Author: Howard Wong
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 156
Book Description
Preliminary Study of the Rate and Degree of Thermal Ionization of Argon Behind Shock Waves
Author: Howard Wong
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 156
Book Description
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 156
Book Description
Thermal Ionization Behind Strong Shock Waves in Argon
Author: Dennis Martin Phillips
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
Approach to Equilibrium Ionization Behind Strong Shock Waves in Argon
Author: Harry Petschek
Publisher:
ISBN:
Category :
Languages : en
Pages : 72
Book Description
Previous work on strong shock waves in argon has shown that the degree of ionization reaches thermodynamic equilibrium for shock speeds greater than about ten times the speed of sound in room temperature argon. The degree of ionization reaches about 25% at the highest shock strengths available in an ordinary shock tube. This paper reports a detailed theoretical and experimental study of the approach of high temperature argon to this equilibrium degree of ionization. The mechanism for the approach to equilibrium can be divided into two stages. The first, which accounts for about 10% of the final ionization, is apparently controlled by impurities present in the gas even after considerable care is taken to insure high purity. In the second stage ionization by electron-atom collisions becomes dominant. The rate of ionization by this process is limited by the rate of energy transfer to electrons by elastic collisions with the atoms and ions in the gas and is relatively independent of the inelastic ionization crosssection. This rate is calculated and is in agreement with experimental measurements making use of (1) the visible continuum radiation from the gas, and (2) the electrostatic potentials in the gas due to the diffusion of electrons. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 72
Book Description
Previous work on strong shock waves in argon has shown that the degree of ionization reaches thermodynamic equilibrium for shock speeds greater than about ten times the speed of sound in room temperature argon. The degree of ionization reaches about 25% at the highest shock strengths available in an ordinary shock tube. This paper reports a detailed theoretical and experimental study of the approach of high temperature argon to this equilibrium degree of ionization. The mechanism for the approach to equilibrium can be divided into two stages. The first, which accounts for about 10% of the final ionization, is apparently controlled by impurities present in the gas even after considerable care is taken to insure high purity. In the second stage ionization by electron-atom collisions becomes dominant. The rate of ionization by this process is limited by the rate of energy transfer to electrons by elastic collisions with the atoms and ions in the gas and is relatively independent of the inelastic ionization crosssection. This rate is calculated and is in agreement with experimental measurements making use of (1) the visible continuum radiation from the gas, and (2) the electrostatic potentials in the gas due to the diffusion of electrons. (Author).
First Award Papers
Author: Institute of the Aeronautical Sciences (U.S.)
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 260
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 260
Book Description
Preliminary Temperature Measurements Behind Strong Shock Waves in Argon
Author: A. Levy
Publisher: Institute for Aerospace Studies, University of Toronto
ISBN:
Category : Argon
Languages : en
Pages : 23
Book Description
The need for temperature measurement in strong shock waves is discussed briefly and requirements for a suitable experimental method are established. Spectrometric methods are shown to be appropriate and the radiative line intensity technique is discussed. Experiments using photography for both time-integrated and time-resolved exploration of the argon emission spectrum in a M sub s = 11.3, p sub 1 = 3 torr shock are described. The results were used in the main series of experiments, which gave time-resolved records from photo-multipliers monitoring the intensities of selected neutral argon lines. These records are analyzed, including self-absorption correction, to a time-resolved excitation temperature profile for the neutral argon atoms. The probable uncertainty in these measurements is computed and the shape of the temperature profile is discussed. The conclusions are that the atom excitation temperature rises to an approximately constant value of about 11,500K behind the shock front, which is in fair agreement with the calculated equilibrium value of 11,300K, but that uncertainties were too great to allow, for example, cooling calculations based on the shape of the temperature profile. Experimental improvements are suggested to reduce uncertainties and allow detailed analyses in future work. (Author).
Publisher: Institute for Aerospace Studies, University of Toronto
ISBN:
Category : Argon
Languages : en
Pages : 23
Book Description
The need for temperature measurement in strong shock waves is discussed briefly and requirements for a suitable experimental method are established. Spectrometric methods are shown to be appropriate and the radiative line intensity technique is discussed. Experiments using photography for both time-integrated and time-resolved exploration of the argon emission spectrum in a M sub s = 11.3, p sub 1 = 3 torr shock are described. The results were used in the main series of experiments, which gave time-resolved records from photo-multipliers monitoring the intensities of selected neutral argon lines. These records are analyzed, including self-absorption correction, to a time-resolved excitation temperature profile for the neutral argon atoms. The probable uncertainty in these measurements is computed and the shape of the temperature profile is discussed. The conclusions are that the atom excitation temperature rises to an approximately constant value of about 11,500K behind the shock front, which is in fair agreement with the calculated equilibrium value of 11,300K, but that uncertainties were too great to allow, for example, cooling calculations based on the shape of the temperature profile. Experimental improvements are suggested to reduce uncertainties and allow detailed analyses in future work. (Author).
First Award Papers, IAS Regional Student Conferences
Author: Institute of the Aerospace Sciences
Publisher:
ISBN:
Category :
Languages : en
Pages : 802
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 802
Book Description
A Unified Treatment of the Relaxation Phenomenon in Radiating Argon Plasma Flows Behind Incident and Bow Shock Waves
Author: Peter E. Oettinger
Publisher:
ISBN:
Category : Argon
Languages : en
Pages : 168
Book Description
Publisher:
ISBN:
Category : Argon
Languages : en
Pages : 168
Book Description
Experimental Study on the Ionization of Argon Gas in a Non-Equilibrium State Behind Reflected Shock Waves
Author: K. Terao
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
The electron temperature, the density and the ion temperature in argon gas behind reflected shock waves were measured by a laser light scattering method, while the gas temperature was measured by the spectroscopic method. The values of these three temperatures are different from each other during a certain period after arrival of the reflected shock front. Both the electron and ion temperatures are much higher than the theoretical gasdynamic temperature. The ionization rate is also much higher than that in the equilibrium state, but the measured gas temperature is lower than the theoretical one. These results suggest that the argon gas is in a non-equilibrium state during the first period.
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
The electron temperature, the density and the ion temperature in argon gas behind reflected shock waves were measured by a laser light scattering method, while the gas temperature was measured by the spectroscopic method. The values of these three temperatures are different from each other during a certain period after arrival of the reflected shock front. Both the electron and ion temperatures are much higher than the theoretical gasdynamic temperature. The ionization rate is also much higher than that in the equilibrium state, but the measured gas temperature is lower than the theoretical one. These results suggest that the argon gas is in a non-equilibrium state during the first period.
Evaluation of Shock-tube Heat-transfer Experiments to Measure Thermal Conductivity of Argon from 700 ̊to 8600 ̊K
Author: Milton R. Lauver
Publisher:
ISBN:
Category : Argon
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Argon
Languages : en
Pages : 32
Book Description