Acoustic modes in jet and wake stability

assessing political stability and instability in central asia and caucasus; case study, azerbaijan and kyrgyzstan

منطقه ی آسیای مرکزی وقفقاز به عنوان منطقه ای تاریخی و به دلیل دارا بودن ذخایر عظیم هیدرو کربنی از اهمیت ویژه ای برخوردار است. کشورهای این منطقه از عوامل عمده ی بی ثباتی نظیر عوامل جغرافیایی، اقتصادی، امنیتی، اجتماعی و سیاسی رنج می برند. پس از فروپاشی اتحاد جماهیر شوروی کشورهای منطقه از نعمت استقلال ناخواسته ای برخوردار شدند که مشکلات فوق را برای آن ها چندین برابر می کرد. در این روند برخی از این...

Idle-time energy savings through wake-up modes in underwater acoustic networks

1570-8705/$ see front matter 2008 Elsevier B.V doi:10.1016/j.adhoc.2008.07.014 q A short version of this work was presented at W * Corresponding author. Tel.: +1 91 3 207 9666. E-mail addresses: [email protected] (A.F. Harris), Stojanovic), [email protected] (M. Zorzi). 1 Funded in part by NSF Grants 0520075 and 0427 Interest in underwater sensor networks has increased recently due to the poss...

Turbulent wake past a three-dimensional blunt body. Part 1. Global modes and bi-stability

Super- and multi-directive acoustic radiation by linear global modes of a turbulent jet

The mean flow stability of a Mach 0.9 turbulent jet is investigated by means of global linear theory with a focus on acoustic effects. A novel class of resonant acoustic modes that are trapped within the potential core, and whose eigenvalues appear as discrete branches in the global stability spectrum, is studied in detail. A dispersion relation is reconstructed from the global modes, and shown...

Jet dynamics and stability

The dynamics and stability of extragalactic jets may be strongly influenced by small (and probable) differences in pressure between the jet and the ambient and within the jet itself. The former give rise to expansion and recollimation of the jet. This occurs in the form of conical shocks, or Mach disks, if the pressure difference is large enough. Pressure asymmetries within the jet may trigger ...