scholarly journals Temperature Uniformity in Cross-Flow Double-Layered Microchannel Heat Sinks

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 143
Author(s):  
Carlo Nonino ◽  
Stefano Savino
Keyword(s):  
Numerical Study ◽  
Cross Flow ◽  
Bottom Layer ◽  
Heat Sinks ◽  
Temperature Uniformity ◽  
Counter Flow ◽  
Microchannel Heat Sinks ◽  
Unequal Number ◽  
Flow Configurations ◽  
Header Design

An in-house finite element method (FEM) procedure is used to carry out a numerical study on the thermal behavior of cross-flow double-layered microchannel heat sinks with an unequal number of microchannels in the two layers. The thermal performance is compared with those yielded by other more conventional flow configurations. It is shown that if properly designed, i.e., with several microchannels in the top layer smaller than that in the bottom layer, cross-flow double-layered microchannel heat sinks can provide an acceptable thermal resistance and a reasonably good temperature uniformity of the heated base with a header design that is much simpler than that required by the counter-flow arrangement.

scholarly journals Header Shape Effect on the Inlet Velocity Distribution in Cross-Flow Double-Layered Microchannel Heat Sinks

Fluids ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Stefano Savino ◽  
Carlo Nonino
Keyword(s):  
Velocity Distribution ◽  
Cross Flow ◽  
Flow Distribution ◽  
Thermal Control ◽  
Heat Sinks ◽  
Shape Effect ◽  
Counter Flow ◽  
Ansys Fluent ◽  
Microchannel Heat Sinks ◽  
Header Design

Counter-flow double-layered microchannel heat sinks are very effective for thermal control of electronic components; however, they require rather complicated headers and flow maldistribution can also play a negative role. The cross-flow configuration allows a much simpler header design and the thermal performance becomes similar to that provided by the counter-flow arrangement if the velocity distribution in the microchannels is not uniform. The aim of this work is to show the possibility of achieving a favorable flow distribution in the microchannels of a cross-flow double-layered heat sink with an adequate header design and the aid of additional elements such as full or partial height baffles made of solid or porous materials. Turbulent RANS numerical simulations of the flow field in headers are carried out with the commercial code ANSYS Fluent. The flow in the microchannel layers is modeled as that in a porous material, whose properties are derived from pressure drop data obtained using an in-house FEM code. It is demonstrated that, with an appropriate baffle selection, inlet headers of cross-flow microchannel heat sinks yield velocity distributions very close to those that would allow optimal hotspot management in electronic devices.

Flow Maldistribution Effects on the Temperature Uniformity in Double-Layered Microchannel Heat Sinks

2019 ◽  
Author(s):  
Carlo Nonino ◽  
Stefano Savino
Keyword(s):  
Thermal Resistance ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Total Mass ◽  
Cross Flow ◽  
Heat Sinks ◽  
Temperature Uniformity ◽  
Inlet Velocity ◽  
Microchannel Heat Sinks ◽  
Flow Maldistribution

Abstract A numerical investigation is carried out on the effects of flow maldistribution on the temperature uniformity and overall thermal resistance in double-layered microchannel heat sinks. Different flow maldistribution models accounting for the effects of some typical header designs are considered together with different combinations of the average inlet velocity in the two layers of microchannels for a given total mass flow rate. The numerical simulations are carried out using an in-house FEM procedure previously developed by the authors for the analysis of cross-flow microchannel heat exchangers.

scholarly journals Experimental and Numerical Study of Various MT-SOFC Flow Manifold Techniques: Single MT-SOFC Analysis

2013 ◽  
Vol 10 (1) ◽  
Author(s):  
V. Lawlor ◽  
K. Klein ◽  
C. Hochenauer ◽  
S. Griesser ◽  
S. Kuehn ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Study ◽  
Cross Flow ◽  
Solid Oxide ◽  
Counter Flow ◽  
Current Collection ◽  
Fuel Flow ◽  
Cathode Current ◽  
Collection Point ◽  
Sofc Stacks

Standard anode supported micro tubular-solid oxide fuel cell (MT-SOFC) stacks may provide the oxidant, in relation to the fuel, in three different manifold regimes. Firstly, “co-flow” involves oxidant outside the MT-SOFC flowing co-linearly in relation to the fuel inside. Secondly, “counter flow” involves oxidant outside the MT-SOFC flowing counter-linearly in relation to the fuel inside the MT-SOFC. Finally, “cross-flow” involves the oxidant outside the MT-SOFC flowing perpendicular to the fuel flow inside the MT-SOFC. In order to examine the effect of manifold technique on MT-SOFC performance, a combination of numerical simulation and experimental measurements was performed. Furthermore, the cathode current tap location, in relation to the fuel flow, was also studied. It was found that the oxidant manifold and the location of the cathode current collection point on the MT-SOFC tested and modeled had negligible effect on the MT-SOFC's electrical and thermal performance. In this study, a single MT-SOFC was studied in order to establish the measurement technique and numerical simulation implementation as a prerequisite before further test involving a 7 cell MT-SOFC stack.

Optimisation of single and double layer counter flow microchannel heat sinks

2002 ◽  
Vol 22 (14) ◽  
pp. 1569-1585 ◽  
Author(s):  
S.H. Chong ◽  
K.T. Ooi ◽  
T.N. Wong
Keyword(s):  
Double Layer ◽  
Heat Sinks ◽  
Counter Flow ◽  
Microchannel Heat Sinks

scholarly journals Numerical Study of Double-Layered Microchannel Heat Sinks with Different Cross-Sectional Shapes

Entropy ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 16 ◽  
Author(s):  
Daxiang Deng ◽  
Guang Pi ◽  
Weixun Zhang ◽  
Peng Wang ◽  
Ting Fu
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Numerical Study ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Pumping Power ◽  
Cross Sectional ◽  
Prime Concern ◽  
Microchannel Heat Sinks

This work numerically studies the thermal and hydraulic performance of double-layered microchannel heat sinks (DL-MCHS) for their application in the cooling of high heat flux microelectronic devices. The superiority of double-layered microchannel heat sinks was assessed by a comparison with a single-layered microchannel heat sink (SL-MCHS) with the same triangular microchannels. Five DL-MCHSs with different cross-sectional shapes—triangular, rectangular, trapezoidal, circular and reentrant Ω-shaped—were explored and compared. The results showed that DL-MCHS decreased wall temperatures and thermal resistance considerably, induced much more uniform wall temperature distribution, and reduced the pressure drop and pumping power in comparison with SL-MCHS. The DL-MCHS with trapezoidal microchannels performed the worst with regard to thermal resistance, pressure drop, and pumping power. The DL-MCHS with rectangular microchannels produced the best overall thermal performance and seemed to be the optimum when thermal performance was the prime concern. Nevertheless, the DL-MCHS with reentrant Ω-shaped microchannels should be selected when pumping power consumption was the most important consideration.

Experimental and Numerical Study of Transient Electronic Chip Cooling by Liquid Flow in Microchannel Heat Sink

2010 ◽  
Author(s):  
Jingru Zhang ◽  
Tiantian Zhang ◽  
Yogesh Jaluria
Keyword(s):  
Liquid Flow ◽  
Heat Sink ◽  
Single Channel ◽  
Numerical Study ◽  
Numerical Models ◽  
Heat Removal ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Chip Cooling ◽  
Microchannel Heat Sinks

Cooling of electronic chips has become a critical aspect in the development of electronic devices. Overheating may cause the malfunction or damage of electronics and the time needed for heat removal is important. In this paper, an experimental setup and numerical model was developed to test the effects of different parameters and their influence on the transient electronic chip cooling by liquid flow in microchannel heat sinks. The temperature change with time of the system for different heat fluxes at different flow was determined, from which the response time can be obtained. Three different configurations of multi-microchannel heat sinks were tested during the experiment. Numerical models were then developed to simulate the transient cooling for two of the configurations. A good agreement between the experimental data and numerical results showed that single-channel models are capable of simulating the thermal behavior of the entire heat sink by applying appropriate assumptions and boundary conditions.

Sign in / Sign up

Export Citation Format

Share Document