scholarly journals Effect of liquid cooling on PCR performance with the parametric study of cross-section shapes of microchannels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yousef Alihosseini ◽  
Mohammad Reza Azaddel ◽  
Sahel Moslemi ◽  
Mehdi Mohammadi ◽  
Ali Pormohammad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Heat Sink ◽  
Evaluation Criteria ◽  
Circular Cross Section ◽  
Microchannel Heat Sink ◽  
Liquid Cooling ◽  
Maximum Heat ◽  
Maximum Heat Transfer

AbstractIn recent years, PCR-based methods as a rapid and high accurate technique in the industry and medical fields have been expanded rapidly. Where we are faced with the COVID-19 pandemic, the necessity of a rapid diagnosis has felt more than ever. In the current interdisciplinary study, we have proposed, developed, and characterized a state-of-the-art liquid cooling design to accelerate the PCR procedure. A numerical simulation approach is utilized to evaluate 15 different cross-sections of the microchannel heat sink and select the best shape to achieve this goal. Also, crucial heat sink parameters are characterized, e.g., heat transfer coefficient, pressure drop, performance evaluation criteria, and fluid flow. The achieved result showed that the circular cross-section is the most efficient shape for the microchannel heat sink, which has a maximum heat transfer enhancement of 25% compared to the square shape at the Reynolds number of 1150. In the next phase of the study, the circular cross-section microchannel is located below the PCR device to evaluate the cooling rate of the PCR. Also, the results demonstrate that it takes 16.5 s to cool saliva samples in the PCR well, which saves up to 157.5 s for the whole amplification procedure compared to the conventional air fans. Another advantage of using the microchannel heat sink is that it takes up a little space compared to other common cooling methods.

scholarly journals Thermohydraulic Performance of a Series of In-Line Noncircular Ducts in a Parallel Plate Channel

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Siddharth D. Mhaske ◽  
Soby P. Sunny ◽  
Sachin L. Borse ◽  
Yash B. Parikh
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Parallel Plate ◽  
Circular Cross Section ◽  
Flow Characteristics ◽  
Ansys Fluent ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Plate Channel

Heat transfer and fluid flow characteristics for two-dimensional laminar flow at low Reynolds number for five in-line ducts of various nonconventional cross-sections in a parallel plate channel are studied in this paper. The governing equations were solved using finite-volume method. Commercial CFD software, ANSYS Fluent 14.5, was used to solve this problem. A total of three different nonconventional, noncircular cross-section ducts and their characteristics are compared with those of circular cross-section ducts. Shape-2 ducts offered minimum flow resistance and maximum heat transfer rate most of the time. Shape-3 ducts at Re < 100 and Shape-2 ducts at Re > 100 can be considered to give out the optimum results.

Asymptotic and Exact Analysis for Constructal Optimization of Microchannel Heat Sink

2008 ◽  
Author(s):  
Omid Asgari ◽  
Mohammad Hassan Saidi
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Channel ◽  
Channel Cross Section ◽  
Geometrical Parameters ◽  
Approximate Methods ◽  
Maximum Heat ◽  
Circular Duct ◽  
Maximum Heat Transfer

Microchannel are at the fore front of today’s cooling technologies. They are widely being considered for cooling of electronic devices and in micro heat exchanger systems due to their ease of manufacture. One issue which arises in the use of microchannels is related to the small length scale of the channel or channel cross-section. In this work, the maximum heat transfer and the optimum geometry for a given pressure loss have been calculated for forced convective heat transfer in microchannels of various cross-section having finite volume for laminar flow conditions. Solutions are presented for 10 different channel cross sections, namely parallel plate channel, circular duct, rectangular channel, elliptical duct, polygonal ducts, equilateral triangular duct, isosceles triangular duct, right triangular duct, rhombic duct and trapezoidal duct. The model is only a function of Prandtl number and geometrical parameters of the cross-section, i.e., area and perimeter. This solution is performed with two exact and approximate methods. Finally, in addition to comparison and discussion about these two methods, validation of the relationship is provided using results from the open literature.

Forced Convection in a Microchannel Heat Sink Using Carbon Nanotubes for Heat Transfer Enhancement

2004 ◽  
Author(s):  
Blake E. Jakaboski ◽  
Yogendra Joshi ◽  
Michael Rightley
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Cross Section ◽  
Heat Sink ◽  
Infrared Camera ◽  
Open Loop ◽  
Microchannel Heat Sink ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Multi Walled Carbon Nanotubes

A new type of microchannel heat sink has been developed and evaluated in this study. The device consists of silicon microchannels on whose bottom surfaces multi-walled carbon nanotubes are grown. The objective of the study is to investigate the effect of carbon nanotubes on the heat transfer characteristics. The heat sink size is 15 mm × 15 mm × 0.675 mm. It contains two microchannel designs. One consists of eight channels of cross section 682 μm × 50 μm; the other has six channels of cross section 942 μm × 50 μm. The heat sink is incorporated in an open loop flow facility, with water as the coolant. Six different configurations are compared. Two have no nanotubes, two have closely spaced nanotube, while the last two designs have widely spaced nanotubes. The tests utilize an infrared camera as well as thermocouples placed in the flow for characterization. The heat transfer characteristics are compared for the different cases.

Numerical and Experimental Investigations on Heat Transfer Phenomena of an Aluminium Microchannel Heat Sink

2011 ◽  
Vol 145 ◽  
pp. 129-133 ◽  
Author(s):  
Thanhtrung Dang ◽  
Ngoctan Tran ◽  
Jyh Tong Teng
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Sink ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Microchannel Heat Sink ◽  
Maximum Heat

The study was done both numerically and experimentally on the heat transfer behaviors of a microchannel heat sink. The solver of numerical simulations (CFD - ACE+software package) was developed by using the finite volume method. This numerical method was performed to simulate for an overall microchannel heat sink, including the channels, substrate, manifolds of channels as well as the covered top wall. Numerical results associated with such kinds of overall microchannel heat sinks are rarely seen in the literatures. For cases done in this study, a heat flux of 9.6 W/cm2was achieved for the microchannel heat sink having the inlet temperature of 25 °C and mass flow rate of 0.4 g/s with the uniform surface temperature of bottom wall of the substrate of 50 °C; besides, the maximum heat transfer effectiveness of this device reached 94.4%. Moreover, in this study, when the mass flow rate increases, the outlet temperature decreases; however, as the mass flow rate increases, the heat flux of this heat sink increases also. In addition, the results obtained from the numerical analyses were in good agreement with those obtained from the experiments as well as those from the literatures, with the maximum discrepancies of the heat fluxes estimated to be less than 6 %.

Two-Phase Performance of a Hybrid Jet Plus Multipass Microchannel Heat Sink

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Shailesh N. Joshi ◽  
Danny J. Lohan ◽  
Ercan M. Dede
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Rate ◽  
Heat Sink ◽  
Maximum Pressure ◽  
Microchannel Heat Sink ◽  
Large Area ◽  
Two Phase ◽  
Maximum Heat ◽  
Flow Rates

Abstract The heat transfer and fluid flow performance of a hybrid jet plus multipass microchannel heat sink in two-phase operation is evaluated for the cooling of a single large area, 3.61 cm2, heat source. The two-layer branching microchannel heat sink is evaluated using HFE-7100 as the coolant at three inlet volumetric flow rates of 150, 300, and 450 ml/min. The boiling performance is highest for the flow rate of 450 ml/min with the maximum heat flux value of 174 W/cm2. Critical heat flux (CHF) was observed at two of the tested flow rates, 150 and 300 ml/min, before reaching the maximum operating temperature for the serpentine heater. At 450 ml/min, the heater reached the maximum allowable temperature prior to observing CHF. The maximum pressure drop for the heat sink is 34.1 kPa at a heat flux of 164 W/cm2. Further, the peak heat transfer coefficient value of the heat sink is 28,700 W/m2 K at a heat flux value of 174 W/cm2 and a flow rate of 450 ml/min. Finally, a validated correlation of the single device cooler is presented that predicts heat transfer performance and can be utilized in the design of multidevice coolers.

Cooling Performances of Perforated-Finned Heat Sinks

2016 ◽  
Author(s):  
Mohammad Reza Shaeri ◽  
Bradley Richard ◽  
Richard Bonner
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Sink ◽  
Cooling System ◽  
Thermal Characteristics ◽  
Heat Sinks ◽  
Pumping Power ◽  
Maximum Heat ◽  
Maximum Heat Transfer

Cooling performances of perforated-finned heat sinks (PFHS) are investigated in the laminar forced convection heat transfer mode, through detailed experiments. Perforations like windows with square cross sections are placed on the lateral surfaces of the fins. Cooling performances are evaluated due to changes in both porosities and perforation sizes. Thermal characteristics are reported based on pumping power, in order to provide more practical insight about performances of PFHSs in real applications. It is found that at a constant perforation size, there is an optimum porosity that results in the largest heat transfer coefficient. For a fixed porosity, increasing the number of perforations (reducing the perforation size) results in an enhancement of heat transfer rate due to repeated interruption of the thermal boundary layer. The opposite trend is observed for PFHSs with larger perforation sizes. This indicates that there is an optimum perforation size and distance between perforations in order to achieve the maximum heat transfer coefficients at a constant porosity. Also, a PFHS results in a smaller temperature non-uniformity across the heat sink base, as well as a more rapid reduction in temperature non-uniformity on the heat sink base by increasing pumping power. In addition, the advantage of a PFHS to reduce the overall weight of the cooling system is incorporated into thermal characteristics of the heat sinks, and demonstrated by the mass specific heat transfer coefficient.

Improvement of Thermal Performance of Pin Fin Heat Sink Using Different Types of Perforations: A Study Under Natural Convection

2019 ◽  
Author(s):  
Aashish Kumar ◽  
Manoj Kumar Mondal
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Heat Sink ◽  
Transfer Rate ◽  
Coefficient Of Performance ◽  
Reduced Pressure ◽  
Maximum Heat ◽  
Transfer Rates ◽  
Pin Fin ◽  
Maximum Heat Transfer

Abstract Improvement of thermal management can significantly enhance the coefficient of performance (COP) of the thermoelectric (TE) system which is one of the potential solutions for cooling electronic components. Since heat sinks are an integral part of all the electronic equipment, therefore, great consideration is given towards meticulous selection of heat sink for improving its reliability and performance. Various methods are being studied to improve heat transfer rates of heat sink such as microchannel, liquid cooling, nano-fluids, fin topology optimization, anodization of pins, and changing heat sink materials. Recent studies have demonstrated that perforations in pins increase the heat transfer rate of pin fin heat sink, though, the results are inadequate to infer the best geometry. Further research is hence necessary to establish the best possible combination of geometry, size, and number of perforations. The present work aims to numerically identify a heat sink configuration with maximum heat transfer rate among several configuration possibilities under laminar flow condition using ANSYS Fluent 18.2. The simulation results demonstrate that lateral perforation in fins enable higher heat transfer rate than the unmodified heat sink geometry, due to higher Nusselt number and reduced pressure drop. The parametric study also reveals that heat sink with three elliptical perforations boost heat transfer rates (about 21% higher) when compared to heat sink with solid and other perforated geometries. Furthermore, perforations reduce weight and greater effectiveness, making it more desirable for its wide-scale applications.

Thermo-Fluidic Characteristics in a Cross-Linked Silicon Microchannel Heat Sink

2007 ◽  
Author(s):  
R. Muwanga ◽  
I. Hassan
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cross Sections ◽  
Heat Sink ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Working Fluid ◽  
Microchannel Heat Sink ◽  
Significant Difference ◽  
The Cross

This paper presents the flow and heat transfer characteristics in a cross-linked silicon microchannel heat sink. The heat sink is composed of 45 channels, 270 μm wide × 285 μm tall in a silicon substrate formed via deep reactive ion etching. A detailed discussion of the pressure drop data reduction is described, including characterization of the channel cross-sections and methods to account for inlet and exit loss coefficients. No significant difference is observed in the pressure drop measurements between the cross-linked and standard heat sinks flowing air and water. The use of un-encapsulated liquid crystal thermography was successfully utilized to obtain local heat transfer data with FC-72 as the working fluid. The heat transfer results show inflections in the thermal profile due to the cross-links.

Sign in / Sign up

Export Citation Format

Share Document