Realistic Weather Modeling for Hypersonic Vehicles: Raindrop Shock Interactions

2021 ◽  
Author(s):  
Hassan Beydoun ◽  
Andy Cook ◽  
Joseph Bauer ◽  
Elizabeth V. Stein
AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 2268-2276
Author(s):  
M. J. Wright ◽  
K. Sinha ◽  
J. Olejniczak ◽  
G. V. Candler ◽  
T. D. Magruder ◽  
...  

Shock Waves ◽  
2021 ◽  
Author(s):  
C. Garbacz ◽  
W. T. Maier ◽  
J. B. Scoggins ◽  
T. D. Economon ◽  
T. Magin ◽  
...  

AbstractThe present study aims at providing insights into shock wave interference patterns in gas flows when a mixture different than air is considered. High-energy non-equilibrium flows of air and $$\hbox {CO}_2$$ CO 2 –$$\hbox {N}_2$$ N 2 over a double-wedge geometry are studied numerically. The impact of freestream temperature on the non-equilibrium shock interaction patterns is investigated by simulating two different sets of freestream conditions. To this purpose, the SU2 solver has been extended to account for the conservation of chemical species as well as multiple energies and coupled to the Mutation++ library (Multicomponent Thermodynamic And Transport properties for IONized gases in C++) that provides all the necessary thermochemical properties of the mixture and chemical species. An analysis of the shock interference patterns is presented with respect to the existing taxonomy of interactions. A comparison between calorically perfect ideal gas and non-equilibrium simulations confirms that non-equilibrium effects greatly influence the shock interaction patterns. When thermochemical relaxation is considered, a type VI interaction is obtained for the $$\hbox {CO}_2$$ CO 2 -dominated flow, for both freestream temperatures of 300 K and 1000 K; for air, a type V six-shock interaction and a type VI interaction are obtained, respectively. We conclude that the increase in freestream temperature has a large impact on the shock interaction pattern of the air flow, whereas for the $$\hbox {CO}_2$$ CO 2 –$$\hbox {N}_2$$ N 2 flow the pattern does not change.


Author(s):  
Huilin Lun ◽  
Yi Zeng ◽  
Xiang Xiong ◽  
Ziming Ye ◽  
Zhongwei Zhang ◽  
...  

AbstractMulti-component solid solutions with non-stoichiometric compositions are characteristics of ultra-high temperature carbides as promising materials for hypersonic vehicles. However, for group IV transition-metal carbides, the oxidation behavior of multi-component non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution has not been clarified yet. The present work fabricated four kinds of (Zr,Hf,Ti)Cx carbide solid solution powders by free-pressureless spark plasma sintering to investigate the oxidation behavior of (Zr,Hf,Ti)Cx in air. The effects of metallic atom composition on oxidation resistance were examined. The results indicate that the oxidation kinetics of (Zr,Hf,Ti)Cx are composition dependent. A high Hf content in (Zr,Hf,Ti)Cx was beneficial to form an amorphous Zr-Hf-Ti-C-O oxycarbide layer as an oxygen barrier to enhance the initial oxidation resistance. Meanwhile, an equiatomic ratio of metallic atoms reduced the growth rate of (Zr,Hf,Ti)O2 oxide, increasing its phase stability at high temperatures, which improved the oxidation activation energy of (Zr, Hf, Ti)Cx.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eduardo Rossi ◽  
Gholamhossein Bagheri ◽  
Frances Beckett ◽  
Costanza Bonadonna

AbstractA large amount of volcanic ash produced during explosive volcanic eruptions has been found to sediment as aggregates of various types that typically reduce the associated residence time in the atmosphere (i.e., premature sedimentation). Nonetheless, speculations exist in the literature that aggregation has the potential to also delay particle sedimentation (rafting effect) even though it has been considered unlikely so far. Here, we present the first theoretical description of rafting that demonstrates how delayed sedimentation may not only occur but is probably more common than previously thought. The fate of volcanic ash is here quantified for all kind of observed aggregates. As an application to the case study of the 2010 eruption of Eyjafjallajökull volcano (Iceland), we also show how rafting can theoretically increase the travel distances of particles between 138–710 μm. These findings have fundamental implications for hazard assessment of volcanic ash dispersal as well as for weather modeling.


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