Three-Dimensional Electrohydrodynamic Enhanced Water Evaporation Using Needle-Arrayed Electrodes

Three-dimensional water evaporation is proposed based on highly vertically ordered pillar array of graphene-assembled framework (HOPGF). A high evaporation rate of 2.10 kg m−2 h−1 is achieved (1 sun). This efficient SSG system has been applied to wastewater purification, solar water heater and housing self-supply water system.

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Research on Combustion Characteristics of Cooking Oil Tar in Pipe by TG-FTIR Analysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.45 ◽

2011 ◽

Vol 236-238 ◽

pp. 45-48

Author(s):

Zheng Wen Xie ◽

Qu Fang

Keyword(s):

Combustion Process ◽

Three Dimensional ◽

Ambient Air ◽

Experimental Results ◽

Water Evaporation ◽

Pyrolysis Characteristics ◽

Second Stage ◽

Cooking Oil ◽

Third Stage ◽

Last Stage

The pyrolysis characteristics of the cooking oil tar in an ambient air were investigated using a thermogravimetric apparatus with infrared-spectrum analyzer. Experimental results showed that the combustion process of cooking oil tar can be divided into five stages. The first step of mass loss is due to water evaporation. The second stage is the volatilization and combustion of the low boiling point compound，the third stage is the combustion of instauration hydrocarbon，the fourth stage is the combustion of ester and the last stage is the combustion of saturation hydrocarbon. A simple kinetic description, named in this work as ‘First Order Reaction and Three-dimensional Diffusion Separate-stage Model (O1+D3)’ model, was developed based on the experimental results and integral analysis method.

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Computational Models for Predicting Cooling Tower Fill Performance in Cross-Counterflow Configuration

2010 14th International Heat Transfer Conference, Volume 4 ◽

10.1115/ihtc14-22791 ◽

2010 ◽

Cited By ~ 2

Author(s):

Hanno C. R. Reuter ◽

Detlev G. Kro¨ger

Keyword(s):

Computational Models ◽

Cooling Tower ◽

Air Flow ◽

Three Dimensional ◽

Cooling Water ◽

Transfer Characteristic ◽

Linear Interpolation ◽

Water Evaporation ◽

Cooling Towers ◽

Flow Angle

In cooling towers packed with trickle or splash fills, which have almost isotropic or anisotropic flow resistance, the air flow through the fill is oblique or in cross-counterflow to the water flow, particularly at the cooling tower inlet when the fill loss coefficient is small or when the fill hangs down into the air inlet region. This results that the fill Merkel number or transfer characteristic for cross-counter flow is between that of purely counter- and crossflow fills. When using CFD to model natural draught wet-cooling tower performance for isotropic fill resistance, two- or three-dimensional models are therefore required to determine fill performance. In this paper, the governing fundamental partial differential equations are derived in cylindrical and Cartesian co-ordinates to determine the cooling water temperature, water evaporation rate, air temperature and air humidity ratio in two-dimensional cross-counterflow fills for both saturated and supersaturated air. To solve these equations, a relation is proposed to determine Merkel numbers for oblique air flows by linear interpolation and extrapolation of purely cross- and counterflow Merkel numbers in terms of the air flow angle. This model is compared to analytical Merkel numbers obtained for different air flow angles using a single drop trajectory model. A linear upwind computational model and an Eulerian FLUENT® model are developed to evaluate fill performance characteristics from test data and to model fill performance in cooling towers respectively. The results of these two models are compared and verified with a FLUENT® Euler-Lagrange model.

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Three-dimensional water evaporator based on carbonized silkworm cocoon for highly effective solar-driven water evaporation and wastewater purification

Materials Letters ◽

10.1016/j.matlet.2022.131661 ◽

2022 ◽

pp. 131661

Author(s):

Lu Jia ◽

Min Feng ◽

Feng Zhang ◽

Huiming Lin ◽

Wei Guo ◽

...

Keyword(s):

Three Dimensional ◽

Water Evaporation ◽

Wastewater Purification ◽

Highly Effective ◽

Silkworm Cocoon

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Numerical simulation of methane spreading in porous media after leaking from an underground pipe

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-01-2020-0007 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Ji Wang ◽

Yuting Yan ◽

Junming Li

Keyword(s):

Heat Transfer ◽

Porous Media ◽

Numerical Model ◽

Natural Gas ◽

Three Dimensional ◽

Ground Surface ◽

Air Transportation ◽

Water Evaporation ◽

Content Type ◽

Gas Leak

Purpose Natural gas leak from underground pipelines could lead to serious damage and global warming, whose spreading in soil should be systematically investigated. This paper aims to propose a three-dimensional numerical model to analyze the methane–air transportation in soil. The results could help understand the diffusion process of natural gas in soil, which is essential for locating leak source and reducing damage after leak accident. Design/methodology/approach A numerical model using finite element method is proposed to simulate the methane spreading process in porous media after leaking from an underground pipe. Physical models, including fluids transportation in porous media, water evaporation and heat transfer, are taken into account. The numerical results are compared with experimental data to validate the reliability of the simulation model. The effects of methane leaking direction, non-uniform soil porosity, leaking pressure and convective mass transfer coefficient on ground surface are analyzed. Findings The methane mole fraction distribution in soil is significantly affected by the leaking direction. Horizontally and vertically non-uniform soil porosity has a stronger effect. Increasing leaking pressure causes increasing methane mole flux and flow rate on the ground surface. Originality/value Most existing gas diffusion models in porous media are for one- or two-dimensional simulation, which is not enough for predicting three-dimensional diffusion process after natural gas leak in soil. The heat transfer between gas and soil was also neglected by most researchers, which is very important for predicting the gas-spreading process affected by the soil moisture variation because of water evaporation. In this paper, a three-dimensional numerical model is proposed to further analyze the methane–air transportation in soil using finite element method, with the presence of water evaporation and heat transfer in soil.

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Computational Models for Predicting Cooling Tower Fill Performance in Cross-Counterflow Configuration

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4006028 ◽

2012 ◽

Vol 4 (2) ◽

Cited By ~ 3

Author(s):

H. C. R. Reuter ◽

D. G. Kröger

Keyword(s):

Computational Models ◽

Cooling Tower ◽

Air Flow ◽

Three Dimensional ◽

Cooling Water ◽

Transfer Characteristic ◽

Linear Interpolation ◽

Water Evaporation ◽

Cooling Towers ◽

Flow Angle

In cooling towers packed with trickle or splash fills, which have anisotropic flow resistance, the air flow through the fill is oblique or in cross-counterflow to the water flow, particularly at the cooling tower inlet when the fill loss coefficient is small or when the fill hangs down into the air inlet region. This results in that the fill Merkel number or transfer characteristic for cross-counter flow is between that of purely counter- and crossflow fills. When using CFD to model natural draught wet-cooling tower performance for isotropic fill resistance, two- or three-dimensional models are therefore required to determine fill performance. In this paper, the governing fundamental partial differential equations are derived in cylindrical and Cartesian coordinates to determine the cooling water temperature, water evaporation rate, air temperature, and air humidity ratio in two-dimensional cross-counterflow fills for both saturated and supersaturated air. To solve these equations, a relation is proposed to determine Merkel numbers for oblique air flows by linear interpolation and extrapolation of purely cross- and counterflow Merkel numbers in terms of the air flow angle. This model is compared to analytical Merkel numbers obtained for different air flow angles using a single drop trajectory model. A linear upwind computational model and an Eulerian FLUENT® model are developed to evaluate fill performance characteristics from test data and to model fill performance in cooling towers, respectively. The results of these two models are compared and verified with a FLUENT Euler–Lagrange model, showing minor deviations.

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Measuring evaporation distribution of mud brick and rammed earth

Structural Survey ◽

10.1108/ss-06-2013-0025 ◽

2014 ◽

Vol 32 (1) ◽

pp. 32-48 ◽

Cited By ~ 2

Author(s):

Enrico Fodde ◽

Kunio Watanabe ◽

Yukiyasu Fujii

Keyword(s):

Structural Damage ◽

Three Dimensional ◽

Eighth Century ◽

Protective Measure ◽

Water Evaporation ◽

Surface Erosion ◽

Salt Weathering ◽

Content Type ◽

Central Asian ◽

Repair Materials

Purpose – Salt weathering is one of the most common agents of decay of Central Asian earthen sites and is in function of water evaporation from the wall surface. Soon after excavation the earthen walls and the stupa of the Buddhist temple of Ajina Tepa (seventh-eighth century AD) started to deteriorate due lack of protection and surface erosion. The most important issue in the planning of conservation work was to understand such mechanisms and to decrease the effect of salt weathering on structural damage. The purpose of this paper is to discuss these issues. Design/methodology/approach – Evaporation distribution and salts types were studied on selected walls. In addition, three-dimensional recording of the walls and the stupa was undertaken with digital photogrammetric methods. Findings – It was clearly found that the intensity of salt weathering in the site is high and some salts such as halite (sodium chloride) are thought to originate from groundwater. On the basis of the results obtained, thick shelter coating with mud brick and mud render was designed and constructed as protective measure for the earthen walls. Practical implications – Those walls that were most affected by salts weathering and erosion at the base (coving) became structurally less sound and eventually collapsed if not conserved. Originality/value – The work is the first attempt in the design of a methodology for the selection of earthen repair materials and methods.

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The orbit of Pluto over a long interval of time

Symposium - International Astronomical Union ◽

10.1017/s0074180900105509 ◽

1966 ◽

Vol 25 ◽

pp. 227-229 ◽

Cited By ~ 1

Author(s):

D. Brouwer

Keyword(s):

Periodic Orbit ◽

Numerical Integration ◽

Restricted Problem ◽

Three Dimensional ◽

The Third ◽

Circular Restricted Problem ◽

Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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