Performance Of Minichannel Heat Sink Research Articles

Experimental and numerical investigation on turbulent convection enhancement in minichannel heat sink with staggered V-shaped pin fins

With the continuous advancements in new energy vehicle technology, the insulated gate bipolar transistor (IGBT) thermal properties have a direct impact on power system reliability. In this article, a minichannel heat sink with staggered V-shaped pin fins (SVPF) is investigated through both experimental and numerical approaches. Initially, the heat transfer performance of SVPF and conventional minichannel heat sink was analyzed using the CFD numerical simulation method. Subsequently, numerical and experimental validation was carried out by assessing the Nusselt number and turbulence characteristics of SVPF. Finally, an in-depth analysis was conducted to investigate the effects of SVPF geometric parameters on the turbulent characteristics and heat transfer performance of the minichannel heat sink. The results demonstrate that SVPF exhibits superior hydrothermal performance, which could maintain better heat transfer performance while simultaneously reducing the friction factor of minichannels. These findings provide valuable insights for the design of three-dimensional pin fins minichannels heat sink.

Numerical study on the impact of geometrical parameters and employing ternary hybrid nanofluid on the hydrothermal performance of mini-channel heat sink

Thermal management and temperature control of the electrical, electronic, and electrochemical devices during their operation have always been a challenge for proper performance and further development of them. In this regard, the utilization of liquid-cooled mini-channel heat sinks (MCHSs) and improving their capability for heat dissipation have been considered an effective method in past decades. The current study aims to improve the hydrothermal performance and temperature uniformity of MCHS. To this end, several channel configurations with novel geometrical cross sections, namely basic case and cases 1–4, are designed to investigate the influence of geometrical parameters on the mini-channel performance and temperature distribution inside the heat sink. Moreover, the hydrothermal improvement of each model in comparison to the basic case is computed through a parameter, namely performance evaluation criteria (PEC). Additionally, the impact of employing water-based ternary hybrid nanofluid (THNF) containing TiO2-MgO-GO ternary hybrid nanoparticles (THNPs) with various volume fractions and shape factors (SFs) instead of distilled water in the mini-channel with optimized hydrothermal behavior is thoroughly scrutinized. the outcomes endorse that in case 3 with trapezoidal geometry and PEC parameter equal to 1.2, the Nusselt number improves by 3.2 and 1.3 times, in comparison to case 2 (lowest values of Nusselt number) and base case, at Reynolds number of 831. Also, this is observed that hydraulic diameter directly impacts the pressure drop, and by decrement of that, the pressure drop heightens. However, case 2 with a rhombus geometry results in better temperature uniformity due to its larger effective heat transfer area. Furthermore, it is observed that the volume fraction and SF of THNP significantly affect the hydrothermal behavior of THNF inside the MCHS. For instance, by employing THNF with volume fractions of 0.03 % and 0.05 %, the average heat transfer coefficient (HTC) improves by 9 % and 17 %, pressure drop increases by 220 Pa and 370 Pa, and thermal resistance reduces by 9 % and 25 %, respectively, at Reynolds number of 1496, compared to distilled water. Further, THNF with a volume fraction of 0.05 %, reduces the maximum temperature of the heat sink by 3 K in comparison to distilled water, at a Reynolds number of 831. In addition, the utilization of disparate types of THNP with various SF, including spherical (sf = 3), platelets (sf = 5.7), blades (sf = 8.6), and lamina (sf = 16.1576) is examined and disclosed with volume fraction of 0.05 % and SF of 16.1576 instead of 3, HTC roughly elevates by 67 % and thermal resistance decreases by 47 %, at a Reynolds number of 831.

Improving the performance of mini-channel heat sink by using wavy channel and different types of nanofluids

The combination of nano fluid and changing cross-section mini-channel heat sink effects have become a remarkable choice for the use of thermal devices such as miniature electronic devices to be effectively cooled. In this paper, the comparison of three dimensional straight and wavy channel configuration with using different types nano fluids are numerically investigated. The effects of wave amplitude and A particular type of volume fraction of (Copper Oxide CuO, Dimond Al2O3, Iron Oxide Fe3O4, Titanium Oxide TiO2 and Silver Ag-nano fluids are offered. Three amplitudes of waves (0.15 mm, 0.2 mm and 0.25 mm) and Reynold’s number from 200 to 1000 and concentration volume varieties from 0 to 0.075 are used. The effect on thermal resistance, pressures drop, factor of friction of the mini channel is displayed. It is observed that the mini-channel sink's heat transfer efficiency is greatly enhanced compared to the straight channel in an event of adding distilled water as accoolant. The results indicate that nano fluid and wavy mini-channel can boost the heat sink's hydrothermal efficiency and Ag- water nano fluid in term of heat transfer, it outperforms other nanofluids an enhancement in the Nusselt number reached to 54% at concentration volume 0.075.

Numerical investigation on thermal–hydraulic characteristics in a mini-channel with trapezoidal cross-section longitudinal vortex generators

The stringent requirement and rapid increase in heat dissipation for the high heat flux devices have brought great challenges to cooling performance of mini-channel heat sink (MCHS). Longitudinal vortex generator (LVG) is an effective technology for heat transfer enhancement in MCHS. It remains unclear, however, what effects of LVG cross-section on the thermal–hydraulic characteristics of MCHS are. Herein, a new mini-channel with trapezoidal cross-section LVGs is designed, as well as the effects of front width (a), back width (b) and height (h) of trapezoidal cross-section LVG on local and overall thermal–hydraulic characteristics are explored at the Reynolds number (Re) of 347–868 using numerical simulation method. As results, comparing with rectangular cross-section LVG, trapezoidal cross-section LVG mostly brings better thermal performance, and trapezoidal cross-section LVG with a > b generally performs better comprehensive performance. The best comprehensive performance can be achieved as h equivalents to half of channel height. The recommended optimal parameters are a = 0.6 mm, b = 0.3 mm and h = 0.75 mm to obtain the best comprehensive performance, yielding the maximum performance evaluation criterion (PEC) of 1.756 at Re = 543. Furthermore, comparing to previous studies with LVG, the PEC in present study is better at studied range of Re. Overall, the trapezoidal cross-section LVG as a new and effective technology with optimal parameters is conducive to heat transfer enhancement and comprehensive performance improvement in MCHS.

Performance enhancement in minichannel heat sinks using supercritical carbon dioxide (sCO2) as a coolant

Minichannel heat sinks are widely adopted heat dissipation solutions from miniaturized heat flux generating components, such as microprocessors. This paper presents further enhancements in the thermal and hydraulic performance of a minichannel heat sink by employing supercritical carbon dioxide (sCO2) as a coolant. In this study, thermal and hydraulic performance of CO2-cooled minichannel heat sink at three inlet pressures (Pin,CO2) (i.e., 8.0, 10 and 12 MPa)and inlet temperatures (Tin,CO2) ranging between 30∘C−60∘C is compared with a water-cooled minichannel heat sink at inlet conditions (0.1 MPa,30 °C−38 °C). To investigate the performance of the minichannel heat sinks, a conjugate heat transfer model is solved in a commercial code ANSYS-CFX. Whereas the variations in thermo-physical properties of supercritical carbon dioxide (sCO2) are incorporated in ANSYS-CFX through a real gas property (RGP) table. The results reveal a maximum enhancement of 42.13% in average heat transfer coefficient (h¯) for minichannel heat sink using CO2 as a coolant at inlet conditions of 8.0 MPa and34∘C. Similarly, a pressure drop reduction of 55.79% is computed for CO2 as a coolant at corresponding inlet conditions as compared to water-cooled minichannel heat sink. Moreover, the results suggest that replacing water with CO2 as a coolant at higher inlet pressures (Pin,CO2) i.e., 10 MPa and 12 MPacan further reduce pressure drops in the minichannel heat sink by 60.65% and 62.41%, respectively. Apart from the lower base temperatures, performance evaluation criteria (PEC) suggests that the overall performance of the minichannel heat sink using CO2 at 8.0 MPa is roughly enhanced by 2 times as compared to water-cooled minichannel heat sink.

Cooling performance of mini-channel heat sink with water-based nano-PCM emulsion-An experimental study

In this investigation, the cooling characteristics of mini-channel heat sink with the water-based nano-phase change material emulsions are examined experimentally. The n-eicosane nanoparticles and the pure water are considered as the as the phase change material and base fluid, respectively. The fluid flow and convection heat transfer in the mini channel heat sink are studied at different parameter ranges: the volumetric flow rate varied from Q˙ = 60 cm3 min−1 to 600 cm3 min−1, three values of the heat flux imposed on the bottom wall of the heat sinks including qh″ = 3.2 W cm−2, 3.95 W cm−2, and 4.78 W cm−2, and the mass fraction of n-eicosane nanoparticles varied from ωpcm = 0%–10%. The influences of these parameters on the friction factor, wall temperature, heat transfer effectiveness, Nusselt number, figure of merit, coefficient of performance, and thermal resistances are investigated. It is concluded that for the low volumetric flow rate and the heat fluxes of heat flux of 3.20 W cm−2, 3.95 W cm−2, and 4.78 W cm−2, using the n-eicosane nanoparticles with larger values of mass fraction is more proper to decrease the wall temperature. For low value of heat flux, the value of the convective heat transfer effectiveness is larger than unity for most values of Reynolds number. The maximum figure of merit index of 1.098 can be achieved at the Reynolds number of 1381, the heat flux of 4.78 W cm−2, and the mass fraction of 2%. The figure of merit index is decreased with boosting the mass fraction of n–eicosane particles. The figure of merit index is decreased about 44% with boosting the mass fraction of n–eicosane particles from 2% to 10% for the heat flux of 3.20 W cm−2. The usage of n-eicosane nanoparticles with the concentration of 2% results in the lower thermal resistances in comparison to the case of pure water. The difference between the thermal resistances for various mass fractions of n-eicosane nanoparticles decreases as the heat flux increases.

Effect of dual flow arrangements on the performance of mini-channel heat sink: numerical study

Water-cooled heat sinks now gained the popularity due to increased heat generation inside the microprocessor. The generated high heat flux should be removed timely and uniformly for durability of microprocessor. In this work, the thermal performance of mini-channel heat sinks for fin spacing of 0.2 mm, 0.5 mm, 1 mm and 1.5 mm is numerically investigated with various dual flow arrangements. A uniform temperature distribution is observed for all dual flow arrangements discussed in this study which was not possible using single flow inlet/outlet. A direct influence of dual flow arrangements on base temperature and pressure drop of heat sink is evaluated. The results are then compared with the conventional single flow arrangement having same dimensioned heat sink available in the literature for water as well as for Al2O3–H2O nano-fluids. The maximum drop in base temperature was noted for rectangular inlet–circular outlet duct (no gap) flow arrangement as 14.3%, 15.4%, 16.06% and 15.6% for 0.2 mm, 0.5 mm, 1 mm and 1.5 mm fin spacing, respectively, as compared to the conventional single flow arrangement using water as a cooling fluid. Rectangular inlet–circular outlet duct (no gap) was found to be the best dual flow arrangement for all fin spacing investigated. The rectangular collector was then replaced by isosceles triangular collector for the best dual flow arrangement. The maximum reduction in net mass was noted as 12.0%, using isosceles triangular collector as compared to rectangular collector with same thermal performance. Dual rectangular inlet–circular outlet (no gap) flow arrangement highlights palpable improvement in hydrothermal performance compared to the conventional single circular inlet/outlet flow arrangement along with temperature uniformity.

Numerical Investigations of Mini-Channel Heat Sink for Microprocessor Cooling: Effect of Slab Thickness

High heat generation in microelectronics devices is an inevitable consequence of high processing loads. One of the important factors in design of electronic devices is to design a smart cooling system to remove the generated heat well in time for a reliable and longer life. Water-cooled heat sinks are replacing air-cooled heat sinks with the rapid compactness and high process requirements. In this work, we introduced a slab in mini-channel and evaluated the thermal performance of mini-channel heat sink. The boundary layer separately develops in upper and lower portions of channel, which enhanced the heat transfer. We changed the thickness of slab from 0.2 to 1.6 mm for fin spacing of 0.5 mm and 1 mm, respectively, to determine the effects of thickness on overall thermal performance of heat sink. The computed values were then compared with the data available in the literature without slab. The minimum base temperatures recorded for 0.2-mm-thick slab with fin spacing of 0.5 mm and 1.0 mm were 40.1 °C and 42.4 °C, respectively. This represents a reduction of 12.5% and 16.2%, respectively, in the base temperature as compared to the base temperature without a slab.

Numerical investigation of laminar flow and heat transfer in a liquid metal cooled mini-channel heat sink

With the recent trend of miniaturization and high-power output, effective heat dissipation has become the top priority in several industrial applications. This work contributes to the novel and efficient cooling technique that utilizes the liquid metal as working fluid. A numerical analysis of laminar flow and forced convective heat transfer of Galinstan through a mini-channel heat sink exposed to a constant heat flux has been presented. A detailed parametric analysis of the influence of heat sink's geometry, and the inlet velocity on the pressure drop, pumping power and the maximum heat flux has been carried out. Optimized heat sink's dimensions and inlet velocity are obtained. Furthermore, the numerical results are compared with the analytical correlations and discussion concerning the agreement and discrepancy is made. In addition, the flow and heat transfer performance of mini-channel heat sink cooling using liquid metal, nanofluid and water are compared, which intuitively shows the advantage of using liquid metal as coolant.

Effect of different nanoparticle-dispersed nanofluids on hydrothermal-economic performance of minichannel heat sink

Hydrothermal and energy-economic performances of minichannel heat sink are experimentally compared by using water-based different nanoparticle-dispersed mono and hybrid nanofluids. Al2O3, AlN, CNT, Cu and capric acid as phase change material (PCM) are considered. Different nanoparticles combinations (oxide–PCM, oxide–nitride, oxide–carbon nanotube and oxide–metal) in 50/50 volume ratio with water (base fluid) are taken as working fluids. The effects of volume flow rate (0.1–0.5 LPM) or Reynolds number (50 to 500) and total particle volume concentration (0.01–0.1%) are investigated. Convective heat transfer coefficient and pressure drop increase by about 42.3% and 22%, respectively, for Al2O3 + CNT nanofluid. The maximum reduction of 26.6% in thermal resistance is obtained for Al2O3 + CNT nanofluid as compared to base fluid. Heat transfer effectiveness and figure of merit are above one for all the hybrid nanofluids, which conclude that hybrid nanofluid is a better option over base fluid for minichannel heat sink. Al2O3 + CNT hybrid nanofluid is better in terms of heat transfer effectiveness, but Al2O3 + AlN hybrid nanofluid yields higher heat transfer coefficient to pressure drop ratio and coefficient of performance. The lower nanoparticle volume concentration in nanofluid is preferable due to higher stability, lower clogging and lower cost per cooling capacity of heat sink.

Numerical simulation of hydrothermal performance of minichannel heat sink using inclined slotted plate-fins and triangular pins

In the current paper, the effect of an inclined slotted plate-fin mini-channel heat sink with triangular pins on laminar convection heat transfer and fluid flow was numerically investigated using a conjugate heat transfer model. To optimize the hydro-thermal performance of the heat sink, a parametric study on the geometric design of the slots and pins were carried out. The study was performed by varying the height of the inclined slot, the angle of the slot, and the position of the pin with respect to slot leading edge. The Reynolds number was ranged from 100 to 1600. The CFD results showed that the full height slot with an inclination angle of 55° enhanced the Nusselt number and the hydrothermal performance factor (JF) up to 1.5 and 1.43, respectively, in comparison with the simple mini-heat sink. Moreover, the Nusselt number and JF factor of the heat sink with using both slots and pins outperformed the straight channel by about 1.84 and 1.54, respectively.

Parametric study on thermal and hydraulic characteristics of inter-connected parallel and counter flow mini-channel heat sink

The paper presents three-dimensional numerical investigation of fluid flow and heat transfer performance of parallel and counter flow mini-channel heat sink where cross flow between parallel channels was enabled with inter-connectors. The aspect ratio (height to width) and hydraulic diameter of the investigated mini-channel were 0.33 and 750 µm respectively. In this study, water was employed as the coolant, and the flow was in the single-phase regime under laminar flow condition at Reynolds numbers ranging from 150 to 1044. A constant heat flux of 20 W/cm2 was applied at the bottom surface of the heat sink. To analyze the effect of cross flow on the overall thermo-hydraulic performance of the mini-channel heat sink, five different widths of the inter-connector were studied. The non-dimensional pressure, velocity, temperature, friction factor, overall Nusselt number (Nu), and thermal resistance were calculated to evaluate the overall performance of the inter-connected mini-channel heat sink. Finally, the performance of the inter-connected mini channel was compared with the conventional mini-channel by calculating the performance evaluation criteria (PEC). The results show that the inter-connector has a significantly larger effect on the counter flow mini-channel heat sink compared with the parallel flow mini-channel. For the counter flow mini-channel heat sink, Nu was enhanced by a maximum of 36% at Re = 1044 as compared to the conventional parallel flow mini-channel while a maximum of 31.13% reduction in friction factor was recorded at Re = 150. The PEC of the counter flow mini-channel went up to 1.33, and its value shows an increasing trend with as Reynolds number increases.

Experimental performance investigation of minichannel water cooled-thermoelectric refrigerator

An experimental performance analysis of minichannel water cooled-thermoelectric refrigerator in this study is presented. The cooling system of refrigerator is consists of two thermoelectric modules integrated with the minichannel heat sinks in its hot side and the heat dissipaters in its cold side. The experiments carried out for different system voltages and different flow rates of cooling water in the minichannel. The results show that the inner temperature of water cooled-thermoelectric refrigerator is about 2°C for 0.8L/min flow rate while it is about −0.1°C for 1.5L/min flow rate at the end of 2-h experiment. COP value of thermoelectric refrigerator is 0.23 in the flow rate 1.5L/min while COP is 0.19 in the flow rate 0.8L/min at the end of 25min cooling times. When it comes to 8V system voltages, COP of the thermoelectric refrigerator is about 0.41 at the end of 25min operating period for the flow rate 1.5L/min. This study concludes that the performance of minichannel heat sink used in this study has as good as other liquid water cooled systems used to absorb heat from thermoelectric modules hot side.

Influence of Shape, Number, and Position of Horizontal Minifins on Thermal-Hydraulic Performance of Minichannel Heat Sink Using Nanofluid

ABSTRACTIn the first part of present study, an experimental setup with constant heat flux is used to investigate the thermal performance of the water inside a horizontal triangular pin fin channel. For the sake of validation of the computational fluid dynamics (CFD) study, a simulation is conducted according to the geometry and operating conditions of the experimental work. The numerical model consists of a study that has been established based on the geometrical parameters and operating conditions similar to the experimental work. The influence of four different cross sections of minifins (shaped as square, trapezoidal, triangular, and sinusoidal) and of number of triangular minifins (1, 3, 5, 7, and 9) and their positions (in the regions of entrance, central, and terminal) on the heat transfer rate and pressure drop in a minifin minichannel heat sink are numerically investigated by a two-dimensional CFD model. The coolant is Cu–water nanofluid at a volumetric concentration of 2%. The results demonstrated that the sinusoidal minifin minichannel heat sink has the highest convective heat transfer coefficient in comparison with other shapes, while the trapezoidal minifin minichannel showed the highest thermal resistance. The highest pressure drop was observed for the triangular minifin inside minichannel. By increasing the number of fins, thermal resistance considerably decreased. Likewise, at the central and entrance positions, respectively, the highest Nusselt number and friction factor inside the minichannel was observed. This study can provide useful guidelines for the design of the cooling devices.

Experimental study on cooling performance of minichannel heat sink using water-based MEPCM particles

Experimental study was performed to investigate the cooling performance of a minichannel heat sink (Mini-CHS) with microencapsulated phase change material (MEPCM) particles/water as the coolants. Emphasis was focused on the evaluations of the hydraulic and thermal performance of water-based MEPCM particles in a Mini-CHS from the results of friction factor, average Nusselt number, heat transfer efficacy, temperature control effectiveness, and figure of merit with the Reynolds number ranging from 133 to 1515. The measured results reveal that the thermal performance can be enhanced by addition of MEPCM particles in water with low values of latent-sensible heat ratio (ωpcm/Stebf⁎) and using a low flow rate of coolant as compared to those of the pure water. For instance, an increment of 52% heat transfer effectiveness can be achieved for Rebf=133 and ωpcm/Stebf⁎=0.0472. It is also found that the case with lower flow rate and latent-sensible heat ratio has a better improvement of thermal resistance compared with that for the pure water. However, results also indicate that the enhancement effect may be reduced by increasing the values of latent-sensible heat ratio and the thermal performance of the MEPCM particles with higher latent-sensible heat ratio is not necessarily better than that of pure water.