Research on Dropwise Condensation for Binary Mixed Vapor

2012 ◽  
Vol 190-191 ◽  
pp. 1355-1360
Author(s):  
Shen Hua Hu ◽  
Xiang Rong Ma ◽  
Fan Wu
Keyword(s):  
Experimental Data ◽  
Size Distribution ◽  
Mass Concentration ◽  
Drop Size ◽  
Pure Water ◽  
Maximum Error ◽  
Vertical Surface ◽  
Experimental Result ◽  
Vapor Velocity ◽  
Good Agreement

An experiment for Marangoni condensation of ethanol-water mixtures was carried out and the departing radius and drop size distribution on vertical surface was presented. An amended formula was obtained after considering the effect of ethanol mass concentration, vapor velocity and condensing temperature difference based on Le Fevre’s formula concerning departing radius of pure water, The calculations were in good agreement with experimental result, had a maximum error less than 23%. Owing to the significant effect on drop size contribution, vapor velocity was introduced into Rose’s formula, and the correctional result compared well with the experimental data.

scholarly journals On the Shape–Slope Relation of Drop Size Distributions in Convective Rain

2005 ◽  
Vol 44 (7) ◽  
pp. 1146-1151 ◽  
Author(s):  
Axel Seifert
Keyword(s):  
Size Distribution ◽  
Gamma Distribution ◽  
Drop Size ◽  
Empirical Relation ◽  
Size Distributions ◽  
Shape Parameters ◽  
Raindrop Size Distribution ◽  
Raindrop Size ◽  
Drop Size Distributions ◽  
Good Agreement

Abstract The relation between the slope and shape parameters of the raindrop size distribution parameterized by a gamma distribution is examined. The comparison of results of a simple rain shaft model with an empirical relation based on disdrometer measurements at the surface shows very good agreement, but a more detailed discussion reveals some difficulties—for example, deviations from the gamma shape and the overestimation of collisional breakup.

A theoretical model to study melting of metals under pressure

2015 ◽  
Vol 29 (27) ◽  
pp. 1550161 ◽  
Author(s):  
Kuldeep Kholiya ◽  
Jeewan Chandra
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Melting Temperature ◽  
Present Model ◽  
Melting Curve ◽  
Experimental Result ◽  
Thermal Equation ◽  
Simple Theoretical Model ◽  
Pressure Melting ◽  
Good Agreement

On the basis of the thermal equation-of-state a simple theoretical model is developed to study the pressure dependence of melting temperature. The model is then applied to compute the high pressure melting curve of 10 metals (Cu, Mg, Pb, Al, In, Cd, Zn, Au, Ag and Mn). It is found that the melting temperature is not linear with pressure and the slope [Formula: see text] of the melting curve decreases continuously with the increase in pressure. The results obtained with the present model are also compared with the previous theoretical and experimental data. A good agreement between theoretical and experimental result supports the validity of the present model.

Sound absorption characterization of aluminum foam made by press infiltration casting

2016 ◽  
Vol 12 (4) ◽  
pp. 737-747 ◽  
Author(s):  
J.X. Sun ◽  
C.Y. Duan ◽  
P.S. Liu
Keyword(s):  
Experimental Data ◽  
Absorption Coefficient ◽  
Sound Wave ◽  
Sound Absorption ◽  
Aluminum Foam ◽  
Peak Frequency ◽  
Experimental Result ◽  
Content Type ◽  
Improved Model ◽  
Good Agreement

Purpose The purpose of this paper is to investigate the sound absorption by modeling for the aluminum foam produced by press infiltration casting. Design/methodology/approach First use Johnson-Allard-Champoux (JAC) model to calculate the sound absorption coefficient of the present aluminum foam, and then improve it after finding its deviation from the experimental data, so as to get an improved model that could have a good agreement with the experimental result. Findings Using JAC model to calculate the sound absorption coefficient of the present aluminum foam, it is found that the model may have a good agreement with the experimental data only for the sound wave frequency below the absorption peak frequency, but a large deviation from the experimental result for the sound wave frequency above this frequency. Originality/value Improving JAC model by means of two factors, i.e., the absorption peak frequency and the specific surface area, the resultant improved model could be in good agreement with the experimental data.

Analysis on a Counter-Current Flow Hemodialyzer

2009 ◽  
Vol 4 (5) ◽  
Author(s):  
Norman W Loney
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Closed Form Solution ◽  
Maximum Error ◽  
Form Solution ◽  
Transfer Coefficients ◽  
Confluent Hypergeometric Functions ◽  
Proposed Model ◽  
Counter Current ◽  
Good Agreement

The closed form solution to the conjugated boundary value problem posed by a counter current hemodialyzer facilitates the estimation of the overall mass transfer coefficient. Comparison of the proposed model results with published experimental data shows good agreement for Urea and Creatinine clearances over a published range of blood and dialyzate flow rates. This model predicts clearances with a maximum error of less than 4% for both Urea and Creatinine when blood flow is 75% of the dialyzate flow. However, when both blood and dialyzate flows are identical the model over predicts the experimental data by 1.47% in the case of Urea and 4.75 for Creatinine flows of 300 ml/min. Although the concentration profile is an infinite series involving confluent hypergeometric functions, 2 terms of the series were sufficient (Mathematica notebook program) to produce these results. Overall mass transfer coefficients can now be deduced from the Sherwood numbers and provide possible improvement over currently used area coefficients.

Prediction of Steel Transformation Temperatures Using Thermodynamic Modeling and Design of Experiments (DOE)

2018 ◽  
Vol 941 ◽  
pp. 2284-2289
Author(s):  
Abdelhalim Loucif ◽  
Heithem Touazine ◽  
Mohammad Jahazi
Keyword(s):  
Experimental Data ◽  
Design Of Experiments ◽  
Maximum Error ◽  
Simple Approach ◽  
Alloying Element ◽  
Transformation Temperatures ◽  
Combined Use ◽  
The Impact ◽  
Liquidus Temperatures ◽  
Good Agreement

This paper presents a methodology in order to predict A1, solidus and liquidus temperatures using a relatively simple approach. The proposed approach is based on the combined use of the thermodynamic software Thermo-Calc and the composite centered design of experiments (DOE) method. Four important alloying elements (C, Ni, Mn and Cr) were considered in the DOE. The impact of each alloying element on the transformation temperatures was determined and discussed. It was found that carbon has the most important impact on solidus and liquidus whereas Ni, Mn, and Cr have a significant impact on A1. The proposed models were generated using Analysis of Variance (ANOVA) method. A good agreement between experimental and predicted results was found with a maximum error of 1.1 % for transformation temperatures. Furthermore, the proposed models were validated using a large amount of experimental data published in the literature with a maximum error equal to 7.8 %.

VAV System Operating in an Educational Building Under Tropical Conditions: Modeling and Simulation

2013 ◽  
Author(s):  
Oscar Alvarez ◽  
Marco Sanjuan ◽  
Fabian Amaya ◽  
Antonio Bula
Keyword(s):  
Experimental Data ◽  
Energy Consumption ◽  
Modeling And Simulation ◽  
Transient Process ◽  
Maximum Error ◽  
Tropical Conditions ◽  
Caribbean Area ◽  
The Caribbean ◽  
System Operating ◽  
Good Agreement

An educational building located in the Caribbean area of Colombia that uses a VAV system has been modeled and simulated in order to quantify the energy consumption. The energy values attained has been compared with the real energy consumption obtained from the data system. The results show that the error introduced are sensitive to the building mass at the beginning of the transient process, never the less, as the transient continues, the software shows good agreement with the experimental data. The maximum error at the beginning is 25% and decreases to 10%.

Evaluation of Pore Size Distribution for Controlled Permeability Formwork Liner

2014 ◽  
Vol 534 ◽  
pp. 53-62
Author(s):  
Zheng Hong Tian ◽  
Xiao Dong Wang
Keyword(s):  
Experimental Data ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Good Accuracy ◽  
Functional Material ◽  
Nonwoven Fabrics ◽  
The Matrix ◽  
Accuracy And Repeatability ◽  
Good Agreement

Controlled permeability formwork liner (CPFL) is the functional material similar to nonwoven fabrics and its filtration and drainage performance is dominated by the pore size distribution (PSD) of matrix. In this paper, suction table method, generally used to measure soil pore diameter, is improved for testing PSD of CPFL and experimental data was compared to the results from four other normal experimental methods, i.e., wet sieving method, bubble point method, mercury intrusion porosimetry (MIP) method and image analysis. The comparison indicates that PSD of CPFL obtained from suction table show good accuracy and repeatability. Furthermore, a modified mathematical model derived from Rawal model and Fature model is proved to be suitable for determinating PSD of the matrix of CPFLwith bilayer structure, and have a good agreement with the experimental data from suction table.

A Theoretical Approach to Dropwise Condensation Using Population Balance Concept

2004 ◽  
Author(s):  
S. Vemuri ◽  
K. J. Kim ◽  
B. D. Wood ◽  
T. W. Bell
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Theoretical Model ◽  
Size Distribution ◽  
Drop Size ◽  
Population Balance ◽  
Theoretical Formula ◽  
Dropwise Condensation ◽  
Sweeping Effect ◽  
Direct Condensation

A model using the population balance concept is used to derive a theoretical formula to predict the drop-size distribution of small drops which grow mainly by direct condensation. All the important resistances to heat transfer such as the heat conduction through the drop, vapor-liquid interface are considered in developing this model. By knowing the contact angle of the drop made with the condensing surface and the maximum drop radius the sweeping effect of large falling drops could be calculated which is also incorporated into the model. This is combined with the well known size distribution for large drops proposed by Le Fevre and Rose (1966) which grow mainly by coalescence and with the growth rate of single drops to compute the heat flux during the process of dropwise condensation. The data obtained from this theoretical model is compared to that of the data obtained from our experimentation. There has been a satisfactory agreement between our experimental data and the present theoretical model.

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