scholarly journals Symmetric-in-Plane Compression of Polyamide Pantographic Fabrics—Modelling, Experiments and Numerical Exploration

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 693 ◽  
Author(s):  
Chuong Anthony Tran ◽  
Maciej Gołaszewski ◽  
Emilio Barchiesi
Keyword(s):  
Experimental Data ◽  
Present Article ◽  
Lattice Structure ◽  
Experimental Results ◽  
Fiber Density ◽  
Numerical Exploration ◽  
Peculiar Behaviour ◽  
Plane Compression ◽  
Pantographic Fabrics

Symmetric in-plane compression of a pantographic lattice structure is modelled and simulated, and the results are compared to previously available experimental data. Said experimental results had shown a peculiar behaviour: depending on the fiber density, the deformed shape could present either one or two swellings under compression. The present article is a preliminary modelling attempt aiming at capturing that behaviour numerically.

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

Validating Numerical CFD Simulations With Experimental Data for Turbulence Phenomena in Axial Flow Gas Turbine Diffusers

2009 ◽  
Author(s):  
Farrokh Zarifi-Rad ◽  
Hamid Vajihollahi ◽  
James O’Brien
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Axial Flow ◽  
Experimental Results ◽  
Scale Model ◽  
Data Set ◽  
Pressure Profiles ◽  
Scale Models ◽  
Inlet Conditions

Scale models give engineers an excellent understanding of the aerodynamic behavior behind their design; nevertheless, scale models are time consuming and expensive. Therefore computer simulations such as Computational Fluid Dynamics (CFD) are an excellent alternative to scale models. One must ask the question, how close are the CFD results to the actual fluid behavior of the scale model? In order to answer this question the engineering team investigated the performance of a large industrial Gas Turbine (GT) exhaust diffuser scale model with performance predicted by commercially available CFD software. The experimental results were obtained from a 1:12 scale model of a GT exhaust diffuser with a fixed row of blades to simulate the swirl generated by the last row of turbine blades five blade configurations. This work is to validate the effect of the turbulent inlet conditions on an axial diffuser, both on the experimental front and on the numerical analysis approach. The object of this work is to bring forward a better understanding of velocity and static pressure profiles along the gas turbine diffusers and to provide an accurate experimental data set to validate the CFD prediction. For the CFD aspect, ANSYS CFX software was chosen as the solver. Two different types of mesh (hexagonal and tetrahedral) will be compared to the experimental results. It is understood that hexagonal (HEX) meshes are more time consuming and more computationally demanding, they are less prone to mesh sensitivity and have the tendancy to converge at a faster rate than the tetrahedral (TET) mesh. It was found that the HEX mesh was able to generate more consistent results and had less error than TET mesh.

Heats of mixing of binary mixtures of pyridine base with n-alkane

1988 ◽  
Vol 66 (7) ◽  
pp. 1625-1627 ◽  
Author(s):  
Teresa Kasprzycka-Guttman ◽  
Juan H. Vera
Keyword(s):  
Experimental Data ◽  
Binary Mixtures ◽  
Experimental Results ◽  
Pyridine Base ◽  
Heats Of Mixing

Heats of mixing of 2,4-lutidine and 2,4,6-collidine with n-alkanes were measured at 293.15 K using an isothermal dilution calorimeter. Experimental results were fitted with a Redlich–Kister polynomial. Experimental data and coefficients for the Redlich–Kister polynomials are reported.

A Statistical Adaptable Distribution Function Model for Low Probabilities of Failure

1993 ◽  
Author(s):  
Suryaji R. Bhonsle ◽  
Paul Thompson
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Experimental Results ◽  
Function Model ◽  
Log Normal ◽  
Function Models

Abstract Weibull, log normal, and some other Distribution function models (D.F.M.) have a tendency to deviate from experimental results. This deviation, either exceedingly conservative or nonconservative, is amplified at low probabilities of failure. To remedy such problems a new D.F.M. is derived. It is then used to predict low probabilities of failure. The predictions are consistent with experimental data and are not too conservative or too nonconservative.

Lherzolite - carbonatite melt interaction in the presence of additive CO2 and H2O: Experimental data at 5.5 GPa and 1200-1450°C

2021 ◽  
Author(s):  
Aleksei Kruk ◽  
Alexander Sokol
Keyword(s):  
Experimental Data ◽  
Lithospheric Mantle ◽  
Fluid Phase ◽  
Experimental Results ◽  
Silicate Melt ◽  
Silicate Melts ◽  
Garnet Lherzolite ◽  
Russian Science ◽  
Continental Lithospheric Mantle

<p>We study the reaction of garnet lherzolite with carbonatitic melt rich in molecular CO<sub>2</sub> and/or H<sub>2</sub>O in experiments at 5.5 GPa and 1200-1450°C. The experimental results show that carbonation of olivine with formation of orthopyroxene and magnesite can buffer the CO<sub>2</sub> contents in the melt, which impedes immediate separation of CO<sub>2</sub> fluid from melt equilibrated with the peridotite source. The solubility of molecular CO<sub>2</sub> in melt decreases from 20-25 wt.% at 4.5-6.8 wt.% SiO<sub>2</sub> typical of carbonatite to 7-12 wt.% in more silicic kimberlite-like melts with 26-32 wt.% SiO<sub>2</sub>. Interaction of garnet lherzolite with carbonatitic melt (2:1) in the presence of 2-3 wt.% H<sub>2</sub>O and 9-13 wt.% molecular CO<sub>2</sub> at 1200-1450°С yields low SiO<sub>2</sub> (<10 wt.%) alkali‐carbonatite melts, which shows multiphase saturation with magnesite-bearing garnet harzburgite. Thus, carbonatitic melts rich in volatiles can originate in a harzburgite source at moderate temperatures common to continental lithospheric mantle (CLM).</p><p>Having separated from the source, carbonatitic magma enriched in molecular CO<sub>2</sub> and H<sub>2</sub>O can rapidly acquire a kimberlitic composition with >25 wt.% SiO<sub>2 </sub>by dissolution and carbonation of entrapped peridotite. Furthermore, interaction of garnet lherzolite with carbonatitic melt rich in K, CO<sub>2</sub>, and H<sub>2</sub>O at 1350°С produces immiscible kimberlite-like carbonate-silicate and K-rich silicate melts. Quenched silicate melt develops lamelli of foam-like vesicular glass. Differentiation of immiscible melts early during ascent may equalize the compositions of kimberlite magmas generated in different CLM sources. The fluid phase can release explosively from ascending magma at lower pressures as a result of SiO<sub>2</sub> increase which reduces the solubility of CO<sub>2</sub> due to decarbonation reaction of magnesite and orthopyroxene.</p><p>The research was performed by a grant of the Russian Science Foundation (19-77-10023).</p>

Experimental and Theoretical Investigation of Performance of a Solar Chimney Model, Part I: Experimental Investigation

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Essaied M Shuia ◽  
Bashir H Arebi ◽  
Ibrahim A abuashe
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Solar Radiation ◽  
Air Temperature ◽  
Solar Collector ◽  
Experimental Results ◽  
Internal Diameter ◽  
Solar Chimney ◽  
Air Velocity ◽  
Collector Temperature

This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.

A Percolation Equation for Modeling Experimental Results for Continuum Percolation Systems

2001 ◽  
Vol 699 ◽  
Author(s):  
D.S. McLachlan ◽  
C. Chiteme ◽  
W.D. Heiss ◽  
Junjie Wu
Keyword(s):  
Experimental Data ◽  
Ac Conductivity ◽  
Volume Fraction ◽  
Power Laws ◽  
Second Order ◽  
Experimental Results ◽  
Analytical Equation ◽  
Scaling Properties ◽  
First Order ◽  
Dc And Ac Conductivity

AbstractThe standard percolation equations or power laws, for dc and ac conductivity (dielectric constant) are based on scaling ansatz, and predict the behaviour of the first and second order terms, above and below the percolation or critical volume fraction (øc), and in the crossoverregion. Recent experimental results on ac conductivity are presented, which show that these equations, with the exception of real σm above øc and the first order terms in the crossover region, are only valid in the limit σi/σc = 0, where for an ideal dielectric σi=ωε0εr.A single analytical equation, which has the same parameters as the standard percolation equations, and which, for ac conductivity, reduces to the standard percolation power laws in the limit σi(ωε0εr)/σc = 0 for all but one case, is presented. The exception is the expression for real σm below øc, where the standard power law is always incorrect. The equation is then shown to quantitatively fit both first and second order dc and ac experimental data over the entire frequency and composition range. This phenomenological equation is also continuous, has the scaling properties required at a second order metal-insulator and fits scaled first order dc and ac experimental data. Unfortunately, the s and t exponents that are necessary to fit the data to the above analytical equation are usually not the simple dimensionally determined universal ones and depend on a number of factors.

Characteristics of Hydraulic Shock Waves in an Inclined Chute Contraction - Experiments

2009 ◽  
Vol 25 (1) ◽  
pp. 129-136 ◽  
Author(s):  
C.-D. Jan ◽  
C.-J. Chang ◽  
J.-S. Lai ◽  
W.-D. Guo
Keyword(s):  
Experimental Data ◽  
Shock Waves ◽  
Froude Number ◽  
Inclination Angle ◽  
Laboratory Experiments ◽  
Deflection Angle ◽  
Experimental Results ◽  
Regression Analyses ◽  
Hydraulic Shock ◽  
Empirical Relations

AbstractThis paper presents the experimental results of the characteristics of hydraulic shock waves in an inclined chute contraction with consideration of the effects of sidewall deflection angle φ, bottom inclination angle θ and approach Froude number Fr0. Seventeen runs of laboratory experiments were conducted in the range of 27.45° ≤φ ≤ 40.17°, 6.22° ≤ θ ≤ 25.38° and 1.04 ≤ Fr0 ≤ 3.51. Based on the experimental data, three empirical dimensionless relations for the shock angle, maximum shockwave height, and corresponding position of maximum shockwave were obtained by regression analyses, respectively. These empirical relations would be useful for hydraulic engineers in designing chute contraction structures.

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