Detonation Cell Widths in Hydrogen/Oxygen/Diluent Mixtures at Low Initial Pressures

1995 ◽  
Vol 117 (1) ◽  
pp. 13-17
Author(s):  
R. K. Kumar ◽  
W. A. Dewit
Keyword(s):  
Initial Temperature ◽  
Internal Diameter ◽  
Detonation Cell ◽  
Post Shock ◽  
Induction Times ◽  
Smoked Foil ◽  
Foil Technique ◽  
Good Agreement

Detonation cell widths of hydrogen/oxygen/helium/steam mixtures were determined in 15 and 30-cm internal-diameter pipes using the smoked-foil technique. The investigations were carried out over a range of initial pressures from 13.3 to 106.6 kPa and at an initial temperature of 105°C. The concentration range investigated included hydrogen concentrations from 10 to 40 percent and steam concentrations of up to 20 percent. The measured cell widths range from about 1 mm to over 100 mm and were in good agreement with those estimated using the calculated values of induction times and post-shock gas velocities.

Investigation of Quench-16 Experiment With MELCOR Computer Code

2014 ◽  
Author(s):  
Petya Vryashkova ◽  
Pavlin Groudev ◽  
Antoaneta Stefanova
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Initial Temperature ◽  
Computer Code ◽  
Air Flow Rate ◽  
Fuel Rod ◽  
Fuel Bundle ◽  
Oxygen Starvation ◽  
Air Ingress ◽  
Good Agreement

This paper presents a comparison of MELCOR calculated results with experimental data for the QUENCH-16 experiment. The analysis for the air ingress experiment QUENCH-16 has been performed by INRNE. The calculations have been performed with MELCOR code. The QUENCH-16 experiment has been performed on 27-th of July 2011 in the frame of the EC-supported LACOMECO program. The experiments have focused on air ingress investigation into an overheated core following earlier partial oxidation in steam. QUENCH-16 has been performed with limited pre-oxidation and low air flow rate. One of the main objectives of QUENCH-16 was to examine the interaction between nitrogen and oxidized cladding during a prolonged period of oxygen starvation. The bundle is made from 20 heated fuel rod simulators arranged in two concentric rings and one unheated central fuel rod simulator, each about 2.5 m long. The tungsten heaters were surrounded by annular ZrO2 pellets to simulate the UO2 fuel. The geometry and most other bundle components are prototypical for Western-type PWRs. To improve the obtained results it has been made a series of calculations to select an appropriate initial temperature of the oxidation of the fuel bundle and modified correlation oxidation of Zircaloy with MELCOR computer code. The compared results have shown good agreement of calculated hydrogen and oxygen starvation in comparison with test data.

Fluorine mean-life measurements below 1000 Å using the beam–foil technique

1976 ◽  
Vol 54 (10) ◽  
pp. 1014-1021 ◽  
Author(s):  
E. H. Pinnington ◽  
D. J. G. Irwin ◽  
A. E. Livingston ◽  
J. A. Kernahan
Keyword(s):  
Satellite Data ◽  
Wavelength Region ◽  
Wave Functions ◽  
Interstellar Clouds ◽  
Beam Foil ◽  
Foil Technique ◽  
Good Agreement

We have used the beam–foil technique to measure mean lives for 16 transitions in F I–F IV in the wavelength region 400 Å–1000 Å. Good agreement is found with the results of recent calculations, particularly those employing correlated wave functions. The f-value trends for 5 isoelectronic sequences are presented in detail (2p5 2P0–2p43s2 D and 2p5 2P0–2p43s 2P in F I; 2p4 3P–2p33s 3D0 in F II; 2p3 2D0–2s2p4 2D and 2p3 4S0–2s2p4 4P in F III). Our f value for the 955 Å multiplet in F I is also used in conjunction with some new satellite data to show that the fluorine abundance is apparently depleted in interstellar clouds by a factor of at least 3 below its solar value.

An Approximate Model to Calculate Foldover and Strains During Cold Upsetting of Cylinders Part II: Use of the Foldover Model to Estimate Friction

1990 ◽  
Vol 112 (3) ◽  
pp. 267-271 ◽  
Author(s):  
O. M. Ettouney ◽  
K. A. Stelson
Keyword(s):  
Finite Element Analysis ◽  
Approximate Model ◽  
Ring Test ◽  
Internal Diameter ◽  
Cold Upsetting ◽  
Element Analysis ◽  
New Approach ◽  
The Finite Element Analysis ◽  
Friction Calibration ◽  
Good Agreement

This paper addresses an approach to calculate the friction coefficient during nonuniform compression of cylinders. The approach combines new friction-calibration curves (prepared using the finite-element analysis) that relate friction to workpiece shape and the foldover model from Part I. Foldover in upsetting is used in the same way that the change in internal diameter is used in the ring test to determine friction. However, the new approach has the advantage that measurements are taken directly from the workpiece. Comparisons of friction values calculated from the ring test and the new approach showed good agreement.

Beam-foil lifetime measurements for some 2p3nl terms of singly-ionized fluorine

1979 ◽  
Vol 57 (7) ◽  
pp. 1046-1050 ◽  
Author(s):  
Eric H. Pinnington ◽  
Robert N. Gosselin ◽  
David J. G. Irwin ◽  
James A. O'Neill
Keyword(s):  
Wavelength Region ◽  
Lifetime Measurements ◽  
Experimental Values ◽  
Beam Foil ◽  
Foil Technique ◽  
Good Agreement

We have used the beam-foil technique in the wavelength region between 3500 and 4500 Å to measure the lifetimes of 10 terms in F II having the configuration 2p3nl, and also to demonstrate the usefulness of the ANDC method for overcoming the effects of cascade repopulation in these measurements. Our results are in good agreement with theory and with other experimental values.

Beam-foil spectroscopy of oxygen in the wavelength region from 270 to 490 Å

1978 ◽  
Vol 56 (5) ◽  
pp. 508-516 ◽  
Author(s):  
Eric H. Pinnington ◽  
Keith E. Donnelly ◽  
J. Anthony Kernahan ◽  
David J. G. Irwin
Keyword(s):  
Satisfactory Agreement ◽  
Wavelength Region ◽  
Theoretical Predictions ◽  
The Mean ◽  
Theoretical Results ◽  
Beam Foil ◽  
Foil Technique ◽  
Good Agreement

We have used the beam-foil technique to study the spectrum of oxygen between 270 and 490 Å. We have measured the mean lives of the 3d2F, 3d4P, 3d4D, 3d′ 2D, 3d′ 2F, 4d4P, and 4d4D terms of O II, the 3s1P0, 3s3P0, 3S5P, 3s′ 3D, 3d3P, 3d3D, 3d3F, and 3d5P terms of O III, and the 3S2S, 3P2P0, and 3s4P0 terms of O IV. All cascade components are adequately explained. Good agreement is found with previous measurements in most cases, but significant discrepancies are found with some earlier results obtained using branches above 2000 Å. Generally satisfactory agreement is also found with theoretical predictions, although disagreement is found for several members of the 2p3–2p23d array in O II f-Values are computed for 18 individual lines, and compared with other experimental and theoretical results. Finally, we discuss briefly the f-value trends along the 2p23P–2p3s3P0 (O III), 2p21D–2p3s1P0 (O III), 2s2p24P–2s2p(3P0)3s4P0 (O IV), and 2p2P0–3s2S (O IV) isoelectronic sequences.

A Constitutive Model and Its Identification for the Deformation Characterized by Dynamic Recovery

1997 ◽  
Vol 119 (2) ◽  
pp. 138-142 ◽  
Author(s):  
M. Zhou ◽  
M. P. Clode
Keyword(s):  
Constitutive Model ◽  
Deformation Behavior ◽  
Initial Temperature ◽  
Elevated Temperatures ◽  
Dynamic Recovery ◽  
Twist Rate ◽  
Determination Methods ◽  
Hot Torsion ◽  
Nonlinear Iteration ◽  
Good Agreement

A constitutive model is presented to characterize the deformation behavior of materials at elevated temperatures that undergo dynamic recovery. Hot torsion tests were utilized to validate the constitutive equations. The tests were conducted with the material of AA5083 over a range of twist rate from 0.013 to 13.70 rev/s and for each twist rate at an initial temperature range of 350°C to 550°C, respectively. The material constants determination methods are demonstrated with the proposed linear regression and the nonlinear iteration formats. A good agreement between the experimental data and the predicted results has been achieved

X-ray tomography and three-dimensional image analysis of epoxy-glass syntactic foams

2005 ◽  
Vol 364 (1838) ◽  
pp. 69-88 ◽  
Author(s):  
Eric Maire ◽  
Nelly Gimenez ◽  
Valérie Sauvant-Moynot ◽  
Henry Sautereau
Keyword(s):  
Size Distribution ◽  
Volume Fraction ◽  
Hollow Spheres ◽  
Three Dimensional ◽  
Internal Diameter ◽  
Syntactic Foams ◽  
X Ray ◽  
Dimensional Image ◽  
Three Samples ◽  
Good Agreement

Syntactic foams (glass hollow spheres embedded in an epoxy matrix) were produced on purpose to be used as test materials for the present study. Two kinds of spheres (MS1 and MS2) were adjoined to a same polymer matrix, MS1 with a volume fraction of 55 and MS2 with 30 and 55%. The samples were analysed by X-ray tomography using synchrotron radiation. The three-dimensional images were used to observe the qualitative differences between the three samples. Three-dimensional image processing was then carried out to quantify the differences. The images were used to retrieve the fraction of the different phases which was in fairly good agreement with the expected values. The external and internal diameter of the spheres and their thickness were also measured. The MS1 spheres are smaller, thicker and their size distribution is less homogeneous compared to the MS2. The size distribution of the spheres before blowing was retrieved and evidenced to be similar for the two kinds of spheres. The thickness depends only weakly on the diameter of the spheres.

Study on the Formability and Friction of Hot Forging Process of a Spur Gear Shaft for Manufacturing Engineering

2012 ◽  
Vol 583 ◽  
pp. 251-254
Author(s):  
Guang Chun Wang ◽  
Bin Hai Hao ◽  
Fu Xiao Pei ◽  
Tao Wang
Keyword(s):  
Friction Coefficient ◽  
Initial Temperature ◽  
Hot Forging ◽  
Spur Gear ◽  
Billet Temperature ◽  
Forging Process ◽  
Initial Billet ◽  
Manufacturing Engineering ◽  
Hot Forging Process ◽  
Good Agreement

Hot forging processes of a spur gear shaft with three billet sizes are simulated using FEM. The billet with size of φ36*60 has the best formability in hot forging the spur gear shaft. The effects of the initial billet temperature and the friction coefficient on the hot forging formability of the spur gear shaft are obtained respectively through simulation. Hot forging experiments are carried out and experimental results show good agreement with those in simulation. At last, the reasonable hot forging parameters of the spur gear shaft for manufacturing engineering are suggested as follows: billet size of φ36*60, billet initial temperature of 1050°C and friction coefficient of 0.3.

Numerical Simulation of Premixed Hydrogen-Air Combustion Behavior in a Closed Vessel

2017 ◽  
Author(s):  
Youyou Xu ◽  
Min Li ◽  
Xiaojian Wen ◽  
Songlin Liu
Keyword(s):  
Numerical Simulation ◽  
Initial Temperature ◽  
Published Data ◽  
Internal Diameter ◽  
Stoichiometric Ratio ◽  
Closed Vessel ◽  
Effect Factors ◽  
Propagation Behavior ◽  
Temperature And Pressure ◽  
Design Pressure

A closed vessel of 1.9 m length and 0.9 m in internal diameter is being designed and will be constructed to experimentally investigate combustion and propagation behavior of the hydrogen-air mixture. Before the experiment is performed, the benchmark and pre-analyses on the hydrogen combustion and propagation behavior in this vessel are carried out by using FLUENT CFD code. The benchmark results indicated that the peak overpressure verse time agrees well with the experimental results of published data. Furthermore, the effect factors such as the hydrogen concentrations, the ignition position, the initial temperature and the pressure were simulated. The results show that the ignition position, initial temperature and pressure have significantly influence on hydrogen behavior. In addition, the overpressure increases with the equivalent ratio and reaches the peak in the vicinity of stoichiometric ratio. However, the overpressure peak is considerably lower than the design pressure of the vessel.

scholarly journals Sewage Sludge Bio-Oil Development and Characterization

Inventions ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 36
Author(s):  
Zeban Shah ◽  
Renato Cataluña Veses ◽  
Jonatan Brum ◽  
Marcos Antônio Klunk ◽  
Luiz Alberto Oliveira Rocha ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Physicochemical Properties ◽  
Initial Temperature ◽  
Proton Nuclear Magnetic Resonance ◽  
Pyrolysis Process ◽  
Fuel Conversion ◽  
Oil Development ◽  
Cooking Oil ◽  
Bio Oil ◽  
Good Agreement

This work presents the production of sewage sludge oil by pyrolysis, shows the physicochemical properties and compares it with commercial diesel. The sewage sludge was dried and mixed to discarded cooking oil to increase the fuel conversion rate due to the pyrolysis process at an initial temperature of 25 °C and a final of 650 °C. The oil was distilled and analyzed in a Proton nuclear magnetic resonance (1H-NMR), Gas Chromatogram and Mass spectrometry (GC-MS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) to perform a structural characterization on the molecular distribution, groups of functions and the product thermal stability. The authors measured fundamental physicochemical properties like viscosity, density and flashpoint and compared the results with the corresponding commercial S-10 diesel properties observing good agreement.

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