This paper presents the design,optimization and fabrication of an EHD air pump intended for high-power electronic chip cooling applications.Suitable high-voltage electrode configurations were selected and studied,in t...This paper presents the design,optimization and fabrication of an EHD air pump intended for high-power electronic chip cooling applications.Suitable high-voltage electrode configurations were selected and studied,in terms of the characteristics of the generated electric field,which play an important role in ionic wind flow.For this purpose,dedicated software is used to implement finite element analysis.Critical design parameters,such as the electric field intensity,wind velocity,current flow and power consumption are investigated.Two different laboratory prototypes are fabricated and their performances experimentally assessed.This procedure leads to the fabrication of a final prototype,which is then tested as a replacement of a typical fan for cooling a high power density electronic chip.To assist towards that end,an experimental thermal testing setup is designed and constructed to simulate the size of a personal computer’s CPU core of variable power.The parametric study leads to the fabrication of experimental single-stage EHD pumps,the optimal design of which is capable of delivering an air flow of 51 CFM with an operating voltage of 10.5 kV.Finally,the theoretical and experimental results are evaluated and potential applications are proposed.展开更多
The ionic wind has good application prospects in the fields of air flow control and heat transfer enhancement. The key for successful applications is how to improve the velocity and how to increase the active area of ...The ionic wind has good application prospects in the fields of air flow control and heat transfer enhancement. The key for successful applications is how to improve the velocity and how to increase the active area of the ionic wind. This paper designed a needle array-mesh type electrohydrodynamic （EHD） gas pump. The use of needle array electrode where corona discharge started simultaneously could enlarge the active area. The velocity of the ionic wind could increase by placing several single-stage ionic wind generators in series appropriately, called as serial staged generator. The maximum average flow velocity of 16.1 m/s and volumetric flow of 303.5 L/min were achieved at the outlet of a 25-stage gas pump and the conversion efficiency was approximately 2.2%.展开更多
Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is t...Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is to evaluate more advantageous configurations that may be scaled up and further help with development of rotary ionic drones.The propellers are designed with regular pin-emitter electrodes placed coaxially inside a cylindrical collector electrode.When high voltage is applied,propellers spin generating conventional axial thrust which is measured with an electronic scale in a“see-saw”setup.Up to 40 mN thrust was obtained in single propeller RIE at 2600 rpm,0.34 mA,37.5 kV,and an optimal collector electrode diameter of 17 cm.More thrust can be obtained with two and three propellers at constant current per propeller but at a decreased efficiency.Varying the axial propeller-separation showed that propeller-interaction is minimal above 5 cm.Thrust-to-power and thrust-tocurrent ratios were calculated and compared.We experimentally confirm here for the first time that within certain limits,the thrust-to-power variation can be assessed by the propeller kinetic energy-to-power ratio and also by the impedance of the gap(voltage-to-current ratio).A comparison of RIE arrays performance with one,two,and three coaxial propellers and the same total number of propellers per array(six)is also performed.RIE arrays with multi-coaxial propellers can provide larger thrust densities than single-propeller arrays.Also,arrays employing two coaxial propeller unit may be more weight effective.展开更多
Electrohydrodynamics (EHD) has been applied in many areas, such as EHD enhanced heat transfer, EHD pump, electrospray mass spectrometry, electrospray nano- technology, etc. The basic theories underlying these applicat...Electrohydrodynamics (EHD) has been applied in many areas, such as EHD enhanced heat transfer, EHD pump, electrospray mass spectrometry, electrospray nano- technology, etc. The basic theories underlying these applications and a brief review of the EHD advances are presented in this paper. As electrospray is an important branch of EHD, the applications of electrospray are particularly discussed. Finally, this paper gives some suggestions for the future research and development.展开更多
文摘This paper presents the design,optimization and fabrication of an EHD air pump intended for high-power electronic chip cooling applications.Suitable high-voltage electrode configurations were selected and studied,in terms of the characteristics of the generated electric field,which play an important role in ionic wind flow.For this purpose,dedicated software is used to implement finite element analysis.Critical design parameters,such as the electric field intensity,wind velocity,current flow and power consumption are investigated.Two different laboratory prototypes are fabricated and their performances experimentally assessed.This procedure leads to the fabrication of a final prototype,which is then tested as a replacement of a typical fan for cooling a high power density electronic chip.To assist towards that end,an experimental thermal testing setup is designed and constructed to simulate the size of a personal computer’s CPU core of variable power.The parametric study leads to the fabrication of experimental single-stage EHD pumps,the optimal design of which is capable of delivering an air flow of 51 CFM with an operating voltage of 10.5 kV.Finally,the theoretical and experimental results are evaluated and potential applications are proposed.
基金supported by National Natural Science Foundation of China(No.50577053)
文摘The ionic wind has good application prospects in the fields of air flow control and heat transfer enhancement. The key for successful applications is how to improve the velocity and how to increase the active area of the ionic wind. This paper designed a needle array-mesh type electrohydrodynamic （EHD） gas pump. The use of needle array electrode where corona discharge started simultaneously could enlarge the active area. The velocity of the ionic wind could increase by placing several single-stage ionic wind generators in series appropriately, called as serial staged generator. The maximum average flow velocity of 16.1 m/s and volumetric flow of 303.5 L/min were achieved at the outlet of a 25-stage gas pump and the conversion efficiency was approximately 2.2%.
基金supported by a grant of the Romanian Ministry of Education and Research,CCCDI,project number PN-Ⅲ-P2-2.1-PED-2019-3646,within PNCDI Ⅲ.
文摘Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first time.The goal is to evaluate more advantageous configurations that may be scaled up and further help with development of rotary ionic drones.The propellers are designed with regular pin-emitter electrodes placed coaxially inside a cylindrical collector electrode.When high voltage is applied,propellers spin generating conventional axial thrust which is measured with an electronic scale in a“see-saw”setup.Up to 40 mN thrust was obtained in single propeller RIE at 2600 rpm,0.34 mA,37.5 kV,and an optimal collector electrode diameter of 17 cm.More thrust can be obtained with two and three propellers at constant current per propeller but at a decreased efficiency.Varying the axial propeller-separation showed that propeller-interaction is minimal above 5 cm.Thrust-to-power and thrust-tocurrent ratios were calculated and compared.We experimentally confirm here for the first time that within certain limits,the thrust-to-power variation can be assessed by the propeller kinetic energy-to-power ratio and also by the impedance of the gap(voltage-to-current ratio).A comparison of RIE arrays performance with one,two,and three coaxial propellers and the same total number of propellers per array(six)is also performed.RIE arrays with multi-coaxial propellers can provide larger thrust densities than single-propeller arrays.Also,arrays employing two coaxial propeller unit may be more weight effective.
基金This work was supported by the National Natural Science Foundation of China(Grant No.5576022)Chinese Academy of Sciences(Grant No.KJCX-SW-L2)"Sponsor Project on Graduators'Science and Society Practice of Chinese Academy Society".
文摘Electrohydrodynamics (EHD) has been applied in many areas, such as EHD enhanced heat transfer, EHD pump, electrospray mass spectrometry, electrospray nano- technology, etc. The basic theories underlying these applications and a brief review of the EHD advances are presented in this paper. As electrospray is an important branch of EHD, the applications of electrospray are particularly discussed. Finally, this paper gives some suggestions for the future research and development.
