Zobrazeno 1 - 10
of 67
pro vyhledávání: '"W. S. Lewellen"'
Publikováno v:
Journal of the Atmospheric Sciences. 65:3247-3262
Debris clouds provide an important visual signature of tornadoes and can potentially significantly affect the wind structure, damage potential, and Doppler radar measurements of tornado wind speeds. To study such issues, the dynamics of finescale deb
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a9fd59baeee03d271029b549fbbfeb2a
https://doi.org/10.1175/2008jas2686.1
https://doi.org/10.1175/2008jas2686.1
Autor:
W. S. Lewellen, David C. Lewellen
Publikováno v:
Journal of the Atmospheric Sciences. 64:2176-2194
An idealized analytical model and numerical large-eddy simulations are used to explore fluid-dynamic mechanisms by which tornadoes may be intensified near the surface relative to conditions aloft. The analytical model generalizes a simple model of Ba
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::51decd42e686339ffe4b56bf4fdb6c13
https://doi.org/10.1175/jas3965.1
https://doi.org/10.1175/jas3965.1
Autor:
W. S. Lewellen, David C. Lewellen
Publikováno v:
Journal of the Atmospheric Sciences. 64:2195-2209
Results are presented from a large set of large-eddy simulations of a class of unsteady vortex evolution that may sometimes play a role in tornadogenesis or tornado variability. Beginning with a high-swirl parent vortex with an excess of low-swirl fl
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f5808be11fbca6de5cd8b7c6d88c3bf5
https://doi.org/10.1175/jas3966.1
https://doi.org/10.1175/jas3966.1
Autor:
David C. Lewellen, W. S. Lewellen
Publikováno v:
Journal of the Atmospheric Sciences. 61:1147-1160
The modeling of the buoyancy flux in a partly cloudy atmospheric boundary layer is complicated by its dependence on the correlation between clouds and vertical velocity elements, which can vary significantly with the underlying layer dynamics (e.g.,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::84ddd3435f1897dfda8e69c8374dd0e6
https://doi.org/10.1175/1520-0469(2004)061<1147:bfmfcb>2.0.co
https://doi.org/10.1175/1520-0469(2004)061<1147:bfmfcb>2.0.co
Publikováno v:
Journal of the Atmospheric Sciences. 60:2820-2825
Since maximum Mach numbers in an F5 tornado are expected to, at least, reach ∼0.4, a study was undertaken to determine the major potential compressibility effects in such flows. Results from compressible large-eddy simulations of tornado corner flo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::834d73950bf120fd9c61c762fe0de355
https://doi.org/10.1175/1520-0469(2003)060<2820:iomnot>2.0.co
https://doi.org/10.1175/1520-0469(2003)060<2820:iomnot>2.0.co
Autor:
W. S. Lewellen, David C. Lewellen
Publikováno v:
Journal of the Atmospheric Sciences. 59:2966-2986
An idealized model of the relationship between entrainment in cloud-topped boundary layers, circulation structure, and the degree of decoupling between the cloud and subcloud layers is developed based on simple turbulent flux distributions and the pr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::054635322640bf82daba8300283c8e0d
https://doi.org/10.1175/1520-0469(2002)059<2966:eadrfc>2.0.co
https://doi.org/10.1175/1520-0469(2002)059<2966:eadrfc>2.0.co
Autor:
David C. Lewellen, W. S. Lewellen
Publikováno v:
Journal of Geophysical Research: Atmospheres. 106:27661-27672
High-resolution numerical large-eddy simulations of the near wake of a B757 including simplified NOx and HOx chemistry were performed to explore the effects of dynamics on chemistry in wakes of ages from a few seconds to several minutes. Dilution pla
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ccdf3df28babf2ecad6e61f4949f1ff6
https://doi.org/10.1029/2001jd000531
https://doi.org/10.1029/2001jd000531
Autor:
David C. Lewellen, W. S. Lewellen
Publikováno v:
Journal of the Atmospheric Sciences. 58:390-406
Results of large-eddy simulations of the development of young persistent ice contrails are presented, concentrating on the interactions between the aircraft wake dynamics and the ice cloud evolution over ages front a few seconds to approx. 30 min. Th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0ceb9696aefaa234841111a2f700d7bb
https://doi.org/10.1175/1520-0469(2001)058<0390:teoawd>2.0.co
https://doi.org/10.1175/1520-0469(2001)058<0390:teoawd>2.0.co
Publikováno v:
Journal of the Atmospheric Sciences. 57:527-544
The results of high-resolution, fully three-dimensional, unsteady simulations of the interaction of a tornado with the surface are presented. The goal is to explore some of the range of structures that should be expected to occur in nature within the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1739c4dbd32d040ed851f6eb34dc2b0a
https://doi.org/10.1175/1520-0469(2000)057<0527:tioals>2.0.co
https://doi.org/10.1175/1520-0469(2000)057<0527:tioals>2.0.co
Autor:
W. S. Lewellen, Lamont R. Poole, G. S. Kent, Robert J. DeCoursey, David C. Lewellen, G. M. Hansen, Chris A. Hostetler
Publikováno v:
AIAA Journal. 36:1439-1445
Results of large-eddy simulations of an aircraft wake are compared with results from ground-based lidar measurements made at NASA Langley Research Center during the Subsonic Assessment Near-Field Interaction Flight Experiment field tests. Brief revie
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2601c1406714324f6138da54c88d9de3
https://doi.org/10.2514/2.535
https://doi.org/10.2514/2.535