Dependence of Vibrational Relaxation Time on the Vibrational Quantum Number. Experimental Verification for NO (A 2Σ+) behind Shock Waves

1961 ◽  
Vol 34 (6) ◽  
pp. 2204-2205 ◽  
Author(s):  
Walter Roth
Keyword(s):  
Relaxation Time ◽  
Shock Waves ◽  
Quantum Number ◽  
Experimental Verification ◽  
Vibrational Relaxation ◽  
Vibrational Quantum Number

Temperature measurements of shock waves and detonations by spectrum-line reversal III. Observations with chromium lines

1961 ◽  
Vol 262 (1308) ◽  
pp. 38-50 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Relaxation Time ◽  
Shock Waves ◽  
Vibrational Relaxation ◽  
Weak Shock ◽  
Temperature Measurements ◽  
Excitation Temperature ◽  
Satisfactory Explanation ◽  
Excitation Processes ◽  
Very High

Temperature measurements have been made with the chromium resonance triplet at 4254, 4274 and 4289 Å, controlled amounts of chromium being introduced in the form of the volatile carbonyl; this method has the advantage that it can be used with explosive mixtures. Measurements of vibrational relaxation time have been made for carbon monoxide between 2200 and 2700°K and of the rate of dissociation of hydrogen in hydrogen + argon mixtures between 2400 and 2800°K. Temperature irregularities in the fronts of shocks through argon or neon are discussed, but no satisfactory explanation for them has been found. Excitation processes in monatomic gases are also examined. The method has been used to study the temperature distribution behind detonations which have been initiated by shocks of various strengths. For ethylene + oxygen detonations the chromium excitation temperature is very high at the front; this is attributed to chemiluminescent excitation in the reaction zone. In carbon monoxide + oxygen detonations initiated by weak shock waves we have observed interesting steps in the temperature behind the front and have explained these as being due to delayed ignition behind the shock and an acceleration of the front leading to detonation after the front has travelled some way along the shock tube.

Normal interaction of shock waves in the presence of vibrational relaxation

1977 ◽  
Vol 11 (4) ◽  
pp. 565-570
Author(s):  
V. T. Kireev ◽  
N. A. Tikhomirov
Keyword(s):  
Shock Waves ◽  
Vibrational Relaxation ◽  
Interaction Of Shock Waves

The D and D′ states of the PO molecule

1968 ◽  
Vol 46 (18) ◽  
pp. 2079-2086 ◽  
Author(s):  
R. D. Verma ◽  
M. N. Dixit
Keyword(s):  
Quantum Number ◽  
Isotopic Shift ◽  
Rotational Analysis ◽  
Vibrational Quantum Number

A rotational analysis of the 0–0, 0–1, and 0–2 bands of the D–B and D′–B systems of PO in the region 5500–6900 Å has been carried out from a spectrum obtained at a resolution higher than that of previous workers (Couet and Guenebaut 1966; Couet et al. 1967). The mutual perturbation between D2Πr and D′2Πr has been confirmed from the rotational analysis of the 0–0 and 0–1 bands of the D–A and D′–X systems in the region 2000–2200 Å. The analysis of the D′–X bands has shown that the previously reported E′ state lying between the D and D′ states is actually part of the D′ state. The constants of the D2Πr, D′ 2Πr, B2Σ+, and X2Π states are evaluated and compared with the constants of earlier workers to remove the inconsistency existing in their values for the B and X states.The isotopic bands corresponding to P18O of the D–B and D′–B systems are obtained, thus showing that the D′ state has an anomalous isotopic shift and that the observed levels of the D and D′ states have the vibrational quantum number ν =.

On the breakdown of characteristics solutions in flows with vibrational relaxation

1967 ◽  
Vol 27 (1) ◽  
pp. 49-57 ◽  
Author(s):  
B. S. H. Rarity
Keyword(s):  
Relaxation Time ◽  
Mach Number ◽  
Supersonic Flow ◽  
Steady Flow ◽  
Speed Of Sound ◽  
Vibrational Relaxation ◽  
Precise Measure ◽  
Derivatives Of ◽  
Relaxing Gas ◽  
Flow Case

The breakdown of the characteristics solution in the neighbourhood of the leading frozen characteristic is investigated for the flow induced by a piston advancing with finite acceleration into a relaxing gas and for the steady supersonic flow of a relaxing gas into a smooth compressive corner. It is found that the point of breakdown moves outwards along the leading characteristic as the relaxation time decreases and that there is no breakdown of the solution on the leading characteristic if the gas has a sufficiently small, but non-zero, relaxation time. A precise measure of this relaxation time is derived. The paper deals only with points of breakdown determined by initial derivatives of the piston path or wall shape. In the steady-flow case, the Mach number based on the frozen speed of sound must be greater than unity.

Sign in / Sign up

Export Citation Format

Share Document