Theoretical Investigation of the Switching Mechanism in a Bistable Wall Attachment Fluid Amplifier

1971 ◽  
Vol 93 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M. Epstein
Keyword(s):  
Theoretical Investigation ◽  
Experimental Results ◽  
Turbulent Jet ◽  
Switching Behavior ◽  
Switching Mechanism ◽  
Switching Times ◽  
Experimental Values ◽  
End Wall ◽  
Good Agreement

A theory based on turbulent jet entrainment properties is presented for the prediction of unsteady end wall switching behavior in a bistable wall attachment fluid amplifier. Good agreement is obtained between theoretically predicted switching times and experimental results. The analysis also indicates the experimentally observed dwell phenomena and computed dwell times compare well with reported experimental values.

scholarly journals Trajectory and Spreading of a Turbulent Jet in the Presence of a Crossflow of Arbitrary Velocity Distribution

1969 ◽  
Author(s):  
W. W. Bowley ◽  
J. Sucec
Keyword(s):  
Velocity Distribution ◽  
Velocity Component ◽  
Constant Velocity ◽  
Experimental Results ◽  
Turbulent Jet ◽  
Special Cases ◽  
Arbitrary Velocity ◽  
Good Agreement

The trajectory and spreading of a turbulent circular jet of air issuing from a wall in a perpendicular or near perpendicular fashion into a crossflow whose velocity component along the wall may vary arbitrarily in the direction normal to the wall is treated in a semianalytic fashion. The method of attack on the problem was instigated by the work of Abramovich on the turbulent circular jet of air in a constant velocity crossflow. Results for the trajectories and spreading are presented for the two special cases of a constant velocity crossflow and a crossflow whose velocity varies linearly in a direction normal to the wall. For the constant velocity case, experimental results are available in Abramovich and the analysis undertaken here shows good agreement with those results.

Atomistic Simulation for the Site Preference of Tb3(Fe28-XCoX)V1.0 Compounds

2012 ◽  
Vol 535-537 ◽  
pp. 1015-1018
Author(s):  
Jing Sun ◽  
Shuo Huang ◽  
Jiang Shen ◽  
Ping Qian
Keyword(s):  
Rare Earth ◽  
Structural Properties ◽  
Atomistic Simulation ◽  
Experimental Results ◽  
Inversion Method ◽  
Site Preference ◽  
Lattice Constants ◽  
Pair Potentials ◽  
Experimental Values ◽  
Good Agreement

The effect of cobalt on the structural properties of intermetallic Tb3(Fe28-xCox)V1.0with Nd3(Fe,Ti)29structure has been studied by using interatomic pair potentials obtained through the lattice inversion method. Calculated results show that the order of site preference of cobalt is 8j(Fe8), 4e(Fe11) and 2c(Fe1) which is in good agreement with experimental results. And the calculated lattice constants coincide quite well with experimental values. All these prove the effectiveness of interatomic pair potentials obtained through the lattice inversion method in the description of rare-earth materials.

Understanding of flow features over a typical crew module at Mach 4

2015 ◽  
Vol 119 (1216) ◽  
pp. 727-746 ◽  
Author(s):  
S. L. N. Desikan ◽  
M. M. Patil ◽  
S. Subramanian
Keyword(s):  
Experimental Results ◽  
Leeward Side ◽  
Wake Vortex ◽  
Aerodynamic Coefficients ◽  
Near Wake ◽  
Sonic Line ◽  
Oil Flow ◽  
Flow Features ◽  
Experimental Values ◽  
Good Agreement

AbstractThis paper presents the numerical simulations of flowfield over a typical Crew Module at Mach 4 for different angles-of-attack ranging from 0 to –25°. Detailed flow features such as contour of density gradient over the model, numerical oil flow and near wake vortex structures are captured very well in the present simulations. The location of the sonic line and its behaviour due to angles-of-attack is also captured in the simulations. TheCPdistribution on the windward and leeward side shows excellent match with the experimental results. Also, the prediction of aerodynamic coefficients shows very good agreement with the experimental results. The numerical simulation predictsCMcg,CNandCAwithin 8%, 4% and 3·5% respectively with respect to experimental values.

An Analytical Examination of the Combustion of a Turbulent Jet in an Environment of Air Containing a Premixed Fuel or a Diluent

1995 ◽  
Vol 117 (3) ◽  
pp. 234-238 ◽  
Author(s):  
P. Wierzba ◽  
G. A. Karim ◽  
I. Wierzba
Keyword(s):  
Flame Length ◽  
Turbulent Jet ◽  
Simple Analytical Model ◽  
Flammability Limits ◽  
Gaseous Fuels ◽  
Gaseous Environment ◽  
Fuel Jet ◽  
Predicted Values ◽  
Experimental Values ◽  
Good Agreement

A simple analytical model for the mixing and combustion of an axisymmetric turbulent gaseous fuel jet discharging into a co-flowing streaming gaseous environment of an auxiliary fuel and/or a diluent homogeneously mixed with air is presented. A number of gaseous fuels and diluents are considered. It is shown that the combustion characteristics of a fuel jet can be modified significantly by the presence of a relatively small amount of a fuel in the surrounding air at concentrations well below the corresponding local flammability limits. Correlative procedures are presented for estimating changes in the flame length, the size of the combustion zone, and the blowout limits with changes in the type and concentration of the fuel in the surroundings. Predicted values showed generally good agreement with the corresponding experimental values.

Modeling and Dynamic Evaluation of a Two-Stage Two-Spool Servovalve Used for Pressure Control

1991 ◽  
Vol 113 (4) ◽  
pp. 709-713 ◽  
Author(s):  
S. T. Tsai ◽  
A. Akers ◽  
S. J. Lin
Keyword(s):  
Mathematical Model ◽  
Control Valve ◽  
Pressure Control ◽  
Experimental Results ◽  
Two Stage ◽  
Dynamic Evaluation ◽  
Second Stage ◽  
Experimental Values ◽  
Pressure Control Valve ◽  
Good Agreement

Experimental results for a unique design of a two-spool pressure control valve were reported by Anderson (1984). The first stage is a dynamically stable flapper-nozzle valve for which a mathematical model is already available (Lin and Akers, 1989a). For the second stage, however, which consists of two parallel spools in a common body, no such model existed. The purpose of this paper was therefore to construct such a model and to compare results calculated from it to experimental values. Moderately good agreement with experimental values was obtained.

Study on Absorption Rate of Phosphorus for Hypereutectic Al-Si Alloy Modified with Cu-P

2014 ◽  
Vol 794-796 ◽  
pp. 112-117 ◽  
Author(s):  
Gu Zhong ◽  
Zhi Bin Wu ◽  
Chu Qiu ◽  
Ya Fang Li ◽  
Hiromi Nagaumi
Keyword(s):  
Process Parameters ◽  
Master Alloy ◽  
Absorption Rate ◽  
Reaction Rate ◽  
Process Condition ◽  
Experimental Results ◽  
Degree Of Reaction ◽  
Experimental Values ◽  
Good Agreement

In this paper, the effects of process parameters on the absorption rate of P for hypereutectic Al-Si alloy (A390) which modified with Cu-14%P master alloy were systematically studied. And the mechanism that the process parameters play a role in effecting on the absorption rate of P was deeply investigated. The results indicated that the absorption rate of P increased with the increase of modified time and temperature, and decreased with the increase of the amount of added P. Under the same process condition, P added in form of Cu-14%P particles can cause to obtain the higher absorption rate of P than that of Cu-14%P powders. According to the experimental results, an equation on changes of the absorption rate of P was proposed, and the results show that good agreement is obtained between calculated and experimental values. The process parameters played a role in effecting on the absorption rate of P mainly through affecting the reaction rate of forming AlP particles in the melt, as well as the degree of reaction reached.

Turbulent Jet Diffusion Flames in Environments Containing Some Premixed Fuel

1988 ◽  
Vol 110 (3) ◽  
pp. 146-150 ◽  
Author(s):  
M. G. Kibrya ◽  
G. A. Karim
Keyword(s):  
Diffusion Flame ◽  
Diffusion Flames ◽  
Turbulent Jet ◽  
Gaseous Fuels ◽  
Model Based ◽  
Jet Diffusion Flames ◽  
Experimental Values ◽  
Additional Fuel ◽  
Good Agreement

The blowout limit of a methane jet diffusion flame is extended by adding small concentrations of a fuel to the surrounding air. The improvement is predicted theoretically with a model based on the stoichiometric changes within the jet and in its vicinity due to the presence of this additional fuel. Good agreement was obtained between such a prediction and the corresponding experimental values for a range of gaseous fuels in the surrounding air.

Separation of CO2 by Using Aqueous Mixtures of AMP and [B3MPYR][BF4] at High Pressure

2014 ◽  
Vol 67 (4) ◽  
Author(s):  
Syamila Nordin ◽  
Ruzitah Mohd Salleh ◽  
Norhuda Ismail
Keyword(s):  
Absorption Capacity ◽  
Experimental Results ◽  
Co2 Absorption ◽  
Loading Capacity ◽  
Aqueous Mixtures ◽  
Simple Correlation ◽  
Separation Of Co2 ◽  
Predicted Values ◽  
Experimental Values ◽  
Good Agreement

In this study, CO2 absorption capacity in aqueous mixtures of 2-amino-2-methyl-1-propanol, (AMP) and N-butyl-3-methylpyridinium tetrafluoroborate, [B3MPYR][BF4] was measured at pressures from 200 kPa up to 5000 kPa and temperatures of 303.15 K - 333.15 K. The AMP concentration was maintained at 1 M while the [B3MPYR][BF4] concentration ranges from 0.05 M to 0.3 M. It was observed that CO2 loading capacity increases when the pressure increased. However, increasing of temperature will decrease the CO2 loading. From the experimental results, a simple correlation, as suggested by Jou and Mather was used to predict the CO2 loading in the aqueous AMP-[B3MPYR][BF4] mixtures. The model were found to be in a good agreement with the experimental results where only 1.66% of the predicted values deviate more than 20% compared to the experimental values.

scholarly journals Isomer ratios for the 88Sr(p,xn) and 88Sr(p,p3n) reactions

1967 ◽  
Vol 45 (22) ◽  
pp. 2711-2721 ◽  
Author(s):  
D. R. Sachdev ◽  
L. Yaffe
Keyword(s):  
Statistical Model ◽  
Spin Density ◽  
Cross Section ◽  
Experimental Results ◽  
Density Parameter ◽  
Model Calculations ◽  
Experimental Values ◽  
Parameter Values ◽  
Good Agreement

Isomeric cross-section ratios for nuclides formed from (p,2n), (p,3n), (p,4n), and (p,p3n) reactions on 88Sr are presented. The experimental results for the 88Sr(p,2n)87Ym,g reaction are compared with statistical-model calculations wherein spin-density parameter values were obtained from various theoretical formalisms. The parameters required to match the calculated and experimental values are in good agreement with those obtained by Vandenbosch et al.

scholarly journals LES of spray in crossflow – Effect of droplet distortion

2016 ◽  
Vol 9 (1) ◽  
pp. 55-70 ◽  
Author(s):  
Anubhav Sinha ◽  
RV Ravikrishna
Keyword(s):  
Initial Conditions ◽  
Spherical Shape ◽  
Experimental Results ◽  
Mass System ◽  
Large Eddy ◽  
Droplet Sizes ◽  
Experimental Values ◽  
Early Breakup ◽  
Drag Law ◽  
Good Agreement

The present investigation is focused on modeling of spray in crossflow using Large Eddy Simulations (LES). The modeling efforts are supported by experiments which are used both to provide accurate boundary and initial conditions and to evaluate droplet shapes in the near nozzle region. The droplets are modeled as Lagrangian parcels in an Eulerian continuum. Droplets in such configuration have been found to be distorted and not in perfect spherical shape from experimental results of our previous study. Droplet distortion is computed by Taylor-Analogy Breakup (TAB) distortion model. Each droplet is modelled as damped spring-mass system, where surface tension acts as a spring on the mass of the droplet and viscous dissipation provides the damping effect. The effort is to examine the effect of drag law used and the effect of this distortion on the droplet sizes produced in the flow field. Spray wind-ward trajectory and droplet sizes obtained from simulations are compared with the experimental results available. Although computational spray trajectory shows a reasonable match with experimental values, droplet sizes using the standard TAB model are found to be larger than that from experimental observation. To account for this distortion and its role in early breakup of droplets, constants of the TAB model are modified and the droplet sizes are found to be in good agreement with the experimental data.

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