<b>Numerical investigation of flow induced by a disc turbine in unbaffled stirred tank</b> - doi: 10.4025/actascitechnol.v35i3.15554

Abstract

ABSTRACT. The flow generated by a disc turbine in a cylindrical unbaffled tank was numerically modeled. This study was carried out for shear-thinning fluids. Analyses concern the effect of impeller rotational speed, fluid rheology and impeller blade curvature on the mean velocities and power consumption. It was found that the cavern size and the power consumption are higher for extreme shear thinning fluids. It was found also that the best performance is achieved at high Reynolds number and flat-blade turbine. Predictions have been compared with literature data and a satisfactory agreement has been found.Keywords: numerical study, stirred tank, shear thinning fluid, disc turbine, impeller location, blade curvature.Investigação numérica do fluxo induzido por uma turbina de disco em 'unbaffled' tanque de agitação RESUMO. O fluxo gerado por uma turbina de disco em um tanque cilíndrico unbaffled foi numericamente modelada. Este estudo foi realizado para corte fino fluidos. As análises dizem respeito ao efeito da velocidade de rotação do rotor, reologia de fluidos e curvatura da lâmina do rotor na velocidade média e consumo de energia. Verificou-se que o tamanho da caverna eo consumo de energia são maiores para diluir os fluidos de corte extremas. Verificou-se também que o melhor desempenho é alcançado em número de Reynolds alto e flat-blade turbina. Previsões foram comparados com dados da literatura e um acordo satisfatório foi encontrado.Palavras-chave: estudo numérico, tanque de agitação, fluido pseudoplástico, disco turbina, localização do rotor, a curvatura da lâmina.

Energy efficiency of a deep hollow bladed impeller for mixing viscoplastic fluids in a cylindrical vessel

“…In our previous article, 9 we have studied the effect of blade curvature on the power consumption, and the obtained results have revealed that the increase in blade The impeller design plays a great role in the performance of a mixing system; in order to check this knowledge, we have realized four geometrical configurations by changing the radial dimension (d/D = 0.3, 0.4, 0.5, and 0.6, respectively) and four others by changing the axial dimension of the blade (h/D = 0.06, 0.1, 0.14, and 0.18, respectively).…”

“…In our previous article, 9 we have studied the effect of blade curvature on the power consumption, and the obtained results have revealed that the increase in blade Figures 8 and 9, respectively. It is clear that values of Np and Nq will be greater with increased blade width.…”

“…[1][2][3][4] Recently, many researchers focus on the performance of impellers with curved blades, and some works have been achieved using this type of impellers to study the flow pattern generated with rheological complex fluids. [5][6][7][8][9][10][11][12][13] Other researchers interested to Newtonian fluids with curved blade impellers in single or dual arrangements. [14][15][16] Concerning the curved blades, all of these studies used a Scaba 6SRGT, a Scaba 3SHPI, HE-3, Lightnin A320, or a Maxflo turbine.…”

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

“…The investigations showed the effects of rotational speed, rheological characteristics and impeller clearance on the power consumption. Ameur and Bouzit simulated the rotation of a disc turbine impeller in the unbaffled vessel [4]. The working fluid was shear-thinning.…”