The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Taiho Yeom - One of the best experts on this subject based on the ideXlab platform.
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active heat sink with piezoelectric translational Agitators piezoelectric synthetic jets and micro pin fin arrays
Experimental Thermal and Fluid Science, 2018Co-Authors: Min Zhang, Terrence W Simon, Taiho Yeom, Youmin YuAbstract:Abstract Air-cooled heat sinks are widely used for electronics cooling. Active and passive cooling components can be added to enhance the performance of the air-cooled heat sinks. In this paper, piezoelectric translational Agitators and synthetic jets are integrated as active cooling components while micro pin fins are adopted as a passive cooling scheme. The heat transfer performance of the active heat sink system that combines these active and passive cooling components along with a suction fan is experimentally investigated. The piezoelectric translational Agitators installed within cooling channels are operating at 222 Hz ∼ 820 Hz with a peak-to-peak displacement of 1.0 mm ∼ 1.4 mm, depending on the attached carbon fiber blade type. The piezoelectric synthetic jet array provides impingement flow into the cooling channels with an inclined configuration, that has been successfully integrated into the system without interference with other components by using a wedge platform. The jet operates at 720 Hz with the jet velocity of up to 39 m/s. Micro pin fins are fabricated onto both surfaces of each heat sink channel walls by a double-sided microfabrication technique. They have diameter, height, and spacing of 500 μm, 250 μm, and 1500 μm, respectively. The experimental results indicate that the micro pin fins are most efficient among the employed active and passive cooling components, reducing thermal resistance up to 38%, compared to plain heat sink performance. The piezoelectric translational agitator reduces system thermal resistance by 22%, compared to the non-agitated condition, at the same through-flow rate. The synthetic jet shows weaker cooling capability in the setting tested, compared to enhancement by the agitator plates or pin fins. The active heat sink with the micro pin fins, Agitators, and jets provides a thermal resistance of 0.064 °C/W at 70 CFM (33 L/sec) through-flow of air, about a 48% reduction from that of the non-agitated, plain heat sink under the same operating conditions. The results demonstrate how more effective the active heat sink system is compared to traditional air-cooled heat sinks.
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enhancing heat transfer in air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
International Journal of Heat and Mass Transfer, 2014Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Abstract Air-cooled heat sinks are widely used for microelectronics cooling. Piezoelectrically-driven Agitators and synthetic jets (syn-jets) have been reported as good options in enhancing heat transfer on nearby surfaces. This study proposes that Agitators and syn-jets be integrated within air-cooled heat sinks to significantly augment heat transfer performance. The proposed integration is investigated experimentally and computationally in a single-channel heat sink with one agitator and two syn-jet arrays. The study of a single channel between two fins is a precursor to the design of a full scale, multi-channel heat sink. The agitator and syn-jet arrays are separately driven by three piezoelectric stacks operating at their individual resonant frequencies to actively disrupt and mix the bulk air flow within the channel. The experiments show that the combination of the agitator and syn-jets raises the heat transfer coefficient of the channel by 82.4%, compared with a same channel having channel flow only. The computations show similar rises that agree well with the experiments. The numerical simulations attribute the active heat transfer enhancement to the turbulence introduced in the channel flow near the tips of the fins which constitute the channel walls by the syn-jets and the vortices introduced in the channel flow near the side and base of the channel walls by the agitator plate. Heat transfer enhancement by the agitator and syn-jets increases as their amplitude or frequency increases, but the increase percentage by these active components decreases as the channel flow velocity increases. A correlation between the average Nusselt number for the channel walls and the Reynolds numbers for the channel flow, agitator, and syn-jet is established.
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enhancing heat transfer of air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
ASME 2011 International Mechanical Engineering Congress and Exposition IMECE 2011, 2011Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Air-cooled heat sinks prevail in microelectronics cooling due to their high reliability, low cost, and simplicity. But, their heat transfer performance must be enhanced if they are to compete for high-flux applications with liquid or phase-change cooling. Piezoelectrically-driven Agitators and synthetic jets have been reported as good options in enhancing heat transfer of surfaces close to them. This study proposes that Agitators and synthetic jets be integrated within air-cooled heat sinks to significantly raise heat transfer performance. A proposed integrated heat sink has been investigated experimentally and with CFD simulations in a single channel heat sink geometry with an agitator and two arrays of synthetic jets. The single channel unit is a precursor to a full scale, multichannel array. The agitator and the jet arrays are separately driven by three piezoelectric stacks at their individual resonant frequencies. The experiments show that the combination of the agitator and synthetic jets raises the heat transfer coefficient of the heat sink by 80%, compared with channel flow only. The 3D computations show similar enhancement and agree well with the experiments. The numerical simulations attribute the heat transfer enhancement to the additional air movement generated by the oscillatory motion of the agitator and the pulsating flow from the synthetic jets. The component studies reveal that the heat transfer enhancement by the agitator is significant on the fin side and base surfaces and the synthetic jets are most effective on the fin tips.Copyright © 2011 by ASME
Youmin Yu - One of the best experts on this subject based on the ideXlab platform.
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active heat sink with piezoelectric translational Agitators piezoelectric synthetic jets and micro pin fin arrays
Experimental Thermal and Fluid Science, 2018Co-Authors: Min Zhang, Terrence W Simon, Taiho Yeom, Youmin YuAbstract:Abstract Air-cooled heat sinks are widely used for electronics cooling. Active and passive cooling components can be added to enhance the performance of the air-cooled heat sinks. In this paper, piezoelectric translational Agitators and synthetic jets are integrated as active cooling components while micro pin fins are adopted as a passive cooling scheme. The heat transfer performance of the active heat sink system that combines these active and passive cooling components along with a suction fan is experimentally investigated. The piezoelectric translational Agitators installed within cooling channels are operating at 222 Hz ∼ 820 Hz with a peak-to-peak displacement of 1.0 mm ∼ 1.4 mm, depending on the attached carbon fiber blade type. The piezoelectric synthetic jet array provides impingement flow into the cooling channels with an inclined configuration, that has been successfully integrated into the system without interference with other components by using a wedge platform. The jet operates at 720 Hz with the jet velocity of up to 39 m/s. Micro pin fins are fabricated onto both surfaces of each heat sink channel walls by a double-sided microfabrication technique. They have diameter, height, and spacing of 500 μm, 250 μm, and 1500 μm, respectively. The experimental results indicate that the micro pin fins are most efficient among the employed active and passive cooling components, reducing thermal resistance up to 38%, compared to plain heat sink performance. The piezoelectric translational agitator reduces system thermal resistance by 22%, compared to the non-agitated condition, at the same through-flow rate. The synthetic jet shows weaker cooling capability in the setting tested, compared to enhancement by the agitator plates or pin fins. The active heat sink with the micro pin fins, Agitators, and jets provides a thermal resistance of 0.064 °C/W at 70 CFM (33 L/sec) through-flow of air, about a 48% reduction from that of the non-agitated, plain heat sink under the same operating conditions. The results demonstrate how more effective the active heat sink system is compared to traditional air-cooled heat sinks.
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enhancing heat transfer in air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
International Journal of Heat and Mass Transfer, 2014Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Abstract Air-cooled heat sinks are widely used for microelectronics cooling. Piezoelectrically-driven Agitators and synthetic jets (syn-jets) have been reported as good options in enhancing heat transfer on nearby surfaces. This study proposes that Agitators and syn-jets be integrated within air-cooled heat sinks to significantly augment heat transfer performance. The proposed integration is investigated experimentally and computationally in a single-channel heat sink with one agitator and two syn-jet arrays. The study of a single channel between two fins is a precursor to the design of a full scale, multi-channel heat sink. The agitator and syn-jet arrays are separately driven by three piezoelectric stacks operating at their individual resonant frequencies to actively disrupt and mix the bulk air flow within the channel. The experiments show that the combination of the agitator and syn-jets raises the heat transfer coefficient of the channel by 82.4%, compared with a same channel having channel flow only. The computations show similar rises that agree well with the experiments. The numerical simulations attribute the active heat transfer enhancement to the turbulence introduced in the channel flow near the tips of the fins which constitute the channel walls by the syn-jets and the vortices introduced in the channel flow near the side and base of the channel walls by the agitator plate. Heat transfer enhancement by the agitator and syn-jets increases as their amplitude or frequency increases, but the increase percentage by these active components decreases as the channel flow velocity increases. A correlation between the average Nusselt number for the channel walls and the Reynolds numbers for the channel flow, agitator, and syn-jet is established.
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enhancing heat transfer of air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
ASME 2011 International Mechanical Engineering Congress and Exposition IMECE 2011, 2011Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Air-cooled heat sinks prevail in microelectronics cooling due to their high reliability, low cost, and simplicity. But, their heat transfer performance must be enhanced if they are to compete for high-flux applications with liquid or phase-change cooling. Piezoelectrically-driven Agitators and synthetic jets have been reported as good options in enhancing heat transfer of surfaces close to them. This study proposes that Agitators and synthetic jets be integrated within air-cooled heat sinks to significantly raise heat transfer performance. A proposed integrated heat sink has been investigated experimentally and with CFD simulations in a single channel heat sink geometry with an agitator and two arrays of synthetic jets. The single channel unit is a precursor to a full scale, multichannel array. The agitator and the jet arrays are separately driven by three piezoelectric stacks at their individual resonant frequencies. The experiments show that the combination of the agitator and synthetic jets raises the heat transfer coefficient of the heat sink by 80%, compared with channel flow only. The 3D computations show similar enhancement and agree well with the experiments. The numerical simulations attribute the heat transfer enhancement to the additional air movement generated by the oscillatory motion of the agitator and the pulsating flow from the synthetic jets. The component studies reveal that the heat transfer enhancement by the agitator is significant on the fin side and base surfaces and the synthetic jets are most effective on the fin tips.Copyright © 2011 by ASME
Min Zhang - One of the best experts on this subject based on the ideXlab platform.
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active heat sink with piezoelectric translational Agitators piezoelectric synthetic jets and micro pin fin arrays
Experimental Thermal and Fluid Science, 2018Co-Authors: Min Zhang, Terrence W Simon, Taiho Yeom, Youmin YuAbstract:Abstract Air-cooled heat sinks are widely used for electronics cooling. Active and passive cooling components can be added to enhance the performance of the air-cooled heat sinks. In this paper, piezoelectric translational Agitators and synthetic jets are integrated as active cooling components while micro pin fins are adopted as a passive cooling scheme. The heat transfer performance of the active heat sink system that combines these active and passive cooling components along with a suction fan is experimentally investigated. The piezoelectric translational Agitators installed within cooling channels are operating at 222 Hz ∼ 820 Hz with a peak-to-peak displacement of 1.0 mm ∼ 1.4 mm, depending on the attached carbon fiber blade type. The piezoelectric synthetic jet array provides impingement flow into the cooling channels with an inclined configuration, that has been successfully integrated into the system without interference with other components by using a wedge platform. The jet operates at 720 Hz with the jet velocity of up to 39 m/s. Micro pin fins are fabricated onto both surfaces of each heat sink channel walls by a double-sided microfabrication technique. They have diameter, height, and spacing of 500 μm, 250 μm, and 1500 μm, respectively. The experimental results indicate that the micro pin fins are most efficient among the employed active and passive cooling components, reducing thermal resistance up to 38%, compared to plain heat sink performance. The piezoelectric translational agitator reduces system thermal resistance by 22%, compared to the non-agitated condition, at the same through-flow rate. The synthetic jet shows weaker cooling capability in the setting tested, compared to enhancement by the agitator plates or pin fins. The active heat sink with the micro pin fins, Agitators, and jets provides a thermal resistance of 0.064 °C/W at 70 CFM (33 L/sec) through-flow of air, about a 48% reduction from that of the non-agitated, plain heat sink under the same operating conditions. The results demonstrate how more effective the active heat sink system is compared to traditional air-cooled heat sinks.
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enhancing heat transfer in air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
International Journal of Heat and Mass Transfer, 2014Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Abstract Air-cooled heat sinks are widely used for microelectronics cooling. Piezoelectrically-driven Agitators and synthetic jets (syn-jets) have been reported as good options in enhancing heat transfer on nearby surfaces. This study proposes that Agitators and syn-jets be integrated within air-cooled heat sinks to significantly augment heat transfer performance. The proposed integration is investigated experimentally and computationally in a single-channel heat sink with one agitator and two syn-jet arrays. The study of a single channel between two fins is a precursor to the design of a full scale, multi-channel heat sink. The agitator and syn-jet arrays are separately driven by three piezoelectric stacks operating at their individual resonant frequencies to actively disrupt and mix the bulk air flow within the channel. The experiments show that the combination of the agitator and syn-jets raises the heat transfer coefficient of the channel by 82.4%, compared with a same channel having channel flow only. The computations show similar rises that agree well with the experiments. The numerical simulations attribute the active heat transfer enhancement to the turbulence introduced in the channel flow near the tips of the fins which constitute the channel walls by the syn-jets and the vortices introduced in the channel flow near the side and base of the channel walls by the agitator plate. Heat transfer enhancement by the agitator and syn-jets increases as their amplitude or frequency increases, but the increase percentage by these active components decreases as the channel flow velocity increases. A correlation between the average Nusselt number for the channel walls and the Reynolds numbers for the channel flow, agitator, and syn-jet is established.
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enhancing heat transfer of air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
ASME 2011 International Mechanical Engineering Congress and Exposition IMECE 2011, 2011Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Air-cooled heat sinks prevail in microelectronics cooling due to their high reliability, low cost, and simplicity. But, their heat transfer performance must be enhanced if they are to compete for high-flux applications with liquid or phase-change cooling. Piezoelectrically-driven Agitators and synthetic jets have been reported as good options in enhancing heat transfer of surfaces close to them. This study proposes that Agitators and synthetic jets be integrated within air-cooled heat sinks to significantly raise heat transfer performance. A proposed integrated heat sink has been investigated experimentally and with CFD simulations in a single channel heat sink geometry with an agitator and two arrays of synthetic jets. The single channel unit is a precursor to a full scale, multichannel array. The agitator and the jet arrays are separately driven by three piezoelectric stacks at their individual resonant frequencies. The experiments show that the combination of the agitator and synthetic jets raises the heat transfer coefficient of the heat sink by 80%, compared with channel flow only. The 3D computations show similar enhancement and agree well with the experiments. The numerical simulations attribute the heat transfer enhancement to the additional air movement generated by the oscillatory motion of the agitator and the pulsating flow from the synthetic jets. The component studies reveal that the heat transfer enhancement by the agitator is significant on the fin side and base surfaces and the synthetic jets are most effective on the fin tips.Copyright © 2011 by ASME
Mark North - One of the best experts on this subject based on the ideXlab platform.
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enhancing heat transfer in air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
International Journal of Heat and Mass Transfer, 2014Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Abstract Air-cooled heat sinks are widely used for microelectronics cooling. Piezoelectrically-driven Agitators and synthetic jets (syn-jets) have been reported as good options in enhancing heat transfer on nearby surfaces. This study proposes that Agitators and syn-jets be integrated within air-cooled heat sinks to significantly augment heat transfer performance. The proposed integration is investigated experimentally and computationally in a single-channel heat sink with one agitator and two syn-jet arrays. The study of a single channel between two fins is a precursor to the design of a full scale, multi-channel heat sink. The agitator and syn-jet arrays are separately driven by three piezoelectric stacks operating at their individual resonant frequencies to actively disrupt and mix the bulk air flow within the channel. The experiments show that the combination of the agitator and syn-jets raises the heat transfer coefficient of the channel by 82.4%, compared with a same channel having channel flow only. The computations show similar rises that agree well with the experiments. The numerical simulations attribute the active heat transfer enhancement to the turbulence introduced in the channel flow near the tips of the fins which constitute the channel walls by the syn-jets and the vortices introduced in the channel flow near the side and base of the channel walls by the agitator plate. Heat transfer enhancement by the agitator and syn-jets increases as their amplitude or frequency increases, but the increase percentage by these active components decreases as the channel flow velocity increases. A correlation between the average Nusselt number for the channel walls and the Reynolds numbers for the channel flow, agitator, and syn-jet is established.
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enhancing heat transfer of air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
ASME 2011 International Mechanical Engineering Congress and Exposition IMECE 2011, 2011Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Air-cooled heat sinks prevail in microelectronics cooling due to their high reliability, low cost, and simplicity. But, their heat transfer performance must be enhanced if they are to compete for high-flux applications with liquid or phase-change cooling. Piezoelectrically-driven Agitators and synthetic jets have been reported as good options in enhancing heat transfer of surfaces close to them. This study proposes that Agitators and synthetic jets be integrated within air-cooled heat sinks to significantly raise heat transfer performance. A proposed integrated heat sink has been investigated experimentally and with CFD simulations in a single channel heat sink geometry with an agitator and two arrays of synthetic jets. The single channel unit is a precursor to a full scale, multichannel array. The agitator and the jet arrays are separately driven by three piezoelectric stacks at their individual resonant frequencies. The experiments show that the combination of the agitator and synthetic jets raises the heat transfer coefficient of the heat sink by 80%, compared with channel flow only. The 3D computations show similar enhancement and agree well with the experiments. The numerical simulations attribute the heat transfer enhancement to the additional air movement generated by the oscillatory motion of the agitator and the pulsating flow from the synthetic jets. The component studies reveal that the heat transfer enhancement by the agitator is significant on the fin side and base surfaces and the synthetic jets are most effective on the fin tips.Copyright © 2011 by ASME
Terrence W Simon - One of the best experts on this subject based on the ideXlab platform.
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active heat sink with piezoelectric translational Agitators piezoelectric synthetic jets and micro pin fin arrays
Experimental Thermal and Fluid Science, 2018Co-Authors: Min Zhang, Terrence W Simon, Taiho Yeom, Youmin YuAbstract:Abstract Air-cooled heat sinks are widely used for electronics cooling. Active and passive cooling components can be added to enhance the performance of the air-cooled heat sinks. In this paper, piezoelectric translational Agitators and synthetic jets are integrated as active cooling components while micro pin fins are adopted as a passive cooling scheme. The heat transfer performance of the active heat sink system that combines these active and passive cooling components along with a suction fan is experimentally investigated. The piezoelectric translational Agitators installed within cooling channels are operating at 222 Hz ∼ 820 Hz with a peak-to-peak displacement of 1.0 mm ∼ 1.4 mm, depending on the attached carbon fiber blade type. The piezoelectric synthetic jet array provides impingement flow into the cooling channels with an inclined configuration, that has been successfully integrated into the system without interference with other components by using a wedge platform. The jet operates at 720 Hz with the jet velocity of up to 39 m/s. Micro pin fins are fabricated onto both surfaces of each heat sink channel walls by a double-sided microfabrication technique. They have diameter, height, and spacing of 500 μm, 250 μm, and 1500 μm, respectively. The experimental results indicate that the micro pin fins are most efficient among the employed active and passive cooling components, reducing thermal resistance up to 38%, compared to plain heat sink performance. The piezoelectric translational agitator reduces system thermal resistance by 22%, compared to the non-agitated condition, at the same through-flow rate. The synthetic jet shows weaker cooling capability in the setting tested, compared to enhancement by the agitator plates or pin fins. The active heat sink with the micro pin fins, Agitators, and jets provides a thermal resistance of 0.064 °C/W at 70 CFM (33 L/sec) through-flow of air, about a 48% reduction from that of the non-agitated, plain heat sink under the same operating conditions. The results demonstrate how more effective the active heat sink system is compared to traditional air-cooled heat sinks.
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enhancing heat transfer in air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
International Journal of Heat and Mass Transfer, 2014Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Abstract Air-cooled heat sinks are widely used for microelectronics cooling. Piezoelectrically-driven Agitators and synthetic jets (syn-jets) have been reported as good options in enhancing heat transfer on nearby surfaces. This study proposes that Agitators and syn-jets be integrated within air-cooled heat sinks to significantly augment heat transfer performance. The proposed integration is investigated experimentally and computationally in a single-channel heat sink with one agitator and two syn-jet arrays. The study of a single channel between two fins is a precursor to the design of a full scale, multi-channel heat sink. The agitator and syn-jet arrays are separately driven by three piezoelectric stacks operating at their individual resonant frequencies to actively disrupt and mix the bulk air flow within the channel. The experiments show that the combination of the agitator and syn-jets raises the heat transfer coefficient of the channel by 82.4%, compared with a same channel having channel flow only. The computations show similar rises that agree well with the experiments. The numerical simulations attribute the active heat transfer enhancement to the turbulence introduced in the channel flow near the tips of the fins which constitute the channel walls by the syn-jets and the vortices introduced in the channel flow near the side and base of the channel walls by the agitator plate. Heat transfer enhancement by the agitator and syn-jets increases as their amplitude or frequency increases, but the increase percentage by these active components decreases as the channel flow velocity increases. A correlation between the average Nusselt number for the channel walls and the Reynolds numbers for the channel flow, agitator, and syn-jet is established.
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enhancing heat transfer of air cooled heat sinks using piezoelectrically driven Agitators and synthetic jets
ASME 2011 International Mechanical Engineering Congress and Exposition IMECE 2011, 2011Co-Authors: Youmin Yu, Terrence W Simon, Min Zhang, Taiho Yeom, Mark NorthAbstract:Air-cooled heat sinks prevail in microelectronics cooling due to their high reliability, low cost, and simplicity. But, their heat transfer performance must be enhanced if they are to compete for high-flux applications with liquid or phase-change cooling. Piezoelectrically-driven Agitators and synthetic jets have been reported as good options in enhancing heat transfer of surfaces close to them. This study proposes that Agitators and synthetic jets be integrated within air-cooled heat sinks to significantly raise heat transfer performance. A proposed integrated heat sink has been investigated experimentally and with CFD simulations in a single channel heat sink geometry with an agitator and two arrays of synthetic jets. The single channel unit is a precursor to a full scale, multichannel array. The agitator and the jet arrays are separately driven by three piezoelectric stacks at their individual resonant frequencies. The experiments show that the combination of the agitator and synthetic jets raises the heat transfer coefficient of the heat sink by 80%, compared with channel flow only. The 3D computations show similar enhancement and agree well with the experiments. The numerical simulations attribute the heat transfer enhancement to the additional air movement generated by the oscillatory motion of the agitator and the pulsating flow from the synthetic jets. The component studies reveal that the heat transfer enhancement by the agitator is significant on the fin side and base surfaces and the synthetic jets are most effective on the fin tips.Copyright © 2011 by ASME
