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 %.

The penetration and ricochet of ogive-nosed rigid projectiles obliquely impacting metallic targets

2021 ◽  
pp. 204141962110377
Author(s):  
Yaniv Vayig ◽  
Zvi Rosenberg
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Dynamic Pressure ◽  
Oblique Impacts ◽  
Simulation Results ◽  
The Impact ◽  
Penetration Depths ◽  
Resistance To Penetration ◽  
Good Agreement

A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.

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 Use of growth regulators and experimental LED phytoirradiator in clonal micropropagation of garden strawberry (Fragaria × ananassa, Duchesne ex Weston)

2019 ◽  
Vol 20 (4) ◽  
pp. 324-333 ◽  
Author(s):  
M. G. Markova ◽  
E. N. Somova
Keyword(s):  
Experimental Data ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Fragaria Ananassa ◽  
Clonal Micropropagation ◽  
Fluorescent Lamps ◽  
Combined Use ◽  
The Impact ◽  
Reproduction Factor

The article provides experimental data of 2017-2018 study on the effect of growth regulators and LED phytoirradiator on the proliferation and rooting of promising garden strawberry (Fragaria ananassa) varieties in vitro. Micro-shoots of Korona and Brighton strawberry varieties were taken as the object of the research. Strawberry micro-shoots were cultivated under fluorescent lamps in the control variant. A programmable combined blinking LED phytoirradiator was under study. The combined effect of cytokinin and gibberellic acid by adding them to the Murashige and Skoog nutrient medium, as well as the impact of Siliplant and EcoFus growth regulators on strawberry micropropagation has been studied. It was established that in the cultivation of Korona variety the combined use of Siliplant and EcoFus under illumination with LED phytoirradiator provided an increase in the reproduction factor. The coefficient was 5.0 pcs./explant that was 1.7 times higher than the control (3.0 pcs/explant), the LSD05 1.4 pcs/explant. The maximum reproduction factor of remontant strawberry Brighton variety was obtained in the variant with the use of Siliplant and LED phytoirradiator and amounted to 4.9 pcs./explant (4.2 pcs./explant in the control), the LSD05 was 1.5 pcs./ explant. Regardless of the lighting, the use of RibavExtra in all variants under study increased the rooting rate of the strawberry Korona micro-shoots from 92.8 to 99.1%, the LSD05 6.1%. The use of LED phytoirradiator in comparison with the luminescent one (94.3%) provided a significant increase in the rooting rate of the strawberry Korona micro-shoots to 98.1% regardless of the growth regulators used, the LSD05 3.5%. The combined use of LED phytoirradiator and Ribav-Extra growth regulator in concentrations of 1.0 and 1.5 mg/l resulted in rooting of strawberry Korona micro-shoots up to 100%. Regardless of the growth regulator used, the use of LED phytoirradiator in comparison with the luminescent one (88.9%) provided a significant increase in the rooting rate of the strawberry Brighton micro-shoots to 97.2%, the LSD05 4.6%. The rooting rate of the remontant strawberry Brighton microshoots was 100% in the variant with the use of Ribav-Extra in the concentration of 1.0 mg /l combined with LED phytoirradiator 20 days after transplanting for rooting.

Empirical estimation of engine-integration noise for high bypass ra-tio turbofan engines

2021 ◽  
Vol 263 (2) ◽  
pp. 4511-4519
Author(s):  
Incheol Lee ◽  
Yingzhe Zhang ◽  
Dakai Lin
Keyword(s):  
Experimental Data ◽  
Pressure Side ◽  
Empirical Estimation ◽  
Low Frequencies ◽  
High Frequencies ◽  
Turbofan Engines ◽  
Proposed Model ◽  
The Impact ◽  
Bypass Ratio ◽  
Good Agreement

To investigate the impact of installation on jet noise from modern high-bypass-ratio turbofan engines, a model-scale noise experiment with a jet propulsion system and a fuselage model in scale was conducted in the anechoic wind tunnel of ONERA, CEPRA 19. Two area ratios (an area of the secondary nozzle over an area of the primary nozzle), 5 and 7, and various airframe configurations such as wing positions relative to the tip of the engine nacelle and flap angles, were considered. Based on the analysis of experimental data, an empirical model for the prediction of engine installation noise was proposed. The model comprises two components: one is the interaction be-tween the jet and the pressure side of the wing, and the other is the interaction between the jet and the flap tip. The interaction between the jet and the pressure side of the wing contributes to the noise at the low frequencies (≤ 1.5 kHz), and the interaction between the jet and the flap tip con-tributes to the noise at the high frequencies. The proposed model showed a good agreement with the experimental data.

scholarly journals Effects of hydrophobic CaO and SiO2 nanoparticles on Asphaltene Precipitation Envelope (APE): an experimental and modeling approach

2018 ◽  
Vol 73 ◽  
pp. 56 ◽  
Author(s):  
Yaser Ahmadi ◽  
Babak Aminshahidy
Keyword(s):  
Experimental Data ◽  
Saturation Pressure ◽  
Sio2 Nanoparticles ◽  
Asphaltene Precipitation ◽  
Modeling Approach ◽  
Different Temperatures ◽  
Nanoparticles Concentration ◽  
Onset Pressure ◽  
The Impact ◽  
Good Agreement

An experimental and modeling approach was developed in this research to investigate the effects of CO2, new synthesized CaO and commercial SiO2 nanoparticle concentrations on the Asphaltene Precipitation Envelope (APE). First, the effects of different temperatures and CO2 concentrations on asphaltene precipitation trends were observed. Second, the impact of CaO and SiO2 nanoparticle concentrations on asphaltene precipitation were observed in the presence of CO2 at different temperatures. Third, Advanced Redlich-Kwong-Soave (RKSA) equation of state (EOS) was considered to modify Multiflash (Infochem Co.) software from the aspect of entering physical characteristics of CaO and SiO2 nanoparticles as pseudo components. Fourth, the developed model was used for predicting the effects of CO2, CaO and SiO2 concentrations on APE in ranges that no experimental data existed. At constant CO2 concentration and temperature during natural depletion, asphaltene precipitation increased above saturation pressure, while below saturation pressure, asphaltene precipitation decreased (solution gas evolved from crude oil and made it richer). As temperature increased at constant CO2 concentration, asphaltene precipitation decreased, while it was observed that the saturation pressures increased. Although two different trends were observed in upper asphaltene onsets at different temperatures and CO2 concentrations, in wide ranges of data, as temperature increased, asphaltene upper onset pressure increased. CaO and SiO2 nanoparticles decreased asphaltene precipitations in the presence of CO2, but CaO had better applications for reducing asphaltene precipitation. The proposed Software/RKSA EOS model was in good agreement with the obtained experimental data, and it was applicable for predicting the effects of CO2, CaO and SiO2 nanoparticles concentration on APE.

Ab Initio Study of Clean and Hydrogen-Saturated Unreconstructed SiC{0001} Surfaces

2007 ◽  
Vol 556-557 ◽  
pp. 493-496 ◽  
Author(s):  
Alexander Mattausch ◽  
T. Dannecker ◽  
Oleg Pankratov
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Surface States ◽  
Correlation Effects ◽  
Ab Initio Study ◽  
Functional Theory ◽  
Hubbard U ◽  
The Impact ◽  
Good Agreement

Using density functional theory, we investigate the 6H-SiC{0001} surfaces in the unreconstructed 1 × 1 and the H-passivated configuration. The strong correlation effects of the dangling bonds at the surface are treated by spin-polarised calculations including the Hubbard-U parameter. We find that the clean surfaces are semiconducting with surface states in good agreement with experimental data. The impact of the Hubbard-U is stronger on the C-terminated face. For the H-passivated surfaces we find resonances in the valence band. The antibonding C−H state is located in the upper part of the bandgap around the ¯􀀀-point.

Analysis of perforation process into concrete/metal targets by rigid projectiles

2012 ◽  
Vol 227 (7) ◽  
pp. 1454-1468 ◽  
Author(s):  
N Khazraiyan ◽  
GH Liaghat ◽  
H Khodarahmi ◽  
N Dashtian-Gerami
Keyword(s):  
Experimental Data ◽  
Numerical Modeling ◽  
Cavity Expansion ◽  
Velocity Range ◽  
Material Models ◽  
Backing Plate ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
The Impact ◽  
Good Agreement

In this article, a semi-analytical model has been developed for perforation of a hard projectile into a single- and two-layer concrete targets. The model is based on the dynamic cavity expansion theory and the reflection of compressive waves from the end of the concrete targets. The effect of friction coefficient is also investigated in the analysis. Numerical modeling of the problem has been performed in LS-DYNA code. Holmquist–Johnson–Cook, plastic kinematic, and rigid material models have been employed for the concrete, the backing plate, and the projectile, respectively. The impact velocity range, considered in this study, is between 300 and 800 m/s. No projectile erosion is considered in this velocity range. The analytical results of the investigation for both single- and two-layer concrete targets are in a good agreement with numerical simulations and 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.

Flow over a containment dyke

1978 ◽  
Vol 87 (1) ◽  
pp. 179-192 ◽  
Author(s):  
H. P. Greenspan ◽  
R. E. Young
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Fluid Motion ◽  
Strong Shock ◽  
Safety Barrier ◽  
Large Tank ◽  
The Impact ◽  
Good Agreement

The wall of a large tank or reservoir breaks, sending fluid against a secondary containment dyke. The impact of the surging fluid against the safety barrier is studied. The results of theoretical analysis and numerical simulation (for vertical dykes) are in good agreement with experimental data concerning overflow and total spillage as well as the fluid motion after collision, including the development and formation of a strong shock. The dependence of spillage on the inclination of the dyke is also determined by experiment.

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%.

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