Cooling Performance Evaluation of Synthetic Jet Based Thermal Solution Module

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Ahmad Jalilvand ◽  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Yoji Kawahara ◽  
Randeep Singh ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Removal ◽  
Synthetic Jet ◽  
Air Jet ◽  
Convective Thermal ◽  
Thermal Solution ◽  
Pipe Heat

The convective thermal resistance which represents the heat removal from the heat sink surface of a heat pipe/heat sink module to mean coolant flow temperature is often a dominant contributor to the overall thermal resistance of a heat pipe/heat sink module or remote heat exchange (RHE). RHE is a thermal solution module composed of a heat spreader, thin flattened heat pipe with low profile heat sink which is widely used for the thermal management of compact portable electronic devices. Minimizing the convective thermal resistance at the heat sink of RHE as well as thickness reduction is often an important objective for the thermal designers. Recently, an alternate air mover system which operates based on piezoelectricity is developed. This device is called dual cooling jet (DCJ) in short which can be fabricated with very small thickness down to 1.0 mm. Thin DCJ as a synthetic jet generates air jet with more than 7 m/s air flow velocity which is promising for the increasing demands of thinner next generation portable electronic devices. DCJ is a promising device to dissipate the heat from the heat sink of a RHE. In this work, the performance of RHE is evaluated when heat is dissipated from its heat sink by DCJ. The results are compared with conventional rotary fan. The results show that more than 12 W of heat can be dissipated by DCJ which can easily compete with some commercialized rotary mini blowers while having much smaller thickness. Various configuration of heat sink–DCJ combinations as well as size and shape of both heat sink and DCJ are tested and based on thermal resistance data, cooling effectiveness of DCJ is studied.

Design and Thermal Characteristics of a Synthetic Jet Ejector Heat Sink

2004 ◽  
Vol 127 (2) ◽  
pp. 172-177 ◽  
Author(s):  
Raghav Mahalingam ◽  
Ari Glezer
Keyword(s):  
Thermal Resistance ◽  
Steady Flow ◽  
Heat Sink ◽  
Power Dissipation ◽  
Ambient Air ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Transfer Coefficients ◽  
Electromagnetic Actuators ◽  
Air Jet

The design and thermal performance of a synthetic-air-jet-based heat sink for high-power dissipation electronics is discussed. Each fin of a plate-fin heat sink is straddled by a pair of two-dimensional synthetic jets, thereby creating a jet ejector system that entrains cool ambient air upstream of the heat sink and discharges it into the channels between the fins. The jets are created by periodic pressure variations induced in a plenum by electromagnetic actuators. The performance of the heat sink is assessed using a thermal test die encased in a heat spreader that is instrumented with a thermocouple. The case-to-ambient thermal resistance under natural convection with the heat sink is 3.15°C∕W. Forced convection with the synthetic jets enables a power dissipation of 59.2W at a case temperature of 70°C, resulting in a case-to-ambient thermal resistance of 0.76°C∕W. The synthetic-jet heat sink dissipates ∼40% more heat compared to steady flow from a ducted fan blowing air through the heat sink. The synthetic jets generate a flow rate of 4.48 CFM through the heat sink, resulting in 27.8 W/CFM and thermal effectiveness of 0.62. The effect of fin length on the thermal resistance of the heat sink is discussed. Detailed measurements on an instrumented heat sink estimate that the average heat transfer coefficients in the channel flow between the fins is 2.5 times that of a steady flow in the ducts at the same Reynolds Number.

Thermal Characteristics of a Synthetic Jet Integrated Heat Sink Design for Air-Cooled Electronics

2009 ◽  
Author(s):  
Yogen Utturkar ◽  
Mehmet Arik ◽  
Tunc Icoz
Keyword(s):  
Heat Sink ◽  
Low Cost ◽  
Thermal Characteristics ◽  
Heat Removal ◽  
Synthetic Jet ◽  
Air Cooling ◽  
Air Jets ◽  
Trade Offs ◽  
Thermal Solution ◽  
Near Term

Thermal management is currently one of the key limitations in the design of electronic systems. Parallel to the advancements in the electronics industry and increase in power dissipation the development of effective, low-cost, compact heat removal solutions become extremely critical to ensure a failsafe and reliable operation. While liquid cooling is poised to provide the cooling capability for next generation electronics, its use in present-day products is less prevalent due to risks associated with condensation, leakage, and pumping power. Consequently, air-cooling strategies still continue to vie for near-term cooling needs in the electronic industry. In cohort with these trends, an advanced air-cooling solution in form of a synthetic jet assisted heat sink has been investigated in the present study. The study focuses on key design aspect of the heat sink fin design, synthetic jet design and characterization, and the interaction of unsteady air jets with the heat sink fins. Numerical simulations are employed to investigate 3D unsteady flow dynamics and experimental setup is designed and built for validation. The paper systematically presents the design trade-offs associated with the number of jets in the thermal solution and the jet driving conditions (voltage and frequency), in terms of the thermal performance and the cost. Overall, the synthetic jet integrated heat sink has demonstrably been shown to dissipate up to 4.7 times better than conventional natural convection heat sink with a COP value of greater than 40 within a volume of 25 in3.

THERMAL AND HYDRODYNAMIC PERFORMANCE OF A MICROCHANNEL HEAT SINK COOLED WITH CARBON NANOTUBES NANOFLUID

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Nik Ahmad Faiz Nik Mazlam ◽  
Normah Mohd-Ghazali ◽  
Thierry Mare ◽  
Patrice Estelle ◽  
Salma Halelfadl
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Operating Temperature ◽  
Heat Removal ◽  
Hydrodynamic Performance ◽  
Spherical Particles ◽  
Microchannel Heat Sink ◽  
Pumping Power ◽  
Rectangular Microchannel ◽  
Aspect Ratios

The microchannel heat sink (MCHS) has been established as an effective heat removal system in electronic chip packaging. With increasing power demand, research has advanced beyond the conventional coolants of air and water towards nanofluids with their enhanced heat transfer capabilities. This research had been carried out on the optimization of the thermal and hydrodynamic performance of a rectangular microchannel heat sink (MCHS) cooled with carbon nanotube (CNT) nanofluid, a coolant that has recently been discovered with improved thermal conductivity. Unlike the common nanofluids with spherical particles, nanotubes generally come in cylindrical structure characterized with different aspect ratios. A volume concentration of 0.1% of the CNT nanofluid is used here; the nanotubes have an average diameter and length of 9.2 nm and 1.5 mm respectively. The nanofluid has a density of 1800 kg/m3 with carbon purity 90% by weight having lignin as the surfactant. The approach used for the optimization process is based on the thermal resistance model and it is analyzed by using the non-dominated sorting multi-objective genetic algorithm. Optimized outcomes include the channel aspect ratio and the channel wall ratio at the optimal values of thermal resistance and pumping power. The optimized results show that, at high operating temperature of 40°C the use of CNT nanofluid reduces the total thermal resistance by 3% compared to at 20°C and consequently improve the thermal performance of the fluid. In terms of the hydrodynamic performance, the pumping power is also being reduced significantly by 35% at 40°C compared to the lower operating temperature.  

scholarly journals Experimental Investigations of Different Loudspeakers Applied as Synthetic Jet Actuators

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 224
Author(s):  
Paweł Gil ◽  
Joanna Wilk
Keyword(s):  
Thermal Resistance ◽  
Resonance Frequency ◽  
Sound Pressure Level ◽  
Heat Sink ◽  
Sound Pressure ◽  
Pressure Level ◽  
Synthetic Jet ◽  
Experimental Investigations ◽  
Driving Frequency ◽  
Jet Velocity

The paper presents the preliminary results of the experimental investigation of four various loudspeakers used for driving the synthetic jet actuator. The parameters, characteristic synthetic jet velocity, pressure inside the cavity, device sound pressure level (SPL), and the heat sink thermal resistance, were presented for various input power and driving frequency. The resonance frequency was determined based on electrical impedance. The highest synthetic jet momentum velocity was achieved at diaphragm resonance frequency. The maximum sound pressure level was observed, also at resonant frequency. For the same real power delivered to the actuator and for its resonance frequency, the heat sink thermal resistance had the lowest value for the specific loudspeaker. In turn, the synthetic jet velocity reached maximum for this actuator. For all actuators tested, the sound pressure level was dependent on momentum velocity.

Experimental Investigation of Integrated Heat Pipe Heat Sink for Multi-chip LED Module in Natural Convection

2014 ◽  
Vol 35 (11) ◽  
pp. 1394-1400
Author(s):  
周驰 ZHOU Chi ◽  
左敦稳 ZUO Dun-wen ◽  
孙玉利 SUN Yu-li
Keyword(s):  
Experimental Investigation ◽  
Natural Convection ◽  
Heat Pipe ◽  
Heat Sink ◽  
Pipe Heat

scholarly journals Thermal and Flow Characteristics in a Concentric Annular Heat Pipe Heat Sink

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5282
Author(s):  
Eui-Hyeok Song ◽  
Kye-Bock Lee ◽  
Seok-Ho Rhi ◽  
Kibum Kim
Keyword(s):  
Heat Pipe ◽  
Heat Sink ◽  
Flow Characteristics ◽  
Filling Ratio ◽  
Working Fluid ◽  
Internal Working ◽  
Flow Configurations ◽  
Air Flow Velocity ◽  
Different Diameters ◽  
Pipe Heat

A concentric annular heat pipe heat sink (AHPHS) was proposed and fabricated to investigate its thermal behavior. The present AHPHS consists of two concentric pipes of different diameters, which create vacuumed annular vapor space. The main advantage of the AHPHS as a heat sink is that it can largely increase the heat transfer area for cooling compared to conventional heat pipes. In the current AHPHS, condensation takes place along the whole annular space from the certain heating area as the evaporator section. Therefore, the whole inner space of the AHPHS except the heating area can be considered the condenser. In the present study, AHPHSs of different diameters were fabricated and studied experimentally. Basic studies were carried out with a 50 mm-long stainless steel AHPHS with diameter ratios of 1.1 and 1.3 and the same inner tube diameter of 76 mm. Several experimental parameters such as volume fractions of 10–70%, different air flow velocity, flow configurations, and 10–50 W heat inputs were investigated to find their effects on the thermal performance of an AHPHS. Experimental results show that a 10% filling ratio was found to be the optimum charged amount in terms of temperature profile with a low heater surface temperature and water as the working fluid. For the methanol, a 40% filling ratio shows better temperature behavior. Internal working behavior shows not only circular motion but also 3-D flow characteristics moving in axial and circular directions simultaneously.

scholarly journals Integration of a Pulsating Heat Pipe in a Flat Plate Heat Sink

2014 ◽  
Author(s):  
Mitchell P. Hoesing ◽  
Gregory J. Michna
Keyword(s):  
Thermal Resistance ◽  
Flat Plate ◽  
Heat Pipe ◽  
Heat Sink ◽  
New Technologies ◽  
Operating Conditions ◽  
Working Fluid ◽  
High Heat Flux ◽  
Pulsating Heat Pipe ◽  
Plate Heat

The ongoing development of faster and smaller electronic components has led to a need for new technologies to effectively dissipate waste thermal energy. The pulsating heat pipe (PHP) shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. A 20-turn flat plate PHP was integrated into an aluminum flat plate heat sink with a simulated electronic load. The PHP heat sink used water as the working fluid and had 20 parallel channels with dimensions 2 mm × 2 mm × 119 mm. Experiments were run under various operating conditions, and thermal resistance of the PHP was calculated. The performance enhancement provided by the PHP was assessed by comparing the thermal resistance of the heat sink with no working fluid to that of it charged with water. Uncharged, the PHP was found to have a resistance of 1.97 K/W. Charged to a fill ratio of approximately 75% and oriented vertically, the PHP achieved a resistance of .49 K/W and .53 K/W when the condenser temperature was set to 20°C and 30°C, respectively. When the PHP was tilted to 45° above horizontal the PHP had a resistance of .76 K/W and .59 K/W when the condenser was set 20°C and 30°C, respectively. The PHP greatly improves the heat transfer properties of the heat sink compared to the aluminum plate alone. Additional considerations regarding flat plate PHP design are also presented.

Heat Pipe Optimization Team: The Heat Pipe Assisted Heat Sink Project

2004 ◽  
Author(s):  
Damena Agonafer ◽  
Juan Ibarra ◽  
Kendrick McGee ◽  
Frank Platt ◽  
Kendall Harris ◽  
...  
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Heat Sink ◽  
Cell Phone ◽  
Transfer Cell ◽  
Customer Requirements ◽  
High Increase ◽  
Phone Calls ◽  
Thermal Solution ◽  
Base Transceiver Station

The Heat Pipe Assisted Heat Sink (HPAHS) team will be working on solving challenging thermal management problems for a device known as the base transceiver station (BTS); a device used to transfer cell phone calls. This problem was raised due to transfer cell phone calls. This problem was raised due to the high use of cell phone in recent years. According to 2002 Scarborough Research, the number of cell phones in US was 180 million (2/3 of population). Due to this high increase in demand for cell phone usage, Replacement Handset Shipments are projected to increase worldwide from Current 40% of total shipments to almost 85%. This will increase from 211 million in 2002 to 591 million by 2008 (Nokia). Cell phone calls are transferred via a device known as the base transceiver station (BTS). Cell phone companies are increasing the performance of the BTS by adding more electronics. Nokia is increasing the current BTS performance by adding another power amplifier. We will encounter the problem of designing the thermal solution to ensure optimal thermal performance, while meeting customer requirements of cost and manufacturing process.

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