Single-Phase and Two-Phase Hybrid Cooling Schemes for High-Heat-Flux Thermal Management of Defense Electronics

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Myung Ki Sung ◽  
Issam Mudawar
Keyword(s):  
Single Phase ◽  
Heat Dissipation ◽  
Jet Impingement ◽  
High Heat ◽  
High Heat Flux ◽  
Microchannel Flow ◽  
Two Phase ◽  
Cooling Performance ◽  
Hybrid Cooling ◽  
Circular Jets

This study examines the cooling performance of two hybrid cooling schemes that capitalize on the merits of both microchannel flow and jet impingement to achieve the high cooling fluxes and uniform temperatures demanded by advanced defense electronics. The jets supply HFE 7100 liquid coolant gradually into each microchannel. The cooling performances of two different jet configurations, a series of circular jets and a single slot jet, are examined both numerically and experimentally. The single-phase performances of both configurations are accurately predicted using 3D numerical simulation. Numerical results point to complex interactions between the jets and the microchannel flow, and superior cooling performance is achieved by optimal selection of microchannel height. The two-phase cooling performance of the circular-jet configuration is found superior to that of the slot jet, especially in terms of high-flux heat dissipation. Unprecedented cooling fluxes, as high as 1127 W/cm2, are achieved with the circular jets without incurring CHF.

scholarly journals Visualization Study of Startup Modes and Operating States of a Flat Two-Phase Micro Thermosyphon

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2291 ◽  
Author(s):  
Liangyu Wu ◽  
Yingying Chen ◽  
Suchen Wu ◽  
Mengchen Zhang ◽  
Weibo Yang ◽  
...  
Keyword(s):  
Wall Temperature ◽  
Large Amplitude ◽  
Small Amplitude ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
High Heat ◽  
High Heat Flux ◽  
Two Phase ◽  
Interface Evolution ◽  
Visualization Experiment

The flat two-phase thermosyphon has been recognized as a promising technique to realize uniform heat dissipation for high-heat-flux electronic devices. In this paper, a visualization experiment is designed and conducted to study the startup modes and operating states in a flat two-phase thermosyphon. The dynamic wall temperatures and gas–liquid interface evolution are observed and analyzed. From the results, the sudden startup and gradual startup modes and three quasi-steady operating states are identified. As the heat load increases, the continuous large-amplitude pulsation, alternate pulsation, and continuous small-amplitude pulsation states are experienced in sequence for the evaporator wall temperature. The alternate pulsation state can be divided into two types of alternate pulsation: lengthy single-large-amplitude-pulsation alternated with short multiple-small-amplitude-pulsation, and short single-large-amplitude-pulsation alternated with lengthy multiple-small-amplitude alternate pulsation state. During the continuous large-amplitude pulsation state, the bubbles were generated intermittently and the wall temperature fluctuated cyclically with a continuous large amplitude. In the alternate pulsation state, the duration of boiling became longer compared to the continuous large-amplitude pulsation state, and the wall temperature of the evaporator section exhibited small fluctuations. In addition, there was no large-amplitude wall temperature pulsation in the continuous small-amplitude pulsation state, and the boiling occurred continuously. The thermal performance of the alternate pulsation state in a flat two-phase thermosyphon is inferior to the continuous small-amplitude pulsation state but superior to the continuous large-amplitude pulsation state.

scholarly journals MODELING MATEMATIS DAN SIMULASI DROPLET UNTUK PENDINGINAN ALAT-ALAT TEKNOLOGI INFORMASI DAN KOMPUTER DENGAN METODE LATTICE-BOLTZMANN

2021 ◽  
Vol 3 (3) ◽  
pp. 389-393
Author(s):  
Wiji Nurastuti ◽  
Kumara Ari Yuana
Keyword(s):  
Single Phase ◽  
Cooling System ◽  
High Heat ◽  
High Heat Flux ◽  
Liquid Cooling ◽  
Computational Stability ◽  
Two Phase ◽  
Fluid Convection ◽  
Spurious Currents ◽  
Multi Phase

Abstrak : Kebutuhan inovasi skema pendinginan untuk pemeliharaan perangkat elektronik dengan suhu aman dibawah batas yang telah ditentukan oleh batasan material dan kendala realibilitas yang terkait pada miniaturisasi microchip yang agresif pada komponen elektronik. Pergeseran dari ketergantungan pada sistem berpendingin kipas menjadi ke skema pendinginan yang memanfaatkan pendingin cairan dielektrik menggunakan berbagai skema pendinginan fase tunggal. Perekayasa (engineer) sistem pendingin memusatkan perhatian pada skema pendinginan dua fase, untuk memanfaatkan kedua system pendingin. Sifat yang harus dimiliki perekayasa sistem pendingin ini yaitu konveksi fluida dan panas laten untuk memindahkan jumlah kalor yang jauh lebih besar dari pada skema fase tunggal, sambil mempertahankan suhu perangkat yang lebih rendah. Beberapa skema pendingin cairan dua fase telah direkomendasikan untuk menghilangkan fluks kalor tinggi dari perangkat yang digunakan diaplikasi. Momentum droplet memungkinkan cairan menembus penghalang uap yang dibuat oleh gelembung nukleasi dan secara lebih efektif mengisi kembali permukaan, keduanya sangat bermanfaat untuk pendinginan fluks tinggi. Pada model dan simulasi pengembangan droplet menggunakan metode LBM multi fase, parameter penting yang selalu didapatkan adalah arus semu maksimum (maximum spurious currents) yang menetukan stabilitas komputasi. Kata kunci : Modeling Matematis, Simulasi Droplet, Metode Latice-Boltzman   Abstract: The need for innovative cooling schemes for maintaining electronic devices with safe temperatures below predetermined limits by material limitations and reliability constraints associated with aggressive microchip miniaturization of electronic components. Shifting from reliance on fan-cooled systems to cooling schemes that utilize dielectric liquid cooling using a variety of single-phase cooling schemes. The cooling system engineer focuses on two-phase cooling schemes, to take advantage of both cooling systems. Properties that these cooling system engineers must possess are fluid convection and latent heat to transfer a much greater amount of heat than a single-phase scheme, while maintaining a lower device temperature. Several two-phase liquid cooling schemes have been recommended to remove the high heat flux from the apparatus used in the application. The droplet momentum allows the liquid to penetrate the vapor barrier created by the nucleation bubbles and more effectively replenish the surface, both of which are very beneficial for high flux cooling. In droplet development models and simulations using the multi-phase LBM method, an important parameter that is always obtained is the maximum spurious currents which determine the computational stability. Keywords: Mathematical Modeling, Droplet Simulation, Latice-Boltzman Method  

Reliable MOSFET operation using two-phase microfluidics in the presence of high heat flux transients

2011 ◽  
Vol 21 (10) ◽  
pp. 105002 ◽  
Author(s):  
Shiv Govind Singh ◽  
Amit Agrawal ◽  
Siddhartha P Duttagupta
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
High Heat Flux ◽  
Two Phase

Model Predictive Control of a Pumped Two-Phase Cooling System With Microchannel Heat Exchangers

2018 ◽  
Author(s):  
Oyuna Angatkina ◽  
Andrew Alleyne
Keyword(s):  
Heat Flux ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Heat Exchangers ◽  
Cooling System ◽  
High Heat ◽  
High Heat Flux ◽  
Two Phase ◽  
Cooling Systems ◽  
Two Phase Cooling

Two-phase cooling systems provide a viable technology for high–heat flux rejection in electronic systems. They provide high cooling capacity and uniform surface temperature. However, a major restriction of their application is the critical heat flux condition (CHF). This work presents model predictive control (MPC) design for CHF avoidance in two-phase pump driven cooling systems. The system under study includes multiple microchannel heat exchangers in series. The MPC controller performance is compared to the performance of a baseline PI controller. Simulation results show that while both controllers are able to maintain the two-phase cooling system below CHF, MPC has significant reduction in power consumption compared to the baseline controller.

Sign in / Sign up

Export Citation Format

Share Document