Smoothing of a stationary random signal in a continuous mixer

1987 ◽  
Vol 52 (7) ◽  
pp. 1730-1741
Author(s):  
Pavel Hasal ◽  
Jitka Vyhlídková ◽  
Vladimír Kudrna
Keyword(s):  
Experimental Data ◽  
Residence Time ◽  
Theoretical Concept ◽  
Random Signal ◽  
Smoothing Effect ◽  
Experimental Conditions ◽  
Stochastic Fluctuations ◽  
Wide Range ◽  
Concentration Signal ◽  
Good Agreement

The paper presents results of the first stage of experimental verification of the theoretical concept published in the two first preceding communications concerning the flow of liquid in a continuous nonideal mixer and, namely, the smoothing effect of such a mixer on a passing stationary random concentration signal. In a sufficiently wide range of experimental conditions it has been proven that stochastic fluctuations of the distribution of the residence time of liquid in the mixer do not contribute significantly to the variance of the outlet random signal of the mixer. Further, a good agreement has been proven between the experimental data and the model relationship for the smoothing effect of the mixer based on the application of the gamma distribution of the residence time.

Microchannel Condensation: Comparison of Annular Laminar Flow Theory With Detailed Measurements

2013 ◽  
Author(s):  
H. S. Wang ◽  
J. W. Rose
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Laminar Flow ◽  
Local Heat ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Two Fluids ◽  
Wide Range ◽  
Local Heat Flux ◽  
Good Agreement

Detailed experimental investigations of condensation in microchannels where local heat flux and surface temperature were measured along the channel are compared with theoretical results for the special case of annular, laminar flow. The theoretical model includes surface tension driven transverse flow towards the corners of the channel as well as shear stress driven streamwise flow in an otherwise Nusselt treatment. The theory has no empirical input. When distributions along the channel of the local vapor and wall temperatures are given, local heat flux and heat-transfer coefficient, as well as local vapor quality, may be calculated. Such detailed experimental data have only recently become available. Strict implementation of the theory requires that the onset of condensation occurs within the channel, i.e. the vapor is saturated or superheated at the inlet. The comparisons show remarkably good agreement with the experimental data for two fluids and covering a wide range of experimental conditions.

Combustion Simulation of Propane/Oxygen (With Nitrogen/Argon) Mixtures Using Rate-Controlled Constrained-Equilibrium

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Guangying Yu ◽  
Hameed Metghalchi ◽  
Omid Askari ◽  
Ziyu Wang
Keyword(s):  
Experimental Data ◽  
Energy System ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Oxygen Mixture ◽  
Free Valence ◽  
Wide Range ◽  
Constrained Equilibrium ◽  
Rate Controlled ◽  
Good Agreement

The rate-controlled constrained-equilibrium (RCCE), a model order reduction method, has been further developed to simulate the combustion of propane/oxygen mixture diluted with nitrogen or argon. The RCCE method assumes that the nonequilibrium states of a system can be described by a sequence of constrained-equilibrium states subject to a small number of constraints. The developed new RCCE approach is applied to the oxidation of propane in a constant volume, constant internal energy system over a wide range of initial temperatures and pressures. The USC-Mech II (109 species and 781 reactions, without nitrogen chemistry) is chosen as chemical kinetic mechanism for propane oxidation for both detailed kinetic model (DKM) and RCCE method. The derivation for constraints of propane/oxygen mixture starts from the eight universal constraints for carbon-fuel oxidation. The universal constraints are the elements (C, H, O), number of moles, free valence, free oxygen, fuel, and fuel radicals. The full set of constraints contains eight universal constraints and seven additional constraints. The results of RCCE method are compared with the results of DKM to verify the effectiveness of constraints and the efficiency of RCCE. The RCCE results show good agreement with DKM results under different initial temperature and pressures, and RCCE also reduces at least 60% CPU time. Further validation is made by comparing the experimental data; RCCE shows good agreement with shock tube experimental data.

MAGNETIC BODY FORCE

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1205-1208 ◽  
Author(s):  
A. F. BAKUZIS ◽  
KEZHENG CHEN ◽  
WEILI LUO ◽  
HONGZHANG ZHUANG
Keyword(s):  
Experimental Data ◽  
Magnetic Fluid ◽  
Magnetic Force ◽  
Body Force ◽  
Wide Range ◽  
Magnetic Body Force ◽  
Good Agreement

We have studied magnetic force on sperical magnetic fluid samples with a wide range of concentrations by pendulum method. The results demonstrate good agreement with Kelvin body force and show that other force expressions clearly deviate from experimental data for large sussceptibility values.

Power–gap relationships in low consistency refining

2019 ◽  
Vol 34 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Jorge Enrique Rubiano Berna ◽  
Mark Martinez ◽  
James Olson
Keyword(s):  
Experimental Data ◽  
Force Sensor ◽  
Pilot Scale ◽  
Mill Scale ◽  
Control Power ◽  
Wide Range ◽  
Theoretical Assumptions ◽  
Mechanical Pulps ◽  
The Relationship ◽  
Good Agreement

Abstract Distance between stationary and rotating refining plates, gap, has a direct and significant impact on refining power. Gap is almost universally used to control power in low consistency refining operations. The relationship between power and gap are affected by refiner size, pulp type, plate pattern and refining conditions. In this study, a correlation was developed to describe the power–gap relationships at a wide range of refining conditions and furnish. The correlation was developed using pilot-scale refining data of mechanical pulps. Results showed that a properly defined dimensionless power number is suitable to describe refining power as well as to compare different refiners under the same grounds. The developed correlation was also used to predict mill-scale refining data showing good agreement with between predicted and measured values. Finally, experimental data from force sensor measurements supports the correlation’s theoretical assumptions.

THE DIFFUSION OF A HIGHLY IONIZED PLASMA ACROSS A MAGNETIC FIELD

1965 ◽  
Vol 43 (5) ◽  
pp. 855-871 ◽  
Author(s):  
O. D. Olson ◽  
H. M. Skarsgard
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Inhomogeneous Magnetic Field ◽  
Experimental Conditions ◽  
Degree Of Ionization ◽  
Coulomb Collisions ◽  
Wide Range ◽  
Small Collection ◽  
Toroidal Chamber ◽  
Good Agreement

The decay of electron density and temperature has been measured in a low-pressure helium afterglow by means of double floating probes of very small collection area. The plasma was contained in a glass toroidal chamber; initial gas pressures were in the vicinity of 0.030 Torr. Magnetic confining fields from 0.004 to 0.0860 Wb/m2 were used and the degree of ionization was such that coulomb collisions were dominant. Strict criteria were adopted to ensure reliable operation of the double probes. A theory of diffusion is presented which includes interactions between all species of particles. Drift effects due to the inhomogeneous magnetic field are important at the higher field strengths and are taken into account. Reasonably good agreement is found between the theoretical and observed time constants for electron-density decay over a wide range of experimental conditions.

Relationship between growth rate and undercooling in Pt-added Y1Ba2Cu3O7−x

1996 ◽  
Vol 11 (5) ◽  
pp. 1114-1119 ◽  
Author(s):  
A. Endo ◽  
H. S. Chauhan ◽  
Y. Nakamura ◽  
Y. Shiohara
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Parabolic Equation ◽  
Growth Rates ◽  
Crystal Size ◽  
Experimental Conditions ◽  
Seed Crystals ◽  
Cooling Method ◽  
Increasing Trend ◽  
Good Agreement

Y1Ba2Cu307−x (Y123) crystals were grown by two different methods, the constant undercooling solidification and the continual cooling method, with top seeding by Sm123 seed crystals in order to investigate a relationship between undercooling (ΔT) and a growth rate (R). The crystals of Y123 with a sharp faceted interface, which consisted of {100} and {001} faces, grew epitaxially from the seed. It was found that the growth rates of {100} face (Ra) and that of {001} face (Rc) showed an increasing trend with increasing ΔT, and Rc was faster than Ra within these experimental conditions, ΔT < 20 K. The relation between R and ΔT follows the parabolic equation, viz. Ra ∝ ΔT1.9 and Rc ∝ ΔT1.3 for {100} and {001} faces, respectively. The simulated crystal size using the R and ΔT relations obtained from the constant undercooling method showed good agreement with experimental data by the continual cooling.

On the Minimum Film Boiling Conditions for Spherical Geometries

1980 ◽  
Vol 102 (2) ◽  
pp. 335-341 ◽  
Author(s):  
F. S. Gunnerson ◽  
A. W. Cronenberg
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Flat Plate ◽  
Analytical Method ◽  
Boiling Point ◽  
Film Boiling ◽  
Heater Surface ◽  
Wide Range ◽  
Minimum Heat ◽  
Good Agreement

An analytical method is presented for predicting the minimum heater temperature and the minimum heat flux at the onset of film boiling for spherical and flat plate heaters in saturated and subcooled liquids. Consideration is given to a variety of factors known to affect the minimum film boiling point, including transient liquid-heater contact, interfacial wettability, heater geometry, and liquid subcooling. The theoretical correlations developed are the first known predictions for spherical geometries. A comparison of theory with experimental data indicates good agreement for the minimum heat flux and the minimum film boiling temperature. Results indicate that the minimum conditions may span a wide range depending upon the thermophysical nature of the heater surface and the boiling liquid.

VLE Determination of Carbon Dioxide Loaded Aqueous Alkanolamine Mixtures Using Modified Kent Eisenberg Model

2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Humbul Suleman ◽  
Abdulhalim Shah Maulud ◽  
Zakaria Man
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Model Parameters ◽  
Thermodynamic Models ◽  
Carbon Dioxide Absorption ◽  
Proposed Model ◽  
Wide Range ◽  
Experimental Values ◽  
Good Agreement

AbstractA computationally simple thermodynamic framework has been presented to correlate the vapour-liquid equilibria of carbon dioxide absorption in five representative types of alkanolamine mixtures. The proposed model is an extension of modified Kent Eisenberg model for the carbon dioxide loaded aqueous alkanolamine mixtures. The model parameters are regressed on a large experimental data pool of carbon dioxide solubility in aqueous alkanolamine mixtures. The model is applicable to a wide range of temperature (298–393 K), pressure (0.1–6000 kPa) and alkanolamine concentration (0.3–5 M). The correlated results are compared to the experimental values and found to be in good agreement with the average deviations ranging between 6% and 20%. The model results are comparable to other thermodynamic models.

Establishment of a High Quality Database for the Acoustic Modeling of Perforated Liners

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Claus Lahiri ◽  
Lars Enghardt ◽  
Friedrich Bake ◽  
Sermed Sadig ◽  
Miklós Gerendás
Keyword(s):  
Experimental Data ◽  
Acoustic Modeling ◽  
Acoustic Model ◽  
Acoustic Parameters ◽  
High Quality ◽  
Wide Range ◽  
Bias Flow ◽  
Acoustic Instabilities ◽  
Parameter Influence ◽  
Good Agreement

Perforated liners, especially in combination with a bias flow, are very effective sound absorbers. When appplied to gas turbine combustors, they can suppress thermo-acoustic instabilities and thus allow the application of new combustion concepts concerning higher efficiency and lower emissions. While the successful application of such a damping concept has been shown, it is still not possible to accurately predict the damping performance of a given configuration. This paper provides a comprehensive database of high quality experimental data. Variations of geometric, fluid mechanic, and acoustic parameters have been studied, including realistic engine configurations. The results demonstrate each parameter influence on the damping performance. A low order thermo-acoustic model is used to simulate the test configurations numerically. The model shows a good agreement with the measurements for a wide range of geometries and Strouhal and bias flow Mach numbers.

scholarly journals Photochemical laws and visual phenomena

1946 ◽  
Vol 133 (870) ◽  
pp. 63-75 ◽  
Keyword(s):  
Experimental Data ◽  
Recovery Process ◽  
Visual Sensitivity ◽  
Rapid Recovery ◽  
Foveal Vision ◽  
Experimental Conditions ◽  
Reciprocity Law ◽  
Wide Range ◽  
Visual Phenomena ◽  
Nervous Transmission

By measuring the course of recovery of visual sensitivity in the dark, after exposure to light, it has been demonstrated that all the phenomena of recovery can be explained—qualitatively—by the known fundamental principles of photochemistry. In particular, the reciprocity law, which is widely valid in photographic processes, only holds under certain limited circumstances for visual phenomena. In the case of foveal vision the reciprocity law does not hold, owing to the rapid recovery process, except for very brief periods of exposure. In the case of parafoveal vision the recovery process for the scotopic mechanism is sufficiently slow to allow validity of the reciprocity law over a wide range of exposure periods, although the law still breaks down for the parafoveal photopic mechanism. This circumscribed validity of the reciprocity law is of practical service in that the effect of many experimental conditions can be predicted from a very limited set of suitably chosen experimental data. It may be noted that it has not been found necessary to introduce any postulate involving recovery of the nervous transmission system as part of the recovery process.

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