Flow Induced by a Two Stage Electrohydrodynamic Gas Pump in a Square Channel

2021 ◽  
Author(s):  
A.K.M. Monayem Mazumder ◽  
Grace Trombley ◽  
Brendon Cusinio
Keyword(s):  
Two Stage ◽  
Square Channel

Enhanced Forced Convection in a Square Channel With Two-Stage Corona Wind Generator

2012 ◽  
Author(s):  
A. K. M. Monayem H. Mazumder ◽  
F. C. Lai
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Thermal Management ◽  
Forced Convection ◽  
Two Stage ◽  
Maximum Enhancement ◽  
Square Channel ◽  
Wind Generator ◽  
Wide Range ◽  
Corona Wind

In this study, enhancement in forced convection inside a square channel by a two-stage electrohydrodynamic (EHD) gas pump has been examined by numerical simulations. The EHD gas pump with 28 emitting electrodes in each stage has been evaluated for a wide range of operating voltages starting from the corona threshold voltage up to 28 kV for further improvement in its performance over that of a single-stage. To achieve the maximum enhancement in heat transfer, the emitting electrodes of the corona wind generator are flush mounted on the channel walls so that the corona wind produced directly perturbs the boundary layer. The results show that EHD technique has a great potential for applications in thermal management.

EHD-Induced Flow in a Square Channel With Two-Stage Electrodes

2012 ◽  
Author(s):  
A. K. M. Monayem H. Mazumder ◽  
F. C. Lai ◽  
Y.-T. Chou
Keyword(s):  
Maximum Velocity ◽  
Gas Flows ◽  
Transfer Enhancement ◽  
Two Stage ◽  
Square Channel ◽  
Wide Range ◽  
Cooling Fans ◽  
Induced Flow ◽  
Conventional Cooling ◽  
Better Than

In this study flow field inside a square channel with a two-stage electrohydrodynamic (EHD) gas pump has been critically examined by experimental measurement and numerical simulation. The EHD gas pump with 28 emitting electrodes in each stage is tested for a wide range of operating voltages starting from the corona threshold voltage up to 28 kV for further improvement in its performance over that of a single-stage. It has been shown that the two-stage EHD gas pump can produce and sustain gas flows with a maximum velocity of 5 m/s. Its maximum performance of 34 L/s/W is better than that of conventional cooling fans used in personal computers. The implication for its application in thermal management and heat transfer enhancement has also been discussed.

Enhancement in Forced Convection by a Two Stage Corona Wind Generator

2020 ◽  
Author(s):  
A. K. M. Monayem H. Mazumder
Keyword(s):  
Forced Convection ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Temperature Fields ◽  
Two Stage ◽  
Power Requirement ◽  
Maximum Increase ◽  
Square Channel ◽  
Wide Range ◽  
Volume Method

Abstract In this study, forced convection enhancement in a square channel by a two stage electrohydrodynamic (EHD) gas pump is numerically analyzed. This study is implemented for a two stage EHD gas pump with three emitting electrode configurations: 8, 24, and 56 respectively to seek their effectiveness in the enhancement of forced convection and pumping power requirement. The EHD gas pump is evaluated for a wide range of operating voltages starting from 20 kV up to 28 kV. The influence of electric field on the flow and temperature fields is also examined for a wide range of Reynolds numbers. The three-dimensional governing equations for the flow and temperature fields are solved using the finite volume method. The Reynolds numbers (Re) considered in this study varies in a range between 100 and 2000. At Re = 100, a maximum increase of 42% in the average Nusselt number is achieved with an applied voltage of 28 kV. The overall effectiveness of the EHD gas pump in heat transfer enhancement is evaluated by the thermal hydraulic performance parameter, (Nu/Nu0)/(f/f0), which is always greater than unity. These results disclose that EHD technique has a great potential for many engineering applications, particularly for thermal management.

Flow Induced by a Two Stage Electrohydrodynamic Gas Pump in a Square Channel

2020 ◽  
Author(s):  
A. K. M. Monayem H. Mazumder ◽  
Grace S. Trombley ◽  
Brendon G. Cusinio
Keyword(s):  
Velocity Profile ◽  
Cross Sections ◽  
Volume Flow Rate ◽  
Forced Flow ◽  
Tube Length ◽  
Two Stage ◽  
Maximum Enhancement ◽  
Square Channel ◽  
Parabolic Velocity Profile ◽  
Wide Range

Abstract In this study, fluid flow induced by a two stage electrohydrodynamic (EHD) gas pump in a square channel has been evaluated by experimental measurement and numerical simulations. This study is implemented for a two stage EHD gas pump with three emitting electrode configurations: 8, 24, and 56 respectively to seek the relation between the number of stages and emitting electrodes. The EHD pump is evaluated for a wide range of operating voltages starting from 20 kV up to 28 kV for further improvement in its performance over a single stage. To achieve the maximum enhancement, the emitting electrodes of the EHD gas pump are flush mounted on the channel walls so that the corona wind produced directly disturbs the boundary layer thickness and improves the heat transfer. This is leading to a higher velocity near the channel walls and resulting in an inverted parabolic velocity profile at the center of the channel, which is opposite to the fully developed velocity profile of a forced flow. Velocities are measured at three cross-sections along the tube length and then integrated to obtain the volume flow rate. The results show that EHD technique has a great potential for many engineering applications.

Two-stage self-seeding method for preparation of single crystals of poly(phenylene sulfide)

1989 ◽  
Vol 47 ◽  
pp. 368-369
Author(s):  
Sengshiu Chung ◽  
Peggy Cebe
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Dilute Solution ◽  
Two Stage ◽  
Annealing Behavior ◽  
High Performance Polymers ◽  
Seeding Method ◽  
Phenylene Sulfide

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.

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