Liquid Cooling Performance of the Single and Multi Led Circuit Boards Used in Automotive Lighting Systems

Author(s):  
Muhsin Kilic ◽  
Mehmet Aktas ◽  
Gokhan Sevilgen
Author(s):  
Özgür Atik ◽  
Hakan Ertürk

Cooling performance enhancement of computer liquid cooling (LC) systems using hexagonal boron nitride (hBN)–water nanofluids is investigated experimentally. Particle volume fractions of 0.1–2% are considered at constant flow rates varying from 0.3 to 2 L/min for two different cold plates (CPs), with and without fins. A commercial closed-loop LC system is also tested to examine performance of hBN–water nanofluids at constant pumping power. It was observed that the thermal performance can be improved by using hBN nanofluids, and higher improvements are achieved for systems with limited convection rates.


2014 ◽  
Vol 6 ◽  
pp. 126301 ◽  
Author(s):  
Yasuo Sakurai ◽  
Takeshi Nakada ◽  
Kazuya Edamura

The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF) is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5312
Author(s):  
Quanyi Li ◽  
Jong-Rae Cho ◽  
Jianguang Zhai

The cooling structure of a battery pack and coupled liquid cooling and phase change material (PCM) were designed in a thermal management system to enhance the cooling performance and extend the service life of lithium-ion battery packs. Numerical simulations were conducted based on the finite volume method. This study focuses on factors such as the layout of the terminal, flow rate of the coolant, different sections of the cooling pipe, position of the cooling pipe, and coupled liquid cooling, and investigates their influences on the operating temperature. The results show that a reasonable terminal layout can reduce heat generation inside the batteries. The appropriate flow rate and position of the cooling pipe effectively reduced the maximum temperature and minimized energy consumption. Then, the PCM was placed between the adjacent batteries near the outlet to enhance the uniformity of the battery pack. The temperature difference was reduced to near 5 K. This study provides a clear direction for improving the cooling performance and extending the service life of battery packs.


2019 ◽  
Vol 52 (3) ◽  
pp. 377-388
Author(s):  
SW Park ◽  
C-S Lee ◽  
HR Kang ◽  
HS Pak ◽  
A Wilkins

Light-emitting diode-based lighting systems are now applied in both general lighting and automotive lighting. Time-modulated control methods such as pulse width modulation are frequently applied as a dimming method. This paper presents the characteristics of the visibility of the phantom array effect according to luminance, chromaticity and angular field of view. The threshold frequency of the visibility of the phantom array increases in proportion to the logarithm of the luminance of the light source. As the angular field of view of the light source increases, the threshold frequency of the visibility of the array decreases exponentially over a range from 0.125° to 4° in our experimental conditions. The threshold frequency at which the array is visible depends on chromaticity at high light source modulation frequencies. When designing time-modulated light sources, our findings can be applied so as to minimize the phantom array effect.


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