Author: Jagnandan Kumar BhanguPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Shock Tube Studies of Vibrational Relaxation in Nitrous Oxide
Author: Jagnandan Kumar BhanguA Shock Tube Study of Vibrational Relaxation in Nitrous Oxide
Author: C.J.S.M. SimpsonA Shock Tube Study of the Vibrational Relaxation of Nitric Oxide
Author: KURT L. WRAYPublisher:
ISBN:
Category :
Languages : en
Pages : 1
Book Description
The vibrational relaxation time of nitric oxide in NO-Ar mixtures was determined over the temperature range 1500-7000 K. An ultraviolet absorption technique using 1270 A radiation was employed to monitor the vibrational temperature as a function of time after these mixtures were shock heated to high translational temperatures. P10, the transition probability per oscillator per collision for transition between vibrational levels 1 and 0 calculated from the measured relaxation times ranged from 0.001 at 1500 K to 0.028 at 7000 K for NO-NO collisions. Argon is about 1/50 as efficient as NO. The results are compared with the lower temperature (400-1500 K) work of Robben and with the adiabatic theory of Schwartz, Slawsky, and Herzfeld and the nonadiabatic theory of Nikitin. (Author).
Shock Tube Studies of Nitrogen Vibrational Relaxation and Methane Oxidation
Author: Donald R. WhitePublisher:
ISBN:
Category :
Languages : en
Pages : 62
Book Description
The report summarizes the research performed under this contract in the general areas of vibrational relaxation and shock tube chemistry. The authors have unsuccessfully attempted to generate cylindrical detonations in H2-O2 under conditions such that the reaction zone and shock front could be observed first to separate and hopefully then to reattach. The induction time for methane has been measured over a wide range of pressure, temperature, stoichiometry, and diluent using both incident and reflected shock waves. An activation energy of about 51 kcal/mole is found, larger than that of several other investigators largely due to our observation of longer times at the lower temperatures. In the H2/CO/O2 system the combination of flame and interferometric shock data has earlier proved valuable in selection from among alternative kinetic schemes, but laminar reaction zones have been unattainable in methane oxidation without use of an additive to speed the reaction. Qualitatively, acetone, methyl alcohol, and acetylene all accelerate the reaction to a decreasing extent. Hydrogen has been used as an additive to obtain density profiles adequate for comparison with computed profiles using a complex reaction scheme. A first attempt at computer reconciliation of flame and shock tube data has been made with encouraging results, and changes to be incorporated in the next iteration of the kinetic system have been identified. (Author).
A Shock Tube Study of the Kinetics of Nitric Oxide at High Temperatures
Author: Kurt L. WrayPublisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 41
Book Description
A shock tube program was carried out in which the NO concentration was followed as a function of time behind the shock front by absorption of 1270A radiation, where ground vibrational state O2 and N2 are essentially transparent. The absorption coefficients of the species NO, O2 and N2 as functions of the respective vibrational temperatures were determined by measuring theABSORPTION BY THE SHOCK-HEATED GAS AT A POINT IN THE TIME HISTORY CORRESPONDING TO COMPLETE VIBRATIONAL RELAXATION BUT BEFORE THE ONSET OF DISSOCIATION. Time history analyses were made on a total of 42 shock tube runs covering a temperature range of 3000-8000 K on the following six mixtures: 1/2% NO, 1/2% NO + 1/4% O2, 10% NO, 50% NO, 20% air and 100% air. The diluent in all cases was argon. An IBM 704 computer was programmed to integrate the vibrational and chemical rate equations as a function of time behind the shock front, subject to the constraints of the conservation equations. The pertinent rate constants were varied in a systematic trial and error manner in order to get the best fit to all the data. (Author).
Relaxation in Shock Waves
Author: Y.V. StupochenkoPublisher: Springer Science & Business Media
ISBN: 3642482465
Category : Technology & Engineering
Languages : en
Pages : 404
Book Description
Kinetics of Nitric Oxide Formation Behind 3 to 4 KM/S Shock Waves
Author: Charles E. TreanorPublisher:
ISBN:
Category :
Languages : en
Pages : 52
Book Description
A previously published group of 02/N2 shock-tube experiments, wherein the time history of the NO 5 micrometers radiation was measured, has been studied to elicit information about the relevant chemical reactions which produce the radiation. It was found that the calculated radiation was sensitive to the rates used in the Zeldovich mechanism for NO formation, and that the rate measured by Monat et al. for N2 + 0 -- greater than NO + N produced important features of the observed radiation. Vibration-dissociation coupling in this reaction modifies the radiation history in an important way, and is an essential element in obtaining agreement with the experiment. To improve agreement over a range of 02/N2 mixtures, it was necessary to take into account the faster vibrational relaxation of N2 by 02 and 0 collisions and the subsequent effect on vibration-dissociation coupling ... Reaction rates, Vibration-dissociation coupling, Air chemistry, Nitric oxide radiation, Nitric oxide formation.
A Shock Tube Study of Molecular Vibrational Relaxation Rates Behind a Gas Dynamic Expansion
Author: Joseph Alan StregackPublisher:
ISBN:
Category : Carbon dioxide
Languages : en
Pages : 188
Book Description
Chemical Kinetics of Nitrous Oxide Decomposition at Elevated Pressures and Temperatures
Author: E. Stokes FishburnePublisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 31
Book Description
Kinetic studies of the thermal decomposition of nitrous oxide were conducte in the temperature range from 1000 to 2500 . the decomposition of nitrous oxide behind t e reflected shock wave in a shock tube wa investigated using photographic techniques. It appears that the rate of decomposition may be governed by the vibrational relaxation time of the lower energy valence b nd. Induction times for the rapid decompo ition of nitrous oxide range from 152 microseconds at 1430 K to zero microseconds at abo t 2500 K. The value of about 150 microseconds at 1430 K agrees qualitatively with approximate val e obtained by other investigators. (Author).
Author: R. Gutteridge