the model design, pebble bed generation, flow field calculation, and heat transfer simulation. The results indicate that natural convection contributes to removing residual heat in the reactor core, and a higher pressure leads to better convection heat transfer. At extremely low Reynolds numbers (Re < 10), convection heat transfer is comparable to conduction and radiation, while for pressurized pebble beds (Re = 50–500), convection heat transfer dominates. Furthermore, the influence of different models used to calculate the Nusselt number of the results is compared and analyzed. For most cases, the differences in the temperature distribution of the pebble bed obtained from the different correlations are minor. However, the impact of porosity on the local Nusselt number cannot be ignored in the extremely low Reynolds numbers flows. Overall, the particle-scale heat transfer model can provide more effective reference information for the design and construction of an HTGR.

Ultrafast Unidirectional On-Chip Heat Transfer.

Effective and rapid heat transfer is critical to improving electronic components' performance and operational stability, particularly for highly integrated and miniaturized devices in complex scenarios. However, current thermal manipulation approaches, including the recent advancement in thermal metamaterials, cannot realize fast and unidirectional heat flow control. In addition, any defects in thermal conductive materials cause a significant decrease in thermal conductivity, severely degrading heat transfer performance. Here, the utilization of silicon-based valley photonic crystals (VPCs) is proposed and numerically demonstrated to facilitate ultrafast, unidirectional heat transfer through thermal radiation on a microscale. Utilizing the infrared wavelength region, the approach achieves a significant thermal rectification effect, ensuring continuous heat flow along designed paths with high transmission efficiency. Remarkably, the process is unaffected by temperature gradients due to the unidirectional property, maintaining transmission directionality. Furthermore, the VPCs' inherent robustness affords defect-immune heat transfer, overcoming the limitations of traditional conduction methods that inevitably cause device heating, performance degradation, and energy waste. The design is fully CMOS compatible, thus will find broad applications, particularly for integrated optoelectronic devices.

Ultrahigh freshwater production achieved by unidirectional heat transfer interfacial evaporation solar still integrated with waste heat recovery

Solar-driven interfacial evaporation technology exhibits notable performance in evaporation, with evaporation efficiency typically maintained at over 80 %. However, utilizing interfacial evaporation for efficient seawater desalination remains a challenge due to low production of freshwater. Therefore, we propose a desalination system based on unidirectional heat transfer solar still, which is capable of combining efficient evaporation with waste heat recovery to achieve high energy utilization. The design of the solar still decomposes the light transmission and condensation functions of the glass cover plate in traditional solar still for independent optimization and reserves space for integrating high-performance interfacial evaporation materials, while minimizing heat loss by ensuring unidirectional heat transfer inside the still. In particular, the proposed unidirectional heat transfer solar still provides a free interface to condense the vapor, where a multi-stage condensation is integrated to recycle latent heat. When using a self-made hydrogel sponge as the interfacial evaporation material, the solar still achieve efficient and stable freshwater production. Outdoor experiments showcase a evaporation rate of 6.0 kg·m−2·h−1, coupled with an freshwater production rate of 4.5 kg·m−2·h−1 under an average sunlight intensity of 1.07 kW·m−2. Our results demonstrate that the freshwater production of the solar still can be further improved. This work is beneficial for further enhancing freshwater collection of solar desalination.

Bio‐inspired Thermal Diode with Anti‐Gravity Unidirectional Heat Transfer and Switchable Functionality for Intelligent Thermal Management

AbstractPhase‐change thermal diodes with asymmetric and adjustable heat transfer capacity exhibit great application prospects in spacecraft heat management and solar energy storage. Current heat modulation strategies mainly depend on the anisotropic assistance from gravity and the rectification ratio can hardly be adjusted due to the immobilized inner structures. Here, a novel bioinspired thermal diode vapor chamber has been carried out with magnetic microgroove cones array sealed between two copper plates, where the evaporating plate with porous copper foam can reserve water and the condensing plate with patterned wettability can coagulate vapor into droplets at designated spot. With microgroove cones rooting from the evaporating plate and their tips contacting the condensing plate, these cones can directionally and rapidly transport condensed liquid from the condensing plate to evaporating plate under the unbalanced strong capillarity while prohibiting water flowing backward. This eventually leads to unidirectional liquid‐vapor circulation and anti‐gravitational directional heat transferring with a rectification ratio as high as 7.4. Such flowing of liquid can also be regulated by magnetically controlling the bending of cones to realize switched ON–OFF of thermal diode and achieve further modulation of heat management. This bioinspired thermal diode vapor chamber provides new ideas for intelligent thermal management systems.

Unidirectional heat and fluid transfer performances of a thermal diode with fishbone-microstructure wicks

A thermal diode is fabricated with remarkable unidirectional heat transfer performance. It shows long-distance heat transmission and working adaptiveness, providing a valuable insight for designing thermal management devices to meet extreme demands.

CFD analysis and optimization of thermal stratification in a Thermal Diode Tank (TDT)

Thermal stratification is a common and natural phenomenon in energy storage tanks. This paper presents a Computational Fluid Dynamics (CFD) analysis of thermal stratification within a novel cold energy storage, termed a Thermal Diode Tank (TDT). The TDT is a well-insulated water tank equipped with heat pipes for unidirectional heat transfer from water to the ambient air. When integrated into a Refrigeration and Air-conditioning (RAC) system, it provides cooling water to reduce the condensing temperature. The research problem revolves around the impact of thermal stratification on TDT performance and the identification of the optimal TDT structure when thermal stratification is present. Therefore, this study aims to employ CFD to simulate temperature profiles within a TDT, both with and without an obstacle. With validated models, parametric analysis has been conducted to determine the optimal TDT structure. Several design parameters have been investigated, including tank orientation, heat transfer capacity, the ratio of obstacle axial height to TDT height (ho/H), and the ratio of obstacle hole diameter to TDT diameter (do/D). Key findings reveal that a vertical tank orientation is more conducive to improving the TDT assisted RAC system performance than a horizontal one. Increasing the TDT's heat transfer capacity also positively contributes to the system performance. Parameters of an optimal TDT structure include a ho/H ratio of approximately 0.43 and a do/D ratio of 0.4. It is found that the do/D ratio should be at least 0.15 to obtain positive stratification. Furthermore, the presence of thermal stratification can increase the system's Coefficient of Performance (COP) by up to 10 %.

The energy saving performance of the thermal diode composite wall in different climate regions

The effective management of energy consumption during building operations continues to be of utmost importance. The role of a building's envelope in regulating energy consumption is critical. However, traditional building insulation systems often struggle to maintain optimal indoor temperatures in the face of fluctuating external temperatures. Solar energy, for instance, can easily penetrate a room through windows during the cooling season, leading to increased energy consumption. Similarly, heat dissipates easily during the heating season. To address these challenges, thermal diode composite walls with unidirectional heat transfer offer a groundbreaking approach to simplifying the design of thermal management systems. The thermal diode composite wall effectively controls heat conduction, convection, and radiation through the implementation of different functional layers. By regulating the heat flux through the building envelope, this technology significantly reduces energy consumption during building operations while maintaining a stable indoor temperature. To evaluate the performance of an adaptable thermal diode composite wall, we designed, implemented, and conducted tests on a thermal diode composite wall building. The results of the study demonstrate substantial energy savings, ranging from 3.5% to 69.3% for annual operation in various regions, with better performance observed in colder regions. In the forward heat conduction mode, the temperature difference between the inside and outside wall surfaces reached a maximum of 20.99 K, while in the reverse mode, it reached −35.67 K. These findings highlight the remarkable potential of thermal diode composite walls in significantly improving the energy efficiency and comfort of buildings. Consequently, the adoption of thermal diode composite walls presents numerous opportunities for the development of low-carbon buildings.

Design and thermal performance of thermal diode based on the asymmetric flow resistance in vapor channel

To reduce the cost of the thermal diodes and increase its unidirectional heat transfer reliability, a thermal diode with tesla valve structure is proposed and its thermal performance is experimentally investigated. The relation between the structure parameters (including branch angleα, channel depth d, number of unit n and number of channel N) and the fluid flow performance of tesla vapor channel is studied by numerical simulation. According to the simulation results, the parameters of α = 30°, d = 1.5 mm, n = 16 and N = 4 were chosen for the vapor channel in thermal diode. Experimental results show that the reverse thermal resistance is larger than the forward thermal resistance under the wide range of working conditions, indicating the good unidirectional heat transport capacity of the proposed thermal diode. The maximum ratio of reverse thermal resistance to forward thermal resistance K reaches around 3.02 under the filling ratio of 24% and the heating power of 7 W.

Thermal assessment of a new planar thermal diode integrated collector storage solar water heater in different partial vacuums: An experimental study

Thermal diodes are novel mechanisms with high thermal resistance in one direction and low thermal resistance in the other. The current study introduces a new planar thermal diode integrated collector storage (ICSs) system and analyzes its transient dynamics and performance under field conditions in several scenarios, including operating at atmospheric pressure and partial vacuums: Ptotal = 0.7 atm and 0.5 atm. The acquired data illustrate that the collector has approximately the same transient dynamics during the collection period, while differences pronounce during the retention period. Utilizing partial vacuums is tricky and may cause to decrease in performance; however, the best retention and collection efficiencies were obtained at 16.97% and 29.33% when Ptotal = 0.7 atm was utilized. Increasing the partial vacuums to Ptotal = 0.5 atm decreases the retention efficiency significantly to nearly 3.26%. The heat gain (forward mode) coefficient was not affected significantly by partial vacuums. However, the heat loss (reverse mode) coefficient was reduced by nearly 17.63% at Ptotal = 0.7 atm compared to atmospheric pressure. The calculated heat gain and heat loss coefficients are 9.28 W/k and 19.65 W/k at Ptotal = 0.7 atm; hence, the constructed thermal diode successfully serves as a unidirectional heat transfer mechanism.

Thermal Diffusivity of Concrete Samples Assessment Using a Solar Simulator.

The thermal properties of pavement layers made of concrete with varying bulk densities are a particularly interesting topic in the context of development road technologies. If a hybrid layer system is used as a starting point, with thin asphalt layers (from 1 cm to 4 cm) laid on top of a foam concrete layer, thermal properties begin to play a crucial role. The main research problem was to create a test method enabling the assessment of the influence of solar heating on the thermal parameters of the building material, especially cement concrete. For this reason, this paper is concerned specifically with the assessment of a new methodology for testing and calculating the value of the thermal diffusivity coefficient of samples made of concrete varying bulk densities. In this case, using the proprietary concept the authors built a solar simulator using a multi-source lighting system. The analysis of the results of laboratory tests and numerical analyses allowed the authors to observe that there is a strong correlation between the bulk density of samples heated and the thermal diffusivity parameter, which appears in the unidirectional heat transfer equation. The strength of this relationship has been expressed with the coefficient of determination and amounts to 99%. The calculated values of the coefficient of thermal diffusivity for samples made of foam concrete range from 0.16×10-6m2s to 0.52×10-6m2s and are lower (from 2.5 to 8 times) than the value determined for samples made of typical cement concrete.

Radiation-enhanced thermal diode tank (RTDT) for refrigeration and air-conditioning (RAC) systems

A Thermal Diode Tank (TDT) is invented for energy conserving purposes that can passively produce cooling water at a minimum night ambient temperature. The TDT is an insulated water tank equipped with heat pipes, which provides unidirectional heat transfer from the TDT water to its surroundings. The conventional heat pipes dissipate heat mainly by convection heat transfer, which are termed Convective Heat Pipes (CHPs), and a TDT equipped with CHPs is a Convection TDT (CTDT). To promote the TDT performance in generating cooling water at a lower temperature, a Radiation-enhanced Heat Pipe (RHP) is proposed with a flattened hollow cuboid as its condenser section to radiate heat to the night sky, while maintaining the convection heat transfer with air. Such a Radiation-enhanced TDT (RTDT) is expected to have a better water-cooling performance than CTDT currently obtains, and could potentially cool the water below the minimum ambient temperature. In this paper, performance simulation models for both RTDT and CTDT have been developed and validated by the experiment. The results reveal that the RTDT generates colder water than CTDT does, and the heat transfer capacity of the RTDT is approximately twice as high as that of the CTDT if they are made from the same quantity of materials. It is found not advisable to promote the TDT performance by increasing the air circulation at the heat pipe condenser. However, analysis shows that increasing the heat pipe condenser area dominantly contributes to the enhancement of TDT performance, especially for RTDT.

Analytical and Numerical Studies of Transient Heat Transfer in Soil for Geothermal Systems

The study of geothermal systems requires a good knowledge of heat transfers in the depth of the soil. The aim of this work is to study the distribution of temperature in the ground under the climatic conditions of Togo. The analytical and numerical solutions of unidirectional heat transfer equation assuming the soil as a semi-infinite medium are found. The analytical solution is validated by comparing the results of the present work to those found in literature. A good qualitative agreement between these results was noted. The results show that the attenuation depth decreases when the attenuation accuracy of the thermal wave increases. The analysis of the effect of moisture content indicates that the increasing in soil conductivity with moisture result in the decreasing of the attenuation depth. Soil temperature increases when increasing soil thermal diffusivity. It is found also that, soil temperatures decrease with depth and stabilize around an average value of 30°C for depths greater than about 5.8 m for all type of soil studied in the month of March which is the hottest month of the year in Togo. A gradual decrease in temperature can be seen from March to August (hot period) followed by stabilization at around 28°C with a depth of 5.8 m. The phenomenon is reversed for the months of September to February (cold period). The soil warms up slowly during the day and cools down slowly at night because of the thermal inertia of the soil. A decrease in amplitude of the thermal wave near ground surface, is observed when the Leaf Area Index (LAI) increases. However, ils influence on the stabilization depth is not very significant. Stabilization of soil temperatures in March month is observed at a depth of about 40 cm for all LAI with a value of 37°C.

Thermal rectification in polytelescopic Ge nanowires

Herein we served non-equilibrium molecular dynamics (NEMD) approach to simulate thermal rectification in the mono- and polytelescopic Ge nanowires (GeNWs). We considered mono-telescopic structures with different Fat-Thin configurations (15-10 nm-nm or Type (I); 15-5 nm-nm or Type (II); and 10–5 or Type (III) nm-nm) as generic models. We simulated the variation of thermal conductivity against interfacial cross-sectional temperature as well as the direction of heat transfer, where a higher thermal conductivity correlating to thicker nanowires, and a more significant drop (or discontinuity) in the average interface temperature in the positive (or negative) direction were detected. Noticeably, interfacial thermal resistance followed the order of Type (II) (48 K/μW, maximal) ˃ Type (III) ˃ Type (I) (5 K/μW, minimal). In the second stage, a series of polytelescopic nanostructures of GeNWs were born with consecutive cross-sectional interfaces. Surprisingly, larger interfacial cross-sectional areas equivalent to smaller diameter changes along the GeNWs were responsible for higher temperature rectification. This led to a very limited thermal conductivity loss or a very high unidirectional heat transfer along the polytelescopic structures - the key for manufacturing next generation high-performance thermal diodes.

Preparation and characterization of magnetized GO nanoparticle enhanced microencapsulated phase change material for thermal energy storage application

ABSTRACT Novel magnetized nanoparticle nickel-graphene oxide / n-octadecane/ melamine-formaldehyde (MF) composite phase change material (MnCPCM) for enhanced solar thermal energy storage(STES) is prepared via in situ polymerization. The magnetized nanoparticles in CPCM promoted the thermal energy storage capacity as well as photothermal conversion efficiency of the composite by the unidirectional heat transfer flow. For these composite PCM, the thermal conductivity is found as excellent and more than that of pure n-octadecane (0.153 W/mK) because of the presence of highly conductive magnetized GO. The role of magnetized Ni-GO nanoparticles in the structure and properties of the microencapsulated PCM is characterized by the SEM, optical microscopy, FTIR, XRD, DSC, thermogravimetric analysis and differential thermal analysis. SEM and optical microscopy reveal that the microencapsulated PCM has uniform spherical morphology. TGA and DTA results show the CPCM is stable up to a temperature of 350 °C. XRD analysis indicates highly ferromagnetic material is well composed with GO to enhance the directional heat flow. DSC analysis shows that the composite is stable up to 100 thermal cycling processes. The enhanced heat transfer flow and better leakage-preventing performance might be highly chosen for STES storage applications of the CPCM as well as heat sink integrated passive cooling.

A Numerical Study on Heat Transfer Enhancement and Fluid Flow of Enhanced Tube With Ellipsoidal Dimples and Protrusions

Abstract Heat transfer enhancement is an important thermal–hydraulic phenomenon in heat exchangers. Previous investigations mostly focused on unidirectional heat transfer enhancement inside the tube. In order to realize the bidirectional heat transfer enhancement inside and outside the tube, an enhanced tube with ellipsoidal dimples and protrusions is proposed. Through comparison among three computational conditions, the non-conjugate and periodic condition is adopted in this paper. Flow characteristics and heat transfer performance of the enhanced tube are investigated by numerical method. The distributions of temperature and flow fields are carried out to illustrate the heat transfer enhancement mechanisms. The Nusselt number, friction coefficient, and performance evaluation criteria (PEC) are presented to reveal thermal–hydraulic performance. Moreover, the effects of the geometric parameters such as dimple depth, dimple pitch, dimples/protrusions numbers in the circumference, and arrangement mode on thermal–hydraulic characteristics are investigated. The results show that the structure of dimples and protrusions induces intensive impingement and interrupts the boundary layers, improving the heat transfer for the internal and external flow, respectively. Besides, the Nu increases with depth and dimples/protrusions numbers in the circumference and decreases with the pitch in most cases. The overall heat transfer performance of staggered arrangement is better than that of aligned arrangement. For the present parameter conditions, when D = 2 mm, P = 25 mm, n = 6, and Re = 5000, the largest PEC of 1.40 and 1.42 occurs for the internal and external flow, respectively.

Unidirectional wicking-driven flow boiling on tilted pillar structures for high-power applications

Energy management issues of data center cooling systems have been aggravated because of the miniaturization of electronic components. The cooling systems consume considerable energy, requiring more electric power supplied by power plants to prevent system failure from overheating. Among cooling methods applied in industrial fields, two-phase immersion cooling is the most potential cooling method for resolving energy consumption issues with extraordinary heat transfer capacity. To further augment the overall heat transfer performance, we propose polymerized surfaces with anisotropic pillar structures, generating a unidirectional wicking behavior to augment capillary-driven force when liquid propagation corresponds with the pillar tilted direction.Further, we first experimentally determined the effect of the anisotropic pillar structures concerning wicking direction on heat transfer in subcooled flow boiling (40 K). When micropillars were tilted toward the convective flow direction (compared to against the flow direction), the unidirectional wicking enhanced the critical heat flux (CHF) by 31%, showing a directional dependence on tilted pillars. The anisotropic wicking surfaces can apply to high-power applications with their unique unidirectional wicking-driven heat transfer and high substrate selectivity.

Experimental investigation on nanoalloy enhanced layered perovskite PCM tamped in a tapered triangular heat sink for satellite avionics thermal management

Miniaturization of circuitry has inherently led to higher heat dissipation which has to be controlled to avoid temperature fluctuation ensuring smooth functioning of the system where developments in the field of PCM provides flexible solutions for avionic Thermal Management (TM). This article focuses to analyse thermal performance of novel tapered triangular finned heat sink along with Vacuum Insulation Panels (VIPs) tamped with nanoalloy (n-LMA) enhanced organo-metallic Mn based layered perovskite Solid-Solid PCM (SS-PCM) to its compatibility for passive TM satellite auxiliary system. An inclusion of 5 wt% nanoalloy (Nano-encapsulated liquid Ga:In eutectic alloy) in SS-PCM increased the thermal conductivity by 21.05% (0.374 W/m-K) and charging and discharging enthalpy by 16.84% (74.56 J/g) and 17.61% (76.32 J/g) respectively. Thermo-physical property values were obtained through Field Emission Scanning Electron Microscope, Scanning Electron Microscope, Differential Scanning Calorimetry and Laser Flash Apparatus. Transient thermal performance analysis was carried out in tapered triangular finned heat sink with specific duty cycles (600s/5400s, 1200s/4800s and 1800s/4200s) for heat fluxes (2 W, 4 W, 6 W, 8 W and 10 W) and with/without VIP for different aspects of SS-PCM and SS-PCM/n-LMA. The effect of n-LMA influences the enhancement in thermal storage and heat transfer performance attributes with a maximum temperature drop of 6.98% over pure SS-PCM. Experimental study reveals better temperature reduction with a maximum of 53.81% decrement in overall heat sink temperature and VIP manifests unidirectional heat transfer through the heat sink reducing overall spatial temperature variation. Further, numerical validation was performed for obtained results with COMSOL application, demonstrating the suitability for real-time passive TM in satellite avionics space applications.