Istraživanje turbulentnog dvofaznog strujanja u pravim kanalima pneumatskog transporta granularnog materijala nekružnog poprečnog preseka
Research of two phase turbulent flow of granular material pneumatic transport in straight channels with noncircular cross section
Докторанд
Milanović, SašaМентор
Ilić, GradimirЧланови комисије
Stevanović, ŽarkoBogdanović, Božidar
Метаподаци
Приказ свих података о дисертацијиСажетак
The two-phase turbulent flows of gas-solid particles, in the channels of noncircular
cross-section (square, rectangular, etc.), are very often encountered in
engineering practice. Examples of this flows type can be found in ventilation
systems and air conditioning, in systems for pneumatic transport of granular
materials, in turbo machines, heat exchangers, nuclear reactors, open channels,
etc. Two-phase flows of gas-solids are characterized by a variety of phenomena
which are a consequence of interaction the gas and the solid phases.
In these channels beside the main stream along the channel occur
secondary flows in the plane of the channel cross section. The mechanisms that
lead to the secondary flows are different (curved channels, different temperature
load of channel walls etc.). This type of flows, known as Prandtl’s secondary flow
of the first kind, was the subject of a large number of researchers.
A special flow phenomenon which occurs in straight channels in the regime
of full...y developed turbulent flow is a secondary flow of the second kind, known in
the literature as secondary flow of Prandtl's second kind. To this problem is a very
little attention has been paid so far in research practice.
This flow has a significant impact in the total mechanism of mass, impulse
and heat transfer in the channel and in environment. Transfers of high intensity
impulses in the channel have as a consequence large gradients of transversal
velocity in the plane of channel cross section. Produced secondary flow increase
shear stress in the corners of the channels and has a significant effect on the
intensity of heat transfer from fluid to the wall of the channel, and vice versa.
These are some of the reasons why special attention to the phenomenon of
secondary currents of the second kind in the two-phase system gas-solid particles
is given in this paper. Considered flow is turbulent, steady, incompressible and
fully developed in the straight channel of square cross-section, whose walls have a
constant temperature different from the environmental temperature.
Факултет:
Универзитет у Нишу, Машински факултетДатум одбране:
2013Пројекти:
- Ревитализација постојећих и пројектовање нових микро и мини хидроелектрана (од 100 до 1000 kW) на територији јужне и југоисточне Србије (RS-MESTD-Technological Development (TD or TR)-33040)
- Истраживање магнетнохидродинамичких струјања (MHD) у околини тела, процепима и каналима и примена у развоју MHD пумпи (RS-MESTD-Technological Development (TD or TR)-35016)