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Varicose instabilities in turbulent boundary layers.

หน่วยงาน Nanyang Technological University, Singapore

รายละเอียด

ชื่อเรื่อง : Varicose instabilities in turbulent boundary layers.
นักวิจัย : Skote, M. , Haritonidis, J. H. , Henningson, D. S.
คำค้น : DRNTU::Engineering::Mechanical engineering::Fluid mechanics.
หน่วยงาน : Nanyang Technological University, Singapore
ผู้ร่วมงาน : -
ปีพิมพ์ : 2545
อ้างอิง : Skote, M., Haritonidis, J. H., & Henningson, D. S. (2002). Varicose instabilities in turbulent boundary layers. Physics of fluids, 14(7), 2309-2323. , http://hdl.handle.net/10220/18718 , http://dx.doi.org/10.1063/1.1482377 , 135422
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : Physics of fluids
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

An investigation of a model of turbulence generation in the wall region of a turbulent boundary layer is made through direct numerical simulations. The model is based on the varicose instability of a streak. First, a laminar boundary layer disturbed by a continuous blowing through a slot is simulated in order to reproduce and further investigate the results reported from the experiments of Acarlar and Smith [J. Fluid Mech. 175, 43 (1987)]. An isolated streak with an inflectional profile is generated that becomes unstable, resulting in a train of horseshoe vortices. The frequency of the vortex generation is equal to the experimental results. Comparison of the instability characteristics to those predicted through an Orr–Sommerfeld analysis are in good agreement. Second, a direct numerical simulation of a turbulent boundary layer is performed to point out the similarities between the horseshoe vortices in a turbulent and a laminar boundary layer. The characteristics of streaks and the vortical structures surrounding them in a turbulent boundary layer compare well with the model streak. The results of the present study show that one mechanism for the generation of horseshoe vortices in turbulent boundary layers is related to a normal inflectional instability of the streaks.

บรรณานุกรม :
Skote, M. , Haritonidis, J. H. , Henningson, D. S. . (2545). Varicose instabilities in turbulent boundary layers..
    กรุงเทพมหานคร : Nanyang Technological University, Singapore.
Skote, M. , Haritonidis, J. H. , Henningson, D. S. . 2545. "Varicose instabilities in turbulent boundary layers.".
    กรุงเทพมหานคร : Nanyang Technological University, Singapore.
Skote, M. , Haritonidis, J. H. , Henningson, D. S. . "Varicose instabilities in turbulent boundary layers.."
    กรุงเทพมหานคร : Nanyang Technological University, Singapore, 2545. Print.
Skote, M. , Haritonidis, J. H. , Henningson, D. S. . Varicose instabilities in turbulent boundary layers.. กรุงเทพมหานคร : Nanyang Technological University, Singapore; 2545.