Zobrazeno 1 - 10
of 50
pro vyhledávání: '"Toshihiko Hiejima"'
Autor:
Toshihiko Hiejima, Kaito Nishimura
Publikováno v:
AIP Advances, Vol 11, Iss 6, Pp 065123-065123-13 (2021)
This paper describes the improvement in combustion efficiency achieved using streamwise vorticity and fuel injections when using hypermixer struts at high Mach numbers. The effects of fuel injection conditions on combustion were investigated using nu
Externí odkaz:
https://doaj.org/article/5a7b91af1a0d459cae9a122624185567
Autor:
Toshihiko Hiejima
Publikováno v:
Journal of Fluid Mechanics; 10/25/2023, Vol. 973, pA41-1-A41-31, 31p
On the rapid breakdown of supersonic streamwise vortices with opposite sign double annular vorticity
Autor:
Toshihiko Hiejima
Publikováno v:
Acta Astronautica. 168:220-229
The spatial development of supersonic streamwise vortices with opposite-sign double annular vorticity is investigated using direct numerical simulation at Mach number 2.5. The results show that the unstable modes originate from inside or outside the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::29d8c8325774288f547d7462dff33e25
https://doi.org/10.1016/j.actaastro.2019.12.018
https://doi.org/10.1016/j.actaastro.2019.12.018
Autor:
Toshihiko Hiejima, Ryota Muraoka
Publikováno v:
Physics of Fluids. 34:116125
In this study, the formation conditions of the Mach disk in an underexpanded jet flow were numerically and theoretically investigated under sonic injection conditions and the assumption of an axisymmetric flow. The numerical results demonstrated that
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::faa4e1df897f3fb104584ffa41f098b3
https://doi.org/10.1063/5.0122861
https://doi.org/10.1063/5.0122861
Autor:
Yosei Maeda, Toshihiko Hiejima
Publikováno v:
Physics of Fluids. 34:096107
This study describes an improved scheme that can suppress numerical instabilities caused by calculating strong shock waves at high Mach numbers. The current scheme combines a clear detection of shock waves based on a sonic point condition with a hybr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::564290db23ea241841e13226f383c8b0
https://doi.org/10.1063/5.0102499
https://doi.org/10.1063/5.0102499
Autor:
Toshihiko Hiejima
Publikováno v:
Journal of Fluid Mechanics. 897
In this paper we investigate the instability properties of Batchelor vortices with a large swirl number and a fixed axial velocity deficit. In particular, it elucidates the effect of the helicity profile on the instability of the vortices as swirling
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::13609a3a6cd1e006a6350f51df517c51
https://doi.org/10.1017/jfm.2020.388
https://doi.org/10.1017/jfm.2020.388
Autor:
Toshihiko Hiejima
Publikováno v:
Computers & Fluids. 232:105199
This paper presents a weighted compact nonlinear scheme (WCNS) with high-order accuracy. The WCNS has the flexibility to select a numerical flux and is easily applied to general coordinates. In this study, the specific substencils of the original tar
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c752e86f18321b83c7931ed1deaf12bc
https://doi.org/10.1016/j.compfluid.2021.105199
https://doi.org/10.1016/j.compfluid.2021.105199
Autor:
Toshihiko Hiejima
Publikováno v:
Physical Review Fluids. 4
Compressibility effects mean that fluctuation growth related to turbulence is suppressed as Mach number increases. An investigation that clarifies compressibility effects of the Batchelor vortex is presented. The findings indicate that entropy fluctu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4f3271ffdd5f7c0b0c33a8b618d8376d
https://doi.org/10.1103/physrevfluids.4.093903
https://doi.org/10.1103/physrevfluids.4.093903
Autor:
Toshihiko Hiejima
Publikováno v:
Physics of Fluids. 32:076107
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c5cb7e5ea01e186c50bc405a8cbc0926
https://doi.org/10.1063/5.0014192
https://doi.org/10.1063/5.0014192
Autor:
Toshihiko Hiejima
Publikováno v:
Computers & Fluids. 201:104416
Growth processes in supersonic streamwise vortices with linear unstable modes at Mach numbers 2.5 and 5.0 were numerically investigated using a weighted compact nonlinear scheme (WCNS) with three different accuracies. In the evolution of the inviscid
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::38d46bc58463eb5f572041b1757b53e2
https://doi.org/10.1016/j.compfluid.2019.104416
https://doi.org/10.1016/j.compfluid.2019.104416