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The length scale criteria is widely accepted as an explanation for transition and hence existence of different shock wave
reflection configurations in pseudo-steady flows. However, there has not been any attempt to validate this criteria using
information obtained from a time-dependent numerical simulation. A high resolution time-dependent numerical simulation in
pseudo-steady flow is carried out in the present work. Time-dependent numerical data is used to calculate flow features in
a laboratory frame of reference to verify validity of the length scale criteria for existence of different shock wave reflection
configurations in pseudo-steady flow. This analysis is then extended to the study of unsteady shock wave reflection configurations
in shock–vortex interactions. It is shown that the existence of regular reflection (RR) and Mach reflection (MR) configurations
in an unsteady flowfield resulting from shock–vortex interactions can also be explained locally based on limiting conditions
similar to that prescribed by the length scale criteria for pseudo-steady flow.
相似文献
相似文献
84.
Khaled Al-Farhany Barik Al-Muhja Farhan Ali Umair Khan Aurang Zaib Zehba Raizah Ahmed M. Galal 《Molecules (Basel, Switzerland)》2022,27(14)
The proper process of applying heat to many technological devices is a significant challenge. There are many nanofluids of different sizes used inside the system. The current study combines this potential to improve convection effects, considering numerical simulations of natural convection using Cu/water nanofluids in a square enclosure with bottom blocks embedded in baffles. The enclosure consists of two vertical walls with isothermal boundary conditions; the left wall is the sinusoidal heat source, whereas the right wall is cooled. The investigations dealt with the influences of nanoparticle concentration, Rayleigh number, baffle length, and thermal conductivity ratioon isotherms, stream functions, and average Nusselt number. The results present that, when the Rayleigh number rises, the fluid flow velocity increases, and the heat transfer improves. Furthermore, the baffle length case (Lb = 0.3) provides higher heat transfer characteristics than other baffle height cases. 相似文献
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Lühl A Nayek HP Blechert S Roesky PW 《Chemical communications (Cambridge, England)》2011,47(29):8280-8282
The Zn-Zn bonded compound [(η(5)-Cp*)(2)Zn(2)] was investigated as catalyst for the inter- and intramolecular hydroamination reaction. High reaction rates under mild conditions were observed. This is the first application of a Zn-Zn bonded compound as catalyst. 相似文献
87.
Parimal Gaikwad A. Barik K. I. Priyadarsini B. S. M. Rao 《Research on Chemical Intermediates》2010,36(9):1065-1072
Studies on the antioxidant activity of two model phenols containing either an electron withdrawing (p-nitrophenol) or electron donating (p-aminophenol) group and p-hydroxyacetophenone in different solvents are reported using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay by spectrophotometry
and stopped-flow techniques. The second-order rate constants measured with p-nitrophenol were found to be (1.2–5.5) × 10−2 dm3 mol−1 s−1 but the DPPH radical reacts much faster with p-aminophenol (k = 0.5–1.1 × 104 dm3 mol−1 s−1). The normal kinetic solvent effect in H atom transfer was seen in the case of p-nitrophenol with the solvent independent rate constant k
o = 0.1 dm3 mol−1 s−1. The IC50 values in p-nitrophenol are similar to those measured in p-hydroxyacetophenone. On the other hand, much lower IC50 values of more than four orders of magnitude with p-aminophenol were observed. This work demonstrates that the phenol with the electron donating –NH2 substituent is a better antioxidant. 相似文献
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