Flow Visualization of Internal Waves and Wakes of a Streamlined Body in a Stratified Fluid
- سال انتشار: 1395
- محل انتشار: دوماهنامه مکانیک سیالات کاربردی، دوره: 9، شماره: 2
- کد COI اختصاصی: JR_JAFM-9-2_013
- زبان مقاله: انگلیسی
- تعداد مشاهده: 187
نویسندگان
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
The Institute of Geophysics, University of Tehran, Tehran, Iran
چکیده
The wake and internal waves of a moving three dimensional (۳D) airfoil body in a stratified fluid has been investigated in a large stratified tank with a finite depth using movies of shadowgraphs of the flow fields. Typical Reynolds and Froude numbers of the flow varied between ۱۰۳ and ۱۰۴, and ۰.۳ and ۲ respectively. The flows are generated often by towing the body in a uniformly stratified flow, while limited cases are carried out with body stationary and the channel was in recirculating mode. For some experiments the density profile had a stepped like shape. The wake flow is often consisted of internal waves including random and coherent ones. Distortion of density fields was also observed ahead and above the body in cases where the Froude number was subcritical. Results show that as the Froude number (Fr=U/Nh, where U is the body relative velocity, N is buoyancy frequency and h is the thickness of the body) is increased, the flow undergoes from a subcritical narrow wake (for Fr۱). Typical wavelength of the exited internal waves is increased with Fr, as the theory predicts. The wake of the flow for Fr> ۱.۴ appeared to collapse and some internal waves emission from it could be observed. Usually two types of internal waves, namely random small scale and large scale, more regular waves are observed.کلیدواژه ها
Stratified tank, Airfoil body, Internal lee waves, Flow shadowgraphs, Wakeاطلاعات بیشتر در مورد COI
COI مخفف عبارت CIVILICA Object Identifier به معنی شناسه سیویلیکا برای اسناد است. COI کدی است که مطابق محل انتشار، به مقالات کنفرانسها و ژورنالهای داخل کشور به هنگام نمایه سازی بر روی پایگاه استنادی سیویلیکا اختصاص می یابد.
کد COI به مفهوم کد ملی اسناد نمایه شده در سیویلیکا است و کدی یکتا و ثابت است و به همین دلیل همواره قابلیت استناد و پیگیری دارد.