Turbulent Flow Pattern of Hyperboloid Stirring Reactor

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Franz Durst³  Murad Ismailov²  Masao Kuroda¹  Markus Schefer³ 

[1] Department of Civil Engineering, Gunma University;Department of Mechanical System Engineering, Gunma University;Institute of Fluid Mechanics (LSTM) of the Friedrich-Alexander-University

关键词: Stirred Tank Reactor;    Hyperboloid Stirrer;    Baffled Flow;    Laser-Doppler Anemometry;    Turbulent Kinetic Energy;   

DOI  :  10.1252/jcej.30.1090

来源: Maruzen Company Ltd

【 摘 要 】

References(12)Cited-By(2)3D periodical turbulent flow induced by a low shear hyperboloid stirrer in a fully baffled stirred tank reactor is experimentally studied at a constant Reynolds number, 5600, by using a diode fiber laser-Doppler anemometer. The ratio D:T:H of the hyperboloid stirrer diameter, D = 50 mm, the inner tank diameter, T, and the filled fluid height, H, is 1:3:3. Three low stands of hyperboloid stirrer clearance, D/10, D/7 and D/5, are also targeted to evaluate influence on flow structure. The experimental results are applied to verification of CFD-code based on a standard k–ε model.The flow field close to the hyperboloid stirrer is characterized by a series of vortex jets that are trailing periodically down within a radial extension of 0.5D to 0.7D. The maximum measured tangential velocity was 96% of the tip stirrer velocity. In this “near-of-flow area”, the kinetic energy is extensively dissipated itself due to impingement of velocity components. The axially-symmetric separation zone in the spatial form of λ-character induces two large-scale vortices above and below the separation. A highly rated kinetic energy lies within the head stream of λ-separation. Variation of the clearance at a factor less than D/5 sensibly influences flow structure and kinetic energy distribution. It is considered that computing on a turbulent hyperboloid flow field based on a k–ε model at a relatively high Reynolds number may result in a discharge of kinetic energy induced within the “near-of area”.

【 授权许可】

Unknown