Shock tube

Abstract: Collisional Processes.- Analytical Formulae for Cross Sections and Rate Constants of Elementary Processes in Gases.- Relaxation of Velocity Distribution of Electrons Cooled (Heated) By Rotational Excitation (De-Excitation) Of N2.- Effects of the Initial Molecular States in a High-Energy Scattering of Molecular Beams.- Differential Cross Sections for Ion-Pair Formation with Selection of the Exit Channel.- Low-temperature Viscosity Cross Sections Measured in a Supersonic Argon Beam II.- Excited Oxygen Iodine Kinetic Studies.- Determination of Antisymmetric Mode Energy of CO2 Injected into a Supersonic Nitrogen Flow.- Molecular Beams.- Where are we going with molecular beams?.- Cesium Vapor Jettarget Produced With a Supersonic Nozzle.- Basic Features of the Generation and Diagnostics of Atomic Hydrogen Beams in the Ground and Metastable 22S1/2-States to Determine the Fundamental Physical Constants.- Optical Pumping Of Metastable Neon Atoms in A Weak Magnetic Field.- CO2-Laser Excitation of a Molecular Beam Monitored By Spontaneous Raman Effect.- Time-of-Flight and Electron Beam Fluorescence Diagnostics: Optimal Experimental Designs.- Molecular Beam Time-of-Flight Measurements in A Nearly Freejet Expansion of High Temperature Gas Produced By a Shock Tube.- Electron Beam Diagnostics.- Electron-Beam Diagnostics of High Temperature Rarefied Gas Flows.- Excitation Models Used in the Electron Beam Fluorescence Technique.- Electron - Beam Diagnostics in Nitrogen Multiquantum Rotational Transitions.- Free Jets, Nonequilibrium Expansions.- Free Jet as an Object of Nonequilibrium Processes Investigation.- State Dependent Angular Distributions of Na2 Molecules in a Na/Na2 Free Jet Expansion.- Molecular Beam Time-of-Flight Measurements and Moment Method Calculations of Translational Relaxation in Highly Heated Free Jets of Monatomic Gas Mixtures.- Rovibrational State Population Distributions of CO (v ? 4, J ? 10) In Highly Heated Supersonic Free Jets of CO-N2 Mixtures.- Free Jet Expansion with A Strong Condensation Effect.- Measured Densities in UF6 Free Jets.- Rotational Relaxation of NO in Seeded, Pulsed Nozzle Beams.- The Free-Jet Expansion from a Capillary Source.- Rotational Relaxation in High Temperature Jets of Nitrogen.- Translational Nonequilibrium in a Free Jet Expansion of a Binary Gas Mixture.- Laser Induced Fluorescence Study of Free Jet Expansions.- Jet-Surface Interactions.- Experimental Study of Plume Impingement and Heating Effect on Ariane's Payload.- The Interaction of a Jet Exhausting from a Body with a Supersonic Free Flow of a Rarefied Gas.- Modelling Control Thruster Plume Flow and Impingement.- Impingement of a Supersonic, Underexpanded Rarefied Jet upon a Flat Plate.- Some Peculiarities of Power and Heat Interaction of a Low Density Highly Underexpanded Jet with a Flat Plate.- Condensation in Flows.- Nonequilibrium Condensation in Free Jets.- Condensation and Vapour-Liquid Interaction in a Reflected Shock Region.- Homogeneous and Heterogeneous Condensation of Nitrogen in Transonic Flow.- Investigation of Nonequilibrium Homogeneous Gas Condensation.- The Peculiarities of Condensation Process in Conical Nozzle and in Free Jet Behind it.- Investigation of Nonequilibrium Argon Condensation In Supersonic Jet By Mass-Spectrometry, Electron Diffraction and VUV Emission Spectroscopy.- Clusters and Nucleation Kinetics.- The Microscopic Theory of Clustering and Nucleation.- Kinetics of Cluster Formation and Growth in the Process of Isothermal Condensation.- Relaxation Processes in a Molecular Dynamic Model of Cluster from the Lennard-Jones Particles.- Quantum-Chemical Study Of Processes With Cluster Isomerism.- The Homogeneous Nucleation at the Continuously Changing Temperature and Vapour Concentration.- Molecular Clusters as Heterogeneous Condensation Nuclei.- Experiments with Clusters.- The Photochemistry of Small van der Waals Molecules as Studied by Laser Spectroscopy in Supersonic Free Jets.- Diagnostics of Clusters in Molecular Beams.- Experimental Studies of Water-Aerosol Explosive Vaporization.- Laser Probing of Cluster Formation and Dissociation in Molecular Beams.- Free Molecule Drag on Helium Clusters.- Vibrational Relaxation Kinetics in a Two-Phase Gas-Cluster System.- Gas-Particle Flows.- Long-Range Attraction in the Collisions of Free-Molecular and Transition Regime Aerosol Particles.- Nonequilibrium Statistical Theory of Dispersed Systems.- The Mechanism of Strong Electric Field Effect on the Dispersed Media in the Rarefied Gas.- Generation of High-Speed Aerosol Beams By Laval Nozzles.- Kinetic Model of a Gas Suspension.- Gas Mixtures.- Kinetic Phenomena in the Rarefied Gas Mixtures Flowing Through Channels.- On the Discrete Boltzmann Equation for Binary Gas Mixtures.- Peculiarities and Applicability Conditions of Macroscopic Description of Disparate Molecular Masses Mixture Motion.- Numerical Solution of the Boltzmann Kinetic Equation for the Binary Gas Mixture.- Species Isotope Separation.- Gas or Isotope Separation by Injection into Light Gas Flow.- Molecular Diffusion Through a Fine-Pored Filter Versus Resonante IR-Radiation Intensity.- On Limiting Situations of Gas Dynamic Separation.- A Study of Reverse Leaks.- Investigation of Nonequilibrium Effects in Separation Nozzles by Monte-Carlo Simulation.- Separation of Binary Gas Mixtures at their Effusion through a Capillary and a Nuclear Filler into Vacuum.- Ionized Gases.- Effects of Nonideality in Quantum Kinetic Theory.- Molecular Mass and Heat Transfer of Chemical Equilibrium Multicomponent Partially Ionized Gases in Electromagnetic Field.- Spectroscopic Study of a Plasma Flow along the Stagnation Streamline of a Blunt Body.- On Model Kinetic Operators and Corresponding Langevin Sources for a Non-Equilibrium Plasma.- Related Fields.- Rarefied Gas Dynamics as Related to Controlled Thermonuclear Fusion.- Vacuum Ejectors with Appreciably Uneven Flows in Channels at Low Reynolds Numbers.- Simulation of the Process of the Cosmic Body Formation.

Abstract: A detailed chemical kinetic mechanism has been developed and used to study the oxidation of n-heptane in flow reactors, shock tubes, and rapid compression machines. Over the series of experiments numerically investigated, the initial pressure ranged from 1–42 atm, the temperature from 550–1700 K, the equivalence ratio from 0.3–1.5, and nitrogen-argon dilution from 70–99%. The combination of ignition delay time and species composition data provide for a stringent test of the chemical kinetic mechanism. The reactions are classed into various types, and the reaction rate constants are given together with an explanation of how the rate constants were obtained. Experimental results from the literature of ignition behind reflected shock waves and in a rapid compression machine were used to develop and validate the reaction mechanism at both low and high temperatures. Additionally, species composition data from a variable pressure flow reactor and a jet-stirred reactor were used to help complement and refine the low-temperature portions of the reaction mechanism. A sensitivity analysis was performed for each of the combustion environments. This analysis showed that the low-temperature chemistry is very sensitive to the formation of stable olefin species from hydroperoxy-alkyl radicals and to the chain-branching steps involving ketohydroperoxide molecules.

Abstract: The particle method SPH is applied to one-dimensional shock tube problems by incorporating an artificial viscosity into the equations of motion. When the artificial viscosity is either a bulk viscosity or the Von Neumann-Richtmyer viscosity, in a form analogous to that for finite differences, the results show either excessive oscillation or excessive smearing of the shock front. The reason for the excessive particle oscillation is that, in the standard form, the artificial viscosity cannot dampen irregular motion on the scale of the particle separation since that scale is usually less than the resolution of the interpolating kernel. We propose a new form of artificial viscosity which eliminates this problem. The resulting shock simulation has negligible oscillation and satisfactorily sharp discontinuities. Results with a gaussian interpolating kernel (with second-order errors) are shown to be greatly inferior to those with a super gaussian kernel (with fourth-order errors).

Abstract: A comprehensively tested H2/O2 chemical kinetic mechanism based on the work of Mueller et al. 1 and recently published kinetic and thermodynamic information is presented. The revised mechanism is validated against a wide range of experimental conditions, including those found in shock tubes, flow reactors, and laminar premixed flame. Excellent agreement of the model predictions with the experimental observations demonstrates that the mechanism is comprehensive and has good predictive capabilities for different experimental systems, including new results published subsequent to the work of Mueller et al. 1, particularly high-pressure laminar flame speed and shock tube ignition results. The reaction H + OH + M is found to be primarily significant only to laminar flame speed propagation predictions at high pressure. All experimental hydrogen flame speed observations can be adequately fit using any of the several transport coefficient estimates presently available in the literature for the hydrogen/oxygen system simply by adjusting the rate parameters for this reaction within their present uncertainties. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 566–575, 2004

Abstract: To determine self-ignition characteristics under conditions relevant to piston engines combustion, n-heptane-air mixtures have been investigated in a high-pressure shock tube without use of the customary heat bath dilution The initial pressure has been varied between 32 and 42 bar and the initial temperature between 660 and 1350 K, while the equivalence ratio covers the region between 05 and 30 In dependence upon these parameters the histories of pressure and CH-band emissions at 4315 A show different ignition behavior This can be related to different modes of ignition, as “strong” ignition and “weak” ignition and in part to two-stage-ignition The dependence of the ignition delay times upon initial temperature, pressure and equivalence ratio is presented A comparison with previous work is given