An experimental investigation of the effect of multiple inlet restrictors on the heat transfer and pressure drop in a flow boiling microchannel heat sink

Thermal management at a high heat flux is crucial for high-power electronic devices, and jet impingement cooling is a promising solution. In this paper, a hybrid heat sink combining a microchannel and jet impingement was designed, fabricated and tested in a closed-loop system with R134a as the working fluid. The thermal contact resistance was measured by using the steady-state method, and the thermal resistance of the heat sink was obtained at different heat fluxes and flow rates. The maximum heat dissipation of 400 W/cm2 is achieved on a heater area of 210 mm2, and the thermal resistance of the heat sink is 0.11 K/W with a pressure drop of 13.5 kPa under a flow rate of 1.90 L/min. Low thermal resistance can be achieved for the hybrid heat sink stemming from the highly-dense micro-jet array with separate inflow and outflow microchannels.

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“…The thermal resistance is used to evaluate the cooling performance of the heat sink, which is defined by Equation (10).…”

Section: Data Reduction and Uncertainty Analysismentioning

confidence: 99%

“…In addition to flow instability, bubble clogging and flow reversal are also great challenges with microchannel heat sinks [8,9]. The effects of inlet restrictors (IRs) on heat transfer characteristics were analyzed by Saad et al [10]. Results showed that IRs improved heat transfer characteristics effectively.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Cooling Performance of a Hybrid Microchannel and Jet Impingement Heat Sink

et al. 2022

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“…The thermal and hydraulic performance of microchannels during flow boiling with various inlet restrictor configurations is investigated. [21]. The intake restrictors improve heat transfer performance at high Reynolds numbers while reducing performance at low flow rates.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Heat Transfer and Fluid Flow in a Microchannel Heat Sink with Sidewall Dimples and Fillet Profile

et al. 2022

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“…In addition to water, nanowire-covered microchannels also exhibit improved performance with alternative low-surface tension working fluids such as dielectrics. , Flow boiling enhancements for low-surface tension fluids have also been demonstrated utilizing refrigerants − and surface-altering techniques. , Surface modifications with coatings such as pHEMA, , porous structures, nanocomposites, and carbon nanotubes , have all demonstrated enhanced heat transfer coefficients by up to 180% with a pressure drop penalty up to 20%. Instead of surface modifications, flow boiling instabilities such as temperature and pressure drop fluctuations can also be addressed with inlet restrictors, wherein the cross-sectional area at the channel inlet is reduced . If such surface and geometry modifications are employed while maintaining a low pressure drop, they can lead to highly compact and efficient systems ideal for high-power-density applications.…”

Section: Introductionmentioning

confidence: 99%

“…Instead of surface modifications, flow boiling instabilities such as temperature and pressure drop fluctuations can also be addressed with inlet restrictors, wherein the cross-sectional area at the channel inlet is reduced. 35 If such surface and geometry modifications are employed while maintaining a low pressure drop, they can lead to highly compact and efficient systems ideal for high-powerdensity applications.…”

Section: ■ Introductionmentioning

confidence: 99%

Scalable and Resilient Etched Metallic Micro- and Nanostructured Surfaces for Enhanced Flow Boiling

Upot

Mahvi

Rabbi

et al. 2021

ACS Appl. Nano Mater.

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Flow boiling and evaporation in tubes and channels occur in a wide variety of energy systems, such as refrigeration, air conditioning, power generation, electronics cooling, distillation, and purification. In this work, we demonstrate remarkably increased heat transfer coefficients of 270% during refrigerant flow boiling in scalable microstructured (∼40 μm), industrial-scale (∼1 m long) aluminum (Al) tubes, when compared to smooth unstructured Al tubes. To achieve scalable nanomanufacturing, we create highly conformal and durable structured surfaces by relying on hydrochloric acid Al etching. Flow boiling tests were conducted in 6.35 mm diameter Al tubes using R134a refrigerant as the working fluid. To benchmark our approach and to elucidate the effect of the structure length scale, we also fabricated ultrascalable boehmite (AlO(OH)) nanostructured (∼300 nm) Al tubes, showing that etched microscale features are necessary and key to enhancement. Durability tests conducted using a 28 day long continual flow boiling experiment demonstrated negligible degradation of the etched surfaces. The scalable and cost-effective techniques used to create these durable, etched-Al microstructures may significantly reduce manufacturing cost when contrasted with current enhancement approaches such as extrusion, drawing, and welding.

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An experimental investigation of the effect of multiple inlet restrictors on the heat transfer and pressure drop in a flow boiling microchannel heat sink

Cited by 61 publications

References 24 publications

Experimental Study on Cooling Performance of a Hybrid Microchannel and Jet Impingement Heat Sink

Experimental Study on Cooling Performance of a Hybrid Microchannel and Jet Impingement Heat Sink

Analysis of Heat Transfer and Fluid Flow in a Microchannel Heat Sink with Sidewall Dimples and Fillet Profile

Scalable and Resilient Etched Metallic Micro- and Nanostructured Surfaces for Enhanced Flow Boiling

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