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.

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.

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 g Factors for Co2+ in MgO and CaO Crystals

2001 ◽  
Vol 56 (3-4) ◽  
pp. 249-252 ◽  
Author(s):  
Shao-Yi Wu ◽  
Wen-Chen Zheng
Keyword(s):  
Configuration Interaction ◽  
Optical Spectra ◽  
Theoretical Studies ◽  
Cluster Approach ◽  
Experimental Values ◽  
Good Agreement ◽  
G Factors

Abstract This paper presents a cluster approach to the calculation of the g factors for 3d7 ions in cubic oc­ tahedral crystals, in which the parameters related to the configuration interaction and the covalency reduction effects are obtained from optical spectra of the studied crystals, and so no adjustable parameters are applied. From the approach, the g factors for MgO:Co2+ and CaO:Co2+ are cal­culated. The calculated results show good agreement with the observed values. The experimental values of g 4.333 for CaO:Co2+ are also explained.

Combined excitatory and inhibitory coupling in a 1-D array of Belousov–Zhabotinsky droplets

2014 ◽  
Vol 16 (22) ◽  
pp. 10965-10978 ◽  
Author(s):  
Ning Li ◽  
Jorge Delgado ◽  
Hector O. González-Ochoa ◽  
Irving R. Epstein ◽  
Seth Fraden
Keyword(s):  
Malonic Acid ◽  
Drop Size ◽  
Theoretical Studies ◽  
Inhibitory Coupling ◽  
Experimental And Theoretical Studies

Experimental and theoretical studies of the coupling between Belousov–Zhabotinsky droplets in oil as a function of malonic acid, drop size, drop spacing, and time.

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.

scholarly journals Modeling of Hydrodynamics in a 25 mm ϕ Pulsed Disk and Doughnut Column

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Rajnish Kumar ◽  
D. Sivakumar ◽  
Shekhar Kumar ◽  
U. Kamachi Mudali
Keyword(s):  
Slip Velocity ◽  
Drop Size ◽  
Absolute Error ◽  
Model Parameters ◽  
Dispersed Phase ◽  
Acid System ◽  
Hydrodynamic Parameters ◽  
Predicted Values ◽  
Experimental Values ◽  
Good Agreement

The hydrodynamic parameters, namely, dispersed phase holdup and flooding throughput, have been investigated in 25 mm diameter pulsed disk and doughnut column (PDDC), in no mass transfer conditions. In this work, using existing correlations on plate pulsed columns, the dispersed phase holdup and the flooding throughput are empirically modelled well using the slip velocity concept. A good agreement is observed between experimental values and predicted values obtained from empirical correlation. The experimental data for dispersed phase holdup and flooding throughput has been modelled using the Van Delden model to describe the hydrodynamics characteristics of a PDDC and necessary adjustable parameters for drop size distribution and dispersed phase holdup are updated for 30% TBP-nitric acid system. The model parameters were estimated by minimizing the absolute error between experimental and theoretical values of flooding throughput and holdup data. It was found that the measured values and observed trends could be described accurately using this model after fitting holdup and flooding data. The error between the experimental and theoretical values of flooding throughput and holdup was found to be less than 10%.

scholarly journals Simulation and experimental studies on the evolution of a laser spark in air

1992 ◽  
Vol 10 (4) ◽  
pp. 707-713 ◽  
Author(s):  
X. C. Zeng ◽  
D. P. Singh ◽  
V. Palleschi ◽  
A. Salvetti ◽  
M. De Rosa ◽  
...  
Keyword(s):  
Shock Waves ◽  
Experimental Studies ◽  
Numerical Code ◽  
Radiation Hydrodynamics ◽  
Theoretical Studies ◽  
Air Plasma ◽  
Hot Plasma ◽  
Laser Spark ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Experimental and theoretical studies on the evolution of shock waves in air plasma induced by laser spark have been carried out. The systematic study of the shock wave has been performed experimentally and 1-D numerical code of radiation hydrodynamics (1-DRHC) has been used to simulate the later stage of laser spark in air. The numerical results on the propagation of shock waves and the expansion of hot plasma are presented and subsequent results on the first divergent and convergent shock waves are found to be in good agreement with the experimental data.

Sign in / Sign up

Export Citation Format

Share Document