Flame Blowoff Studies Using Large-Scale Flameholders

1982 ◽  
Vol 104 (4) ◽  
pp. 853-857 ◽  
Author(s):  
K. V. L. Rao ◽  
A. H. Lefebvre
Keyword(s):  
Experimental Data ◽  
Large Scale ◽  
Water Injection ◽  
Injection Technique ◽  
Theoretical Studies ◽  
Effective Pressure ◽  
Test Program ◽  
Combustible Mixtures ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Experimental and theoretical studies are made of the factors governing the blowoff velocities of stabilized flames supplied with flowing gaseous combustible mixtures. The test program includes wide variations in effective pressure, obtained using the water injection technique, and also covers wide ranges of velocity, flameholder size, and flameholder blockage. An equation is derived for predicting blowoff velocities which shows good agreement with the experimental data.

Weak Extinction Limits of Turbulent Heterogeneous Fuel/Air Mixtures

1980 ◽  
Vol 102 (2) ◽  
pp. 416-421 ◽  
Author(s):  
D. R. Ballal ◽  
A. H. Lefebvre
Keyword(s):  
Liquid Fuel ◽  
Drop Size ◽  
Air Pressure ◽  
Theoretical Studies ◽  
Turbulence Level ◽  
Test Program ◽  
Stabilized Flames ◽  
Experimental Values ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Experimental and theoretical studies are made of the factors governing the weak extinction limits of stabilized flames supplied with flowing mixtures of liquid fuel drops and air. The test program includes wide variations in inlet air pressure, velocity and turbulence level, and also covers wide ranges of fuel volatility and mean drop size. The influence of flameholder size and blockage is also examined. An equation is derived for predicting weak extinction limits which shows good agreement with the corresponding experimental values.

scholarly journals Weak Extinction Limits of Turbulent Heterogeneous Fuel/Air Mixtures

1979 ◽  
Author(s):  
D. R. Ballal ◽  
A. H. Lefebvre
Keyword(s):  
Liquid Fuel ◽  
Drop Size ◽  
Air Pressure ◽  
Theoretical Studies ◽  
Turbulence Level ◽  
Test Program ◽  
Stabilized Flames ◽  
Experimental Values ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Experimental and theoretical studies are made of the factors governing the weak extinction limits of stabilized flames supplied with flowing mixtures of liquid fuel drops and air. The test program includes wide variations in inlet air pressure, velocity and turbulence level, and also covers wide ranges of fuel volatility and mean drop size. The influence of flameholder size and blockage is also examined. An equation is derived for predicting weak extinction limits which shows good agreement with the corresponding experimental values.

Formation of solitons in transitional boundary layers: theory and experiment

1993 ◽  
Vol 251 ◽  
pp. 273-297 ◽  
Author(s):  
Y. S. Kachanov ◽  
O. S. Ryzhov ◽  
F. T. Smith
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Asymptotic Theory ◽  
Subsequent Development ◽  
Boundary Layer Transition ◽  
Theoretical Studies ◽  
Layer Transition ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

This work brings together experimental and theoretical studies of nonlinear stages aimed at the K-regime in boundary-layer transition, and some combined theoretical and experimental results are discussed. It is shown that the initial stages in the formation of so-called spikes, observed in many experiments, may be described very well by the asymptotic theory. These flashes-spikes are shown to be (in certain regimes) possible solitons of the boundary layer and governed by the integral-differential Benjamin-Ono equation. Properties of the spike-solitons, obtained both theoretically and experimentally in the quasi-planar stages of their development, are presented. Features of the disturbance behaviour connected with the subsequent development of three-dimensionality are also discussed, as are the effects of viscosity and shorter lengthscales. The main conclusion of the work concerns the hypothesis of the possible soliton nature of the flashes-spikes (within limits), which seems reliably corroborated by the good agreement found between the theory and the experimental data.

Morphology of Voltage-Triggered Ordered Wrinkles of a Dielectric Elastomer Sheet

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Guoyong Mao ◽  
Lei Wu ◽  
Xueya Liang ◽  
Shaoxing Qu
Keyword(s):  
High Voltage ◽  
Optical Sensor ◽  
Material Science ◽  
Dielectric Elastomer ◽  
Theoretical Studies ◽  
Science And Engineering ◽  
Future Design ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

Wrinkles widely existing in sheets and membranes have attracted a lot of attention in the fields of material science and engineering applications. In this paper, we present a new method to generate ordered (striplike) and steady wrinkles of a constrained dielectric elastomer (DE) sheet coated with soft electrodes on both sides subjected to high voltage. When the voltage reaches a certain value, wrinkles will nucleate and grow. We conduct both experimental and theoretical studies to investigate the wavelength and amplitude of the wrinkle. The results show a good agreement between theory and experiment. Moreover, the amplitude and wavelength of ordered wrinkles can be tuned by varying the prestretch and geometry of the DE sheet, as well as the applying voltage. This study can help future design of DE transducers such as diffraction grating and optical sensor.

Theoretical studies of the anisotropic g factors for deoxygenated Y123

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542017
Author(s):  
L. J. Zhang ◽  
S. Y. Wu ◽  
C. C. Ding ◽  
Y. K. Cheng
Keyword(s):  
Experimental Data ◽  
Orbit Coupling ◽  
Theoretical Studies ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Ligand Orbital ◽  
Y123 System ◽  
Good Agreement ◽  
G Factors

The anisotropic [Formula: see text] factors of the deoxygenated YBaCuO (Y123) are theoretically studied using the perturbation formulas of the [Formula: see text] factors for a tetragonally elongated octahedral [Formula: see text] cluster. The ligand orbital and spin-orbit coupling contributions are included from the cluster approach in view of covalency. The calculated [Formula: see text] factors show good agreement with the experimental data. The anisotropy of the [Formula: see text] factors is analyzed by considering the local tetragonal elongation distortion around this five-fold coordinated [Formula: see text] site in the deoxygenated Y123 system.

Numerical Simulation and Experimental Study of Particle Dynamics in a Rotating Drum with Flights

2017 ◽  
Vol 899 ◽  
pp. 65-70 ◽  
Author(s):  
Suellen Mendonça Nascimento ◽  
F.P. de Lima ◽  
Claudio Roberto Duarte ◽  
Marcos Antonio de Souza Barrozo
Keyword(s):  
Experimental Data ◽  
Granular Flow ◽  
Numerical Study ◽  
Operating Conditions ◽  
Particle Dynamic ◽  
Multiphase Model ◽  
Theoretical Studies ◽  
Rotating Drum ◽  
Dynamics Of Particles ◽  
Good Agreement

Rotary dryers are widely used in various industries. Although numerous research efforts have focused on characterizing the dynamics of these equipments, the design of rotating dryers is complex, and theoretical studies are necessary to gain an in-depth understanding of the dynamics of particles in these dryers. This paper aims to investigate the particle dynamic behavior in a rotating drum with flights, based on CFD and experimental results. In the numerical study it was used the Eulerian-Eulerian multiphase model along with the kinetic theory of granular flow. The holdups of solids in the flights were compared with experimental data, using a methodology created specifically for this purpose. The simulated results were in good agreement with the experimental data and the present work has shown that the Eulerian approach has been able to predict the fluid dynamics behavior in different operating conditions.

scholarly journals Experimental and theoretical studies of the behaviour of slow electrons in air. II. Ionospheric and other applications

1949 ◽  
Vol 196 (1046) ◽  
pp. 427-435 ◽  
Keyword(s):  
Experimental Data ◽  
Free Electron ◽  
Laboratory Data ◽  
Wave Interaction ◽  
Theoretical Studies ◽  
Radio Waves ◽  
Electronic Motion ◽  
Slow Electrons ◽  
Experimental And Theoretical Studies

The significance, for ionospheric and other studies, of the experimental data given in part I is considered. It is shown how the data obtained from rocket soundings may be combined with the measurements of wave interaction in the ionosphere and the laboratory data given in part I, to estimate the height at which wave interaction occurs and the collisional frequency at that height. The following topics are also discussed: the theory of electronic motion in direct and alternating fields; the power communicated to a free electron in a gas by an alternating field; and the interaction of radio waves in the ionosphere.

scholarly journals STUDIES OF PHOTOIONIZATION PROCESSES OF NITROGEN-LIKE O+ION USINGTHE SCREENING CONSTANT BY UNIT NUCLEAR CHARGEMETHOD

2021 ◽  
Vol 9 (09) ◽  
pp. 977-985
Author(s):  
Babou Diop ◽  
◽  
Abdou Diouf ◽  
Youssou Gning ◽  
Maurice Faye ◽  
...  
Keyword(s):  
Experimental Data ◽  
Metastable State ◽  
Effective Charge ◽  
Nuclear Charge ◽  
Theoretical Studies ◽  
Rydberg Series ◽  
Screening Constant ◽  
Semi Empirical ◽  
Experimental And Theoretical Studies ◽  
Theoretical Results

In this present work, we have calculated the energies positions of the 2s22p2(1D)nd2P, 2s22p2(1D)nd2S, 2s22p2(1D)ns 2D, 2s22p2(1S)nd2D and 2s2p3(3P)np2D Rydberg series in the photoionization spectra from the 2P° metastable state of the O+ ion. Calculations were performed up to n = 40 applyingthe Screening Constant by Unit Nuclear Charge (SCUNC) via its semi empirical formalism. The quantum defect and the effective charge are also calculated.The results agree within 98% to Aguilars experimental data, and with Sows theoretical results to within 99%. These data can be a useful guideline for future experimental and theoretical studies.

scholarly journals The deformability of the stress-strained concrete strips between the cracks during the short-term dynamic loading

2020 ◽  
Vol 315 ◽  
pp. 07002
Author(s):  
Zaur Galyautdinov ◽  
Oleg Kumpyak ◽  
Daud Galyautdinov
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Dynamic Loading ◽  
Experimental Research ◽  
Inclination Angle ◽  
Dynamic Load ◽  
Statistic Analysis ◽  
Theoretical Studies ◽  
Short Term ◽  
Experimental And Theoretical Studies

The formation of non-intersecting cracks in stress-strained ferroconcrete elements leads to separation of concrete strips between the cracks. The results of the experimental research indicate a significant decrease of the durability and deformability of the stress-strained concrete strips between cracks both under static and short-term dynamic loading. At the same time physico-mechanical properties depend on the straining deformations and rebars’ inclination angle towards the cracks. The existing theoretical and experimental results evaluate only the durability of the concrete strips between the cracks. The current paper presents the results of experimental and theoretical studies on the dynamic deformability of the stress-strained discs between the cracks. The statistic analysis of the experimental data is done; on the basis of the analysis we suggest the dependencies, characterizing the deformability of the concrete strips during the short-term dynamic load depending on the level of the straining deformations and rebars’ inclination angle towards the cracks.

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