Investigation of EHD-Enhanced Water Evaporation and a Novel Empirical Model

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
De-Jiang Zheng ◽  
Yong-Qiang Cheng ◽  
Hong-Jiang Liu ◽  
Li-Te Li
Keyword(s):  
Electric Field ◽  
Empirical Model ◽  
Evaporation Rate ◽  
Single Point ◽  
Radial Distance ◽  
Water Evaporation ◽  
Electrode Gap ◽  
Dependence Relation ◽  
Plane Electrode ◽  
Point Electrode

This paper investigates the relationship between the enhanced evaporation rate by electric field, applied voltage (U) and electrode gap (d) in electrohydrodynamics-enhanced water evaporation. The electric fields produced by a single point-to-plane electrode configuration are used. In our experiments, the enhanced evaporation rate by electric field has shown increasing linearly with the U/d ratio. As regard the evaporation rate distribution on the plane electrode, the maximum evaporation rate is observed at the center of the plane (i.e., directly under the point electrode), and significantly decreased while the radial distance (i.e., radial distance from the point electrode centerline) increases. The evaporation rate is inversely proportional to the radial distance. A novel empirical model based on the dependence relation between the evaporation rate, U/d ratio and radial distance was developed. The model and the experimental results agree well.

Electrode Configuration and Polarity Effects on Water Evaporation Enhancement by Electric Field

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
De-Jiang Zheng ◽  
Hong-Jiang Liu ◽  
Yong-Qiang Cheng ◽  
Li-Te Li
Keyword(s):  
Electric Field ◽  
Evaporation Rate ◽  
Electrode Configuration ◽  
Water Evaporation ◽  
Plane Electrode ◽  
Point Electrode ◽  
Water Container ◽  
Electrode Lead ◽  
Ac Field ◽  
Polarity Effects

Applying an electric field to some water solutions or food materials has been shown experimentally to increase the drying rate. In this work, an electric field was applied cross the interface of water via electrodes located upright above the water and under the water container. The polarity and the strength of the electric field and the shape of the electrodes were altered to investigate their effect on the water evaporation rate. The results show that the water evaporation rate in AC field is higher than that in DC field, indicate that the AC field have more effect in water evaporation and heat transfer than DC field. With respect to the effect of electrode configuration, the evaporation rate in the point-to-plane electrode configuration is higher than that in parallel plate, wire-plane, and tube-plane electrode configurations. The point electrode with conical end has more effect on the enhancement of water evaporation rate than that with hemispherical end and flat end. Larger the curvature of stressed electrode lead to higher water evaporation rate. However, the diameter of the rod has little effect on the evaporation rate. Both grid and plate can be used as the grounded electrode where the water samples placed, the mesh number of grid has little effect on the water evaporation rate.

STUDYING THE PROCESS OF WATER EVAPORATION WITH OF CASTOR OIL IN ELECTRIC FIELD OF MULTI-ELECTRODE SYSTEMS

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
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Keyword(s):  
Electric Field ◽  
Castor Oil ◽  
Water Evaporation ◽  
Electrode Systems

scholarly journals Highly efficient evaporative cooling by all-day water evaporation using hierarchically porous biomass

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jihun Choi ◽  
Hansol Lee ◽  
Bokyeong Sohn ◽  
Minjae Song ◽  
Sangmin Jeon
Keyword(s):  
Porous Structure ◽  
Fiber Length ◽  
Evaporation Rate ◽  
Water Evaporation ◽  
Thickness Direction ◽  
Hierarchically Porous ◽  
Hierarchically Porous Structure ◽  
Length Direction ◽  
Luffa Sponge ◽  
Fiber Thickness

AbstractWe developed a 3D solar steam generator with the highest evaporation rate reported so far using a carbonized luffa sponge (CLS). The luffa sponge consisted of entangled fibers with a hierarchically porous structure; macropores between fibers, micro-sized pores in the fiber-thickness direction, and microchannels in the fiber-length direction. This structure remained after carbonization and played an important role in water transport. When the CLS was placed in the water, the microchannels in the fiber-length direction transported water to the top surface of the CLS by capillary action, and the micro-sized pores in the fiber-thickness direction delivered water to the entire fiber surface. The water evaporation rate under 1-sun illumination was 3.7 kg/m2/h, which increased to 14.5 kg/m2/h under 2 m/s wind that corresponded to the highest evaporation rate ever reported under the same condition. The high evaporation performance of the CLS was attributed to its hierarchically porous structure. In addition, it was found that the air temperature dropped by 3.6 °C when the wind passed through the CLS because of the absorption of the latent heat of vaporization. The heat absorbed by the CLS during water evaporation was calculated to be 9.7 kW/m2 under 1-sun illumination and 2 m/s wind, which was 10 times higher than the solar energy irradiated on the same area (1 kW/m2).

scholarly journals Experimental Measurements of the Water Evaporation Rate of a Physical Model

2017 ◽  
Vol 25 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Róbert Turza ◽  
Belo B. Füri
Keyword(s):  
Energy Demand ◽  
Evaporation Rate ◽  
High Water ◽  
Hvac Systems ◽  
Swimming Pool ◽  
Water Evaporation ◽  
Specific Enthalpy ◽  
High Water Content ◽  
Indoor Environments ◽  
Indoor Swimming Pool

Abstract As the number of indoor swimming pools and wellness centers are currently growing, it is necessary to concentrate on the parameters of indoor environments. These parameters are necessary for the design of the HVAC systems that operate these premises. In indoor swimming-pool facilities, the energy demand is large due to ventilation losses from exhaust air. Since water evaporates from a pool’s surface, exhaust air has a high water content and specific enthalpy. In this paper the results of the water evaporation rate measured from swimming pool surfaces at higher thermal water temperatures are described.

The structure of the impulse corona in a rod/plane gap I. The positive corona

1970 ◽  
Vol 315 (1520) ◽  
pp. 1-25 ◽  
Keyword(s):  
Spatial Distribution ◽  
Electric Field ◽  
Space Charge ◽  
Negative Ions ◽  
Corona Discharges ◽  
Theoretical Derivation ◽  
Plane Electrode ◽  
Positive Space Charge ◽  
Positive Ion ◽  
Positive Space

The dissipation of space charge following the growth of impulse corona discharges in positive rod/earthed plane gaps has been measured with an electrostatic fluxmeter. A method is described to determine the spatial distribution and magnitude of the space charge together with the associated electric field. Initial positive ion densities of up to 100 μC m -3 have been found. The total positive space charge deposited in a 40 cm gap at 160 kV is 500 nC. Electrons emitted from the plane electrode as a result of corona channels crossing the gap are shown to be trapped in the discharge space as negative ions. The recovery of the gap over several seconds is largely due to ionic drift to the electrodes. A theoretical derivation of the rate of deionization agrees with observed values.

scholarly journals Detection of oscillatory solutions in a vacuum diode with total electron reflection

2021 ◽  
Vol 2103 (1) ◽  
pp. 012205
Author(s):  
V I Kuznetsov ◽  
IK Morozov
Keyword(s):  
Electron Beam ◽  
Electric Field ◽  
Vacuum Diode ◽  
Boundary Line ◽  
Electrode Gap ◽  
Oscillatory Solutions ◽  
Total Electron ◽  
Electron Reflection ◽  
Instability Development ◽  
Non Linear

Abstract Stability features of steady-state solutions for a vacuum diode with complete deceleration of electron beam is studied. A boundary line on the (inter-electrode gap, external voltage)-plane separating stable solutions from unstable ones is built up. An instability development is shown to end in a state with non-linear oscillations of the electric field but with no virtual cathode in a plasma. Existence of non-linear oscillations of the electric field in a vacuum diode with total reflection of an electron beam points out that such a diode can be a basis to create microwave generator.

scholarly journals Calculation of Water Evaporative Cooling Systems in Animal Husbandry

2020 ◽  
pp. 35-38
Author(s):  
N.N. Novikov ◽  
Keyword(s):  
Air Conditioning ◽  
Evaporation Rate ◽  
Evaporative Cooling ◽  
Animal Husbandry ◽  
Water Evaporation ◽  
Cooling Systems ◽  
Temperature And Humidity ◽  
Hot Weather ◽  
Livestock Building ◽  
Air Exchange

A method for calculating the parameters of the microclimate in a livestock building using water-evaporative air conditioning is described. It makes it possible to choose a rational temperature and humidity conditions for a room in hot weather, calculate the required air exchange, water evaporation rate and select the appropriate equipment.

scholarly journals Influence of a Point-to-Plane DC Negative Corona Discharge on Gel Surfaces

10.14311/1033 ◽  
2008 ◽  
Vol 48 (4) ◽  
Author(s):  
Y. Klenko ◽  
V. Scholtz
Keyword(s):  
Experimental Investigation ◽  
Surface Modification ◽  
Electric Field ◽  
Corona Discharge ◽  
Biomedical Applications ◽  
Single Point ◽  
Polymer Surfaces ◽  
Negative Corona ◽  
Negative Corona Discharge ◽  
Time Periods

Point-to-plane corona discharge is widely used for modifying polymer surfaces for biomedical applications and for sterilization and decontamination. This paper focuses on an experimental investigation of the influence of the single-point and multi-point corona discharge electric field on gel surface. Three types of gelatinous agar were used as the gel medium: blood agar, nutrient agar and Endo agar. The gel surface modification was studied for various time periods and discharge currents. 

INVESTIGATION OF SINGLE-POINT DRESSING OVERLAP RATIO AND DIAMOND-ROLL DRESSING INTERFERENCE ANGLE ON SURFACE ROUGHNESS IN GRINDING

2010 ◽  
Vol 34 (2) ◽  
pp. 295-308 ◽  
Author(s):  
Akram Saad ◽  
Robert Bauer ◽  
Andrew Warkentin
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Empirical Model ◽  
Material Removal ◽  
Removal Rate ◽  
Single Point ◽  
Experimental Conditions ◽  
Workpiece Surface ◽  
Different Depths ◽  
Overlap Ratio

This paper investigates the effect of both single-point and diamond-roll dressing techniques on the workpiece surface roughness in grinding. Two empirical surface roughness models are studied – one that incorporates single-point dressing parameters, and another that incorporates diamond-roll dressing parameters. For the experimental conditions used in this research, the corresponding empirical model coefficients are found to have a linear relationship with the inverse of the overlap ratio for single-point dressing and the interference angle for diamond-roll dressing. The resulting workpiece surface roughness models are then experimentally validated for different depths of cut, workpiece speeds and dressing conditions. In addition, the models are used to derive a relationship between overlap ratio for single-point dressing, and interference angle for diamond-roll dressing such that both dressing techniques produce a similar surface finish for a given material removal rate.

scholarly journals Influence of Magnetic Field on Evaporation Rate and Surface Tension of Water

2018 ◽  
Vol 2 (4) ◽  
pp. 68 ◽  
Author(s):  
Emil Chibowski ◽  
Aleksandra Szcześ ◽  
Lucyna Hołysz
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Evaporation Rate ◽  
Water Evaporation ◽  
Water Molecules ◽  
Surface Tension Data ◽  
Ring Magnet ◽  
The Magnetic Field

Using neodymium ring magnets (0.5–0.65 T), the experiments on the magnetic field (MF) effects on water evaporation rate and surface tension were performed at room temperature (22–24 °C). In accordance with the literature data, the enhanced evaporation rates were observed in the experiments conducted in a period of several days or weeks. However, the evaporated amounts of water (up to 440 mg over 150 min) in particular experiments differed. The evaporated amounts depended partially on which pole of the ring magnet was directed up. The relatively strong MF (0.65 T) caused a slight decrease in surface tension (−2.11 mN/m) which lasted longer than 60 min and the memory effect vanished slowly. The surface tension data reduced by the MF action are reported in the literature, although contrary results can be also found. The observed effects can be explained based on literature data of molecular simulations and the suggestion that MF affects the hydrogen bonds of intra- and inter-clusters of water molecules, possibly even causing breakage some of them. The Lorentz force influence is also considered. These mechanisms are discussed in the paper.

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