scholarly journals Dehumidification Performance of LiCl in Falling Film Type Liquid Desiccant Dehumidifier

In the present study, CFD analysis of falling film type liquid desiccant dehumidifier is carried out to predict its performance In these simulations it is studied how the flow pattern of liquid desiccant effects the interaction between the moist air and the liquid desiccant.Two dimensional model was simulated by using the software ANSYS (FLUENT). The volume of fluid (VOF) was selected as the multiphase method for the simulation process. The water vapor/humidity content in the air is given by using species transport model and the variation of amount of water hold by the air is simulated. The liquid desiccant considered for study is LiCl with 30% concentration and the mass fraction of water vapor used in air is varied from 0.01 to 0.02. The properties of LiCl at 30% concentration were calculated and inlet parameters of air and desiccant are fed to the software as input. The model was subjected to different inlet mass fractions and determined the dehumidification effectiveness.

2021 ◽  
Vol 20 (2) ◽  
pp. 101-106
Author(s):  
Ahmed Benali ◽  
Bellaouar Abderrahmane ◽  
Lalmi Djemoui ◽  
Hadef Redjem

This work is devoted to the comparative study for the formation and dissociation of nitrogen oxides by the numerical simulation of turbulent combustion without premix in a combustion chamber having a cylindrical shape with two coaxial jets, two flames using the ANSYS fluent software16.0. The study focuses on the influence of the type of fuel on the composition of discharges in content with NOx, that is to say two cases are treated and compared. Turbulence is modeled by the k-ε model and the chemical aspect of combustion is treated by the PDF model for each flame. The calculation results relate to the characteristics of dynamic fields, temperature, the mass fractions of different species involved in the combustion process and the NOx prediction. The effect of the swirl is also tested in this study with a CFD prediction of non premixed swirling g flame. These results are compared with measurements and confrontations is satisfactory.


2016 ◽  
Vol 23 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Yimo Luo ◽  
Yi Chen ◽  
Dan Zhong ◽  
Yuanhao Wang ◽  
Hongxing Yang

Author(s):  
Alexander Führing ◽  
Subha Kumpaty ◽  
Chris Stack

In external and internal fluid flow analysis using numerical methods, most attention is paid to the properties of the flow assuming absolute rigidity of the solid bodies involved. However, this is often not the case for water flow or other fluids with high density. The pressure forces cause the geometry to deform which in turn changes the flow properties around it. Thus, a one-way and two-way Fluid-Structure Interaction (FSI) coupling is proposed and compared to a CFD analysis of a windsurfing fin in order to quantify the differences in performance data as well as the properties of the flow. This leads to information about the necessity of the use of FSI in comparison to regular CFD analysis and gives indication of the value of the enhanced results of the deformable analysis applied to water flow around an elastically deformable hydrofoil under different angles of attack. The performance data and flow property evaluation is done in ANSYS Fluent using the k-ω SST and k-ε model with a y+ of 1 and 35 respectively in order to be able to compare the behavior of both turbulence models. It is found that the overall lift coefficient in general is lower and that the flow is less turbulent because of softer transition due to the deformed geometry reducing drag forces. It is also found that the deformation of the tip of the hydrofoil leads to vertical lift forces. For the FSI analysis, one-way and two-way coupling were incorporated leading to the ability to compare results. It has been found that one-way coupling is sufficient as long as there is no stall present at any time.


2001 ◽  
Vol 67 (660) ◽  
pp. 2105-2112 ◽  
Author(s):  
Hideo INABA ◽  
Takahisa KIDA ◽  
Akihiko HORIBE ◽  
Kiyohiro KAMEDA ◽  
Tamio OKAMOTO ◽  
...  

Author(s):  
C. F. Castro-Bolinaga ◽  
E. R. Zavaleta ◽  
P. Diplas

Abstract. This paper presents the preliminary results of a coupled modelling effort to study the fate of tailings (radioactive waste-by product) downstream of the Coles Hill uranium deposit located in Virginia, USA. The implementation of the overall modelling process includes a one-dimensional hydraulic model to qualitatively characterize the sediment transport process under severe flooding conditions downstream of the potential mining site, a two-dimensional ANSYS Fluent model to simulate the release of tailings from a containment cell located partially above the local ground surface into the nearby streams, and a one-dimensional finite-volume sediment transport model to examine the propagation of a tailings sediment pulse in the river network located downstream. The findings of this investigation aim to assist in estimating the potential impacts that tailings would have if they were transported into rivers and reservoirs located downstream of the Coles Hill deposit that serve as municipal drinking water supplies.


2017 ◽  
Vol 124 ◽  
pp. 91-102 ◽  
Author(s):  
J. Emhofer ◽  
B. Beladi ◽  
P. Dudzinski ◽  
T. Fleckl ◽  
H.C. Kuhlmann

2021 ◽  
Author(s):  
Franz-Josef Lübken ◽  
Gerd Baumgarten

<p>Noctilucent clouds are often cited as potential indicators of climate change in the middle<br>atmosphere. They owe their existence to the very cold summer mesopause region (~130K) at mid<br>and high latitudes. We analyze trends derived from the Leibniz-Institute Middle Atmosphere<br>Model (LIMA) and the MIMAS ice particle model (Mesospheric Ice Microphysics And tranSport model)<br>for the years 1871-2008 and for middle, high and arctic latitudes, respectively.<br>Model runs with and without an increase of carbon dioxide and water vapor (from methane oxidation)<br>concentration are performed. Trends are most prominent after ~1960 when the increase of both<br>carbon dioxide and water vapor accelerates. Negative trends of (geometric) NLC altitudes are primarily<br>due to cooling below NLC altitudes caused by carbon dioxide increase. Increases of ice particle<br>radii and NLC brightness with time are mainly caused by an enhancement of water vapor.<br>Several ice layer and background parameter trends are similar at high and arctic latitudes but are<br>substantially different at middle latitudes. This concerns, for example, occurrence rates, ice water<br>content (IWC), and number of ice particles in a column. Considering the time period after 1960,<br>geometric altitudes of NLC decrease by approximately 260m per decade, and brightness increases by<br>roughly 50% (1960-2008), independent of latitude. NLC altitudes decrease by approximately 15-20m<br>per increase of carbon dioxide by 1ppmv. The number of ice particles in a column and also at the<br>altitude of maximum backscatter is nearly constant with time. At all latitudes, yearly mean NLC<br>appear at altitudes where temperatures are close to 145+/-1K. Ice particles are present nearly<br>all the time at high and arctic latitudes, but are much less common at middle latitudes. Ice water<br>content and maximum backscatter are highly correlated, where the slope depends on latitude. This<br>allows to combine data sets from satellites and lidars. Furthermore, IWC and the concentration of<br>water vapor at the altitude of maximum backscatter are also strongly correlated. Results from<br>LIMA/MIMAS agree nicely with observations.</p>


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