Hydrodynamic Analyses of the Flow Patterns in Stirred Vessel of Two-Bladed Impeller

Abstract

In this paper, the governing equations of continuity and momentum subjected to suitable boundary conditions have been solved numerically to investigate the fluid flow in stirred vessel of two-bladed impeller. The numerical simulations have been carried out in three-dimensions for laminar flow. The studied fluid was considered Newtonian and incompressible. Our research studied the effects of geometrical configurations of the two-bladed impeller and its rotational speed on fluid patterns and mechanical power consumption. The innovative point in this paper is that the blades of the impeller contain three equal-sized holes of circular cross-section. The diameter of the hole (d) to the impeller diameter (D) gives the ratio d/D. the impeller speed is controlled by the Reynolds number (Re). The obtained results have been illustrated and discussed for the range of following governing parameters: d/D = 0 to 0.4 and Re = 1 to 300. The results showed that the studied parameters have significant effects on fluid flow and consumption power and the perforated blades of ratio d/D = 0.133 is more efficient than plan blades. Also, a new correlation is proposed to describe the consumption power as function of d/D and Re.

Study of the effect of geometric shape on the quality of mixing: Examining the effect of length of the baffles

“…But as the fluid speed increases, either by increasing the rotational speed or increasing the number of blades, this gradually dampens these vortices. This observation is similar to the one that was made in the previous work [2]. In other words, when the movement of the impeller is weak, vortices form near the impeller, while they disappear when the mixing speed increases.…”

“…The first part is fixed and includes the walls of the vessel with the baffles, while the second is in rotation and includes the impeller. This technique was used in many previous works, including [2,18,19]. In the absence of baffles inside the vessel, a rotating reference frame (RRF) can be used as in works [1,3,8].…”

“…The results of the research showed that this new form has the ability to raise the quality of mixing. Laidoudi [2] accomplished a numerical work on the effect of shape of the mixer on the quality of mixing. The form studied in this paper consists in holes in the blades of the two-bladed agitator.…”

A qualitative study of mixing a fluid inside a mechanical mixer with the effect of thermal buoyancy

“…The results of simulation were presented as contours of velocity and vectors [11]. Laidoudi presented a numerical work on a two-bladed impeller placed in an unbaffled vessel [12]. Some new geometrical modifications were considered to improve the performance of the impeller.…”

3D simulation of incompressible flow a rounda rotating turbulator: Effect of rotational and direction speed

“…Many recent studies aim to induce geometric changes for the purpose of accelerating the flow within the channel. This dynamic behaviour can be exploited to speed up the fluid mixing process [1][2][3], or increase the process transferring in thermal applications [4][5][6]. Previous studies showed that the presence of a solid body inside a channel accelerates the movement of the flow as it passes around this body.…”