Conjugate Heat Transfer and Fluid Flow Modeling for Liquid Microjet Impingement Cooling with Alternating Feeding and Draining Channels

Abstract

Liquid microjet impingement cooling has shown the potential to be the solution for heat removal from electronic devices such as very-large-scale integration (VLSI) chips. The post-impingement dynamics of the jet, specifically the interaction between the liquid fronts on the surface engendered by the jets is a critical criterion improving the heat transfer characteristics. While some seminally important experimental studies have investigated this attribute, the amount of accurate data and analysis is limited by the shortcomings of real-life experiments. In this article, numerical investigations into the fluid dynamics and heat transfer in microjet cooling systems are carried out. Specifically, this paper addresses the question regarding the necessary fidelity of the simulations. Different Reynolds-averaged Navier–Stokes (RANS) models are compared to the Large Eddy Simulations (LES) simulation and the potential fidelity of different eddy-viscosity-based closures is clearly shown. Recommendations are made regarding the RANS closures that should give the best performance. It is demonstrated that the transition Shear Stress Transport (SST) model and k - ω SST model both show excellent ability to predict the local or average Nu, and also local level pressure coefficient f with less than 5% difference in the range of 30 < Red < 4000, compared with the reference LES model. For the experimental measurements in the range of 130 < Red < 1400, the LES model, transition SST model and k - ω SST model all show less than 25% prediction error. Moreover, it is shown that the validity of the unit cell assumption for the temperature and flow distribution depends on the flow rate.

Numerical modelling and analysis of porous surface-enhanced jet cooling using copper inverse opals in single-phase flow

“…Considering that the Reynolds numbers are far lower than the turbulent transition reported in the literature, which is often larger than 1000 (Zuckerman & Lior 2006), the impingement jet is treated as a laminar flow here. To justify the laminar assumption, the critical Reynolds number for the transition from the laminar to the transitional regime is identified with different Reynolds-averaged Navier-Stokes (RANS) models (Wei et al 2019a). As shown in figure 4 Reynolds number is significantly lower than the values for the transitional regime, which are reported to be 375 < Re p < 750 in the literature (Wood, He & Apte 2020).…”

“…Single-phase jet impingement has been established as a promising cooling scheme for highly integrated microdevices, based on both numerical and experimental investigations (Brunschwiler et al 2006;Tang et al 2016;Laguna et al 2018;Patil & Hotta, 2018;Wei et al 2019aWei et al ,b, 2020aWei et al ,b, 2022. Due to the thin hydrodynamic and thermal boundary layers generated by the impingement jet, singlephase liquid impingement jet cooling can achieve a much higher heat transfer coefficient (HTC) than conventional cooling schemes, particularly in the stagnation region.…”

Realistic design of laser powder bed fusion channels

“…For simulations of the second stage of the experiment in the nominal geometry, the k-ω turbulence model was used within a Reynolds-number-Averaged-Navier-Stokes (RANS) simulation, with a uniform wall sand-grain roughness value corresponding to the calculated average roughness. The choice of turbulence model was guided by a recent study on comparison of various turbulence models for impinging flow within cooling applications (Wei et al , 2019), as well as a study highlighting the comparison of RANS and Large Eddy simulations for ribbed cooling passages (Keshmiri et al , 2016). In the case of the deformed geometry, the same RANS simulation was performed without adding any sand-grain roughness to the walls.…”

Numerical study on significance of wave amplitude, wavelength and aspect ratio on heat transfer and fluid flow characteristics in circular wavy MC heat sink design

“…where l is fluid dynamic viscosity T is fluid temperature. From the literature 32,33 it is noticed that LES model required huge computational time than laminar model with smaller variation(less than 5%) in results. To minimize the computational time authors are chosen laminar model in present study.…”