Tabular and Grapical Solutions of Regular and Mach Reflections in Pseudo-Stationary Frozen and Vibrational-Equilibrium Flows. Part 2.

1985 ◽  
Author(s):  
T. C. J. Hu ◽  
M. Shirouzu
Keyword(s):  
Vibrational Equilibrium

Two-Dimensional Infrared Spectroscopy From the Gas to Liquid Phase: Density Dependent J-Scrambling, Vibrational Relaxation, and the Onset of Liquid Character

2019 ◽  
Author(s):  
Greg Ng Pack ◽  
Matthew Rotondaro ◽  
Parth Shah ◽  
Aritra Mandal ◽  
Shyamsunder Erramilli ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Rotational Relaxation ◽  
Vibrational Energy Relaxation ◽  
Pump Probe ◽  
Solution Dynamics ◽  
Supercritical Phase ◽  
Supercritical Solution ◽  
Asymmetric Stretch ◽  
Two Dimensional Infrared Spectroscopy ◽  
Vibrational Equilibrium

Ultrafast 2DIR spectra and pump-probe responses of the N2O n 3 asymmetric stretch in SF6 as a function of density from the gas to supercritical phase and liquid are reported. 2DIR spectra unequivocally reveal free rotor character at all densities studied in the gas and supercritical region. Analysis of the 2DIR spectra determines that J-scrambling or rotational relaxation in N2O is highly efficient, occurring in ~1.5 to ~2 collisions with SF6 at all non-liquid densities. In contrast, N2O n 3 vibrational energy relaxation requires ~15 collisions, and complete vibrational equilibrium occurs on the ~ns scale at all densities. An independent binary collision model is sufficient to describe these supercritical state point dynamics. The N2O n 3 in liquid SF6 2DIR spectrum shows no evidence of free rotor character or spectral diffusion. Using these 2DIR results, hindered rotor or liquid-like character is found in gas and all supercritical solutions for SF6 densities ³ r * = 0.3, and increases with SF6 density. 2DIR spectral analysis offers direct time domain evidence of critical slowing for SF6 solutions closest to the critical point density. Applications of 2DIR to other high density and supercritical solution dynamics and descriptions are discussed. <br>

scholarly journals Dependence of Calculated Postshock Thermodynamic Variables on Vibrational Equilibrium and Input Uncertainty

2017 ◽  
Vol 31 (3) ◽  
pp. 586-608 ◽  
Author(s):  
Matthew F. Campbell ◽  
Kyle G. Owen ◽  
David F. Davidson ◽  
Ronald K. Hanson
Keyword(s):  
Input Uncertainty ◽  
Thermodynamic Variables ◽  
Vibrational Equilibrium

Concentration and Temperature Dependence of Laurdan Fluorescence in Glycerol

2003 ◽  
Vol 58 (9-10) ◽  
pp. 581-588 ◽  
Author(s):  
K. A. Kozyra ◽  
J. R. Heldt ◽  
J. Heldt ◽  
M. Engelkec ◽  
H. A. Diehl
Keyword(s):  
Steady State ◽  
Time Distribution ◽  
Emission Spectra ◽  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Fluorescence Decay Time ◽  
Laurdan Fluorescence ◽  
Vibrational Equilibrium

Steady-state and time-resolved fluorescence measurements have been performed on Laurdan, dissolved in viscous glycerol, as functions of temperature and concentration. The results indicate spectral heterogeneity of the Laurdan solution. The fluorescence decay time distribution is attributed to radiative deexcitation of spatial conformational forms of locally excited (LE) and charge transfer (CT) states, the S1(CT)EQ state being in thermodynamic and vibrational equilibrium. The lifetimes and contributions of the different fluorescence modes depend on concentration and temperature. The excitation and emission spectra show discontinuous changes with increase of the Laurdan concentration.We suppose that the observed changes are caused by the formation of Laurdan micelle aggregates.

Nonlinear Vibrations of an Extensible Flexible Marine Riser Carrying a Pulsatile Flow

2006 ◽  
Vol 74 (4) ◽  
pp. 754-769 ◽  
Author(s):  
T. Monprapussorn ◽  
C. Athisakul ◽  
S. Chucheepsakul
Keyword(s):  
Pulsatile Flow ◽  
Nonlinear Vibrations ◽  
Numerical Solutions ◽  
Large Strain ◽  
Internal Flow ◽  
Marine Riser ◽  
Riser Pipe ◽  
Flexible Pipes ◽  
High Degree ◽  
Vibrational Equilibrium

The influence of transported fluid on static and dynamic behaviors of marine risers is investigated. The internal flow of the transported fluid could have a constant, a linear, or a wave velocity. The riser pipe may possibly experience the conditions of high extensibility, flexibility, and large displacements. Accordingly, the mathematical riser models should be governed by the large strain formulations of extensible flexible pipes transporting fluid. Nonlinear hydrodynamic dampings due to ocean wave–pipe interactions implicate the high degree of nonlinearity in the riser vibrations, for which numerical solutions are determined by the state–space–finite-element method. It is revealed that the impulsive acceleration of internal flow could seriously relocate the vibrational equilibrium positions of the riser pipe. The fluctuation of the pulsatile flow relatively introduces the expansion of amplitudes and the reduction of frequencies of the riser vibrations. The pulsatile frequencies of the internal flow in wave aspect could reform the oscillation behavior of the conveyor pipe.

Pseudostationary oblique shock-wave reflections in sulphur hexafluoride (SF 6 ): interferometric and numerical results

1986 ◽  
Vol 408 (1835) ◽  
pp. 321-344 ◽  
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Triple Point ◽  
Wave Reflection ◽  
Incident Shock ◽  
Oblique Shock Wave ◽  
Wave Reflections ◽  
Shock Wave Reflection ◽  
Wedge Surface ◽  
Vibrational Equilibrium

Pseudostationary oblique shock-wave reflections in SF 6 were investigated experimentally and numerically. Experiments were concluded in the UTIAS 10 x 18 cm Hypervelocity Shock Tube in the range of incident shock wave Mach number 1.25 < M s < 8.0 and wedge angle 4° < θ w < 47° with initial pressure 4 < P 0 < 267 Torr (0.53-35.60 kPa) at temperatures T 0 near 300 K. The four major types of shock-wave reflection, i. e. regular reflection (RR), single-Mach (SMR), complex-Mach (CMR) and double-Mach reflections (DMR), were observed. These were studied by using infinite-fringe interferograms from a Mach-Zehnder interferometer with a 23 cm diameter field of view. The isopycnics and the density distributions along the wedge surface are presented for the various types of reflection. The analytical transition boundaries between the four types of shock-wave reflection were established up to M s = 10.0 for frozen and equilibrium vibrational SF 6 . An examination of the relaxation length under the present experimental conditions indicated that a vibrational-equilibrium analysis was required. Comparisons of experiment with analysis for transition-boundary maps, reflection angle δ and the first triple-point trajectory angle X verify that the reflections were in vibrational equilibrium. The excellent agreement between the present interferometric results and the numerical results obtained by H. M. Glaz et al . ( Proc. int. colloq. on dynamics of explosives and reactive systems [ Berkeley ] (1985)) with real-gas effects also supports the vibrational equilibrium hypothesis for shocked SF 6 . The behaviour of the angle between the two triple-point trajectories ( X ' — X ) is discussed and the unique pattern of DMR with X ' = 0 was verified experimentally. A numerical analysis for the second triple-point system is obtained for the first time. It is shown that, for a given incident shock Mach number, the highest wedge-surface pressure is achieved through a DMR instead of an RR at high M s .

Two-Dimensional Infrared Spectroscopy From the Gas to Liquid Phase: Density Dependent J-Scrambling, Vibrational Relaxation, and the Onset of Liquid Character

2019 ◽  
Author(s):  
Greg Ng Pack ◽  
Matthew Rotondaro ◽  
Parth Shah ◽  
Aritra Mandal ◽  
Shyamsunder Erramilli ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Rotational Relaxation ◽  
Vibrational Energy Relaxation ◽  
Pump Probe ◽  
Solution Dynamics ◽  
Supercritical Phase ◽  
Supercritical Solution ◽  
Asymmetric Stretch ◽  
Two Dimensional Infrared Spectroscopy ◽  
Vibrational Equilibrium

Ultrafast 2DIR spectra and pump-probe responses of the N2O n 3 asymmetric stretch in SF6 as a function of density from the gas to supercritical phase and liquid are reported. 2DIR spectra unequivocally reveal free rotor character at all densities studied in the gas and supercritical region. Analysis of the 2DIR spectra determines that J-scrambling or rotational relaxation in N2O is highly efficient, occurring in ~1.5 to ~2 collisions with SF6 at all non-liquid densities. In contrast, N2O n 3 vibrational energy relaxation requires ~15 collisions, and complete vibrational equilibrium occurs on the ~ns scale at all densities. An independent binary collision model is sufficient to describe these supercritical state point dynamics. The N2O n 3 in liquid SF6 2DIR spectrum shows no evidence of free rotor character or spectral diffusion. Using these 2DIR results, hindered rotor or liquid-like character is found in gas and all supercritical solutions for SF6 densities ³ r * = 0.3, and increases with SF6 density. 2DIR spectral analysis offers direct time domain evidence of critical slowing for SF6 solutions closest to the critical point density. Applications of 2DIR to other high density and supercritical solution dynamics and descriptions are discussed. <br>

Sign in / Sign up

Export Citation Format

Share Document