摘要:

Two‐dimensional maps of the heavy particle and electron densities are produced for ionized supersonic corner expansions of argon and neon. The experimental results are compared with theoretical models that account for recombination processes in the expansion fan.

ISSN:0094-243X    

DOI:10.1063/1.39366

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The paper is concerned with the results of experimental investigation of a discharge in supersonic flows of a CO2:N2:He mixture. Simultaneous measurements are made of current and discharge voltage in a medium as well as of the gain coefficient of a small signal both due to gasdynamic ‘‘freezing’’ and due to electric preexcitation. Results are presented on measuring the initial electron density in supersonic gas flows of vibrational excited molecules.

ISSN:0094-243X    

DOI:10.1063/1.39367

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Explicit numerical algorithms that solve the axisymmetric unsteady Euler equations have been used to study the shock wave discharge from a shock tube into a disc shaped MHD channel, and the subsequent interaction of the flowing plasma with the magnetic field. Comparisons among the algorithms varying with respect to the differencing, order and type are discussed.

ISSN:0094-243X    

DOI:10.1063/1.39368

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

It is shown that the second viscosity method is universal for the gasdinamic disturbances evolution description in the partially ionised plasma. It is considered the nonlinear acoustic structures.

ISSN:0094-243X    

DOI:10.1063/1.39369

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

It’s considered some effects of the gas‐plasma interaction that is discharge damping behind the shock wave front, the structure of the weak shock wave (SW) front in plasma and SW generation by the breakdown wave front.

ISSN:0094-243X    

DOI:10.1063/1.39370

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Values of the rate constant for the reaction O(3P)+NH3were determined by compring calculated O atom profiles with those obtained experimentally in the temperature range 2069‐2459K. Oxygen atoms were generated by thermal decomposition of N2O. The results were combined with those from previous direct studies (448‐1790K) to given the following expression 448‐2459K:       k2(T)=2.27×10−18 T2.19exp(−3061/T) cm3molecule−1s−1  An overall uncertainty of ±25% is estimated for this expression.

ISSN:0094-243X    

DOI:10.1063/1.39372

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The reaction of CH3with O2has been studied in shock tube experiments over the temperature and total pressure of 1050‐1550 K and 0.3‐0.7 atm, respectively. CO and H2O concentration‐time profiles were monitored simultaneously with two CW CO lasers. The computer modeling of our CO and H2O profiles yielded k1=1.28E13×exp(−28.0 kcal/RT), cm3mol−1s−1for reaction (1) CH3+O2→CH3O+O. The reaction channel (2) CH3+O2→CH2O+OH was found to be a minor. A detailed mechanism of CH3+O2is proposed. The sensitivity analysis shows k2has low sensitivity to H2O and CO concentration profiles.

ISSN:0094-243X    

DOI:10.1063/1.39373

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Kinetic studies of the H+O2→O+OH reaction using two independent absorption spectroscopies behind shock waves are reported. Time histories of O atom concentration were measured using atomic resonant absorption spectroscopy at 130 nm in incident‐shock‐heated H2‐O2mixtures in the temperature range 1600–2700 K at pressures of about 1 atm. OH concentration profiles were measured using a narrow band frequency‐doubled cw dye laser at 310 nm in reflected‐shock‐heated H2‐O2mixtures in the temperature range from 1900 to 2600 K at pressure between 1.5 and 3 atm. Both experiments were performed in rich H2‐O2mixtures highly dilute in Ar.By combining those data obtained from the both absorption spectroscopic measurements with reported values obtained previously at low temperature, the following expression, k=107.0T2.0 exp(−43 kJ/RT) cm3.mol−1.s−1, for H+O2→O+OH was determined in the temperature ranges between 1100 and 2700 K.

ISSN:0094-243X    

DOI:10.1063/1.39374

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Experimental and modelling studies on the ignition characteristics of benzene are presented for a wide range of initial conditions. An empirical correlation is proposed for the induction times which show good agreement with the values reported in literature. A comprehensive chemical kinetic reaction mechanism consisting of 70 reactions among 30 species is adopted for computing species concentrations and this is found to be adequate to describe the delay data reported in this paper. The predicted species profiles are found to match qualitatively a few experimental profiles published in literature. The relative contribution of each reaction for the formation/consumption of each species, for a specific reaction time, is determined by a detailed sensitivity analysis.

ISSN:0094-243X    

DOI:10.1063/1.39375

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The reflected shock wave technique was used to study soot formation in highly argon‐diluted methane‐oxygen mixtures. The experiments were performed at temperatures ranging from 1700 K to 2000 K and high pressures (3000–9000kN/m2) behind the reflected shock. Soot particles were detected and measured by the optical dispersion quotient method. Particle sizes up to 0.25 &mgr;m and particle concentrations up to 1010particles/cm3could be measured. The typical characteristics of soot formation and its dependence on temperature as found at lower pressures is shown. Soot formation proved to have a maximum at temperatures of approximately 1850Kand to increase almost linearly with pressure. Soot induction times were measured by monitoring the attenuation of a He‐Ne laser beam.

ISSN:0094-243X    

DOI:10.1063/1.39376

出版商:AIP    

年代:1990

数据来源: AIP