scholarly journals Numerical study on phase change of water flowing across two heated rotating circular cylinders in tandem arrangement

2016 ◽  
Vol 8 (4) ◽  
pp. 201-212
Author(s):  
BK Dhar ◽  
SK Mahapatra ◽  
SK Maharana ◽  
A Sarkar ◽  
SS Sahoo

The problems of fluid flow and heat transfer phenomena over an array of cylinders are quite prominent in fluid dynamics and industry applications. The current work focuses on fluid flow and heat transfer analysis over two heated rotating cylinders arranged in tandem. The flow of water over heated cylinders faces a phenomenon of phase change from liquid (water) to vapor phase (steam). The mechanism of this phase change is studied through a numerical simulation supplemented with verification of the code and validation. The problem is simulated when flows from two cylinders in a tandem arrangement become interacting and non-interacting. The Eulerian model is used during simulation to comprehend the multiphase phenomena. The volume fractions of both the phases such as water and vapor and heat transfer coefficients of both the cylinders have been computed and presented as findings of the problem. The mass and heat transfer mechanism is unidirectional from one phase to the other phase. The vapor fraction of each phase is to be observed and compared when three different rotations are given to the two cylinders immersed in a turbulent flow of water.

10.30544/481 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Houssem Laidoudi

The two-dimensional numerical investigation is well accomplished to understand the behavior of buoyancy-driven flow in closed annular space. The studied domain consists of a pair of equal-sized circular cylinders in tandem arrangement confined in a circular enclosure which is filled with incompressible Newtonian fluid. The inner cylinders are identical in size and they are supposed to be hot with constant temperature, the outer circular enclosure is kept cold with a constant temperature. The descriptive governing equations of continuity, momentum and energy for the present problem are solved numerically using the finite-volume method. The present research studies the effects of thermal buoyancy strength, the thermophysical characteristics of the fluid, and the size of the inner cylinders on the flow patterns inside the circular domain and rate of heat transfer exchanging between the inner cylinders and fluid flow. The results showed that the studied governing parameters significantly affect the fluid flow and heat transfer rate. An increase in the diameter of inner cylinders makes the effect of buoyancy strength on fluid flow and heat transfer negligible for all values of thermo-physical parameters. Also, the average Nusselt number of each inner cylinder is computed and plotted for industrial applications.


2015 ◽  
Vol 9 (3) ◽  
pp. 242 ◽  
Author(s):  
Efstathios Kaloudis ◽  
Dimitris Siachos ◽  
Konstantinos Stefanos Nikas

2021 ◽  
Vol 321 ◽  
pp. 04007
Author(s):  
Abdelkader Boutra ◽  
Seddik Kherroubi ◽  
Abderrahmane Bourada ◽  
Youb Khaled Benkahla ◽  
Nabila Labsi ◽  
...  

Flow and heat transfer analysis in ventilated cavities is one of the most widely studied problems in thermo-fluids area. Two-dimensional mixed convection in a ventilated rectangular cavity with baffles is studied numerically and the fluid considered in this study is hot air (Pr = 0.71). The horizontal walls are maintained at a constant temperature, higher than that imposed on the vertical ones. Two very thin heat-conducting baffles are inserted inside the enclosure, on its horizontal walls, to control the flow of convective fluid. The governing equations are discretized using the finite volume method and the SIMPLER algorithm to treat the coupling velocity–pressure. Line by line method is used to solve iteratively the algebraic equations. The effect of the Richardson number Ri (0.01- 100) and the location of the baffles within the cavity on the isothermal lines, streamlines distributions and the average Nusselt number (Nu) has been investigated. The result shows that the location opposite the baffles, close to the fluid outlet, is the optimal choice to be considered for industrial applications.


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