Volume No. 6 Issue No.: 3 Page No.: 569-574 Jan-Mar 2012

 

OXYGEN TRANSFER AT TURBULENT MICROSCALE

 

Bimlesh Kumar* and T. Thiyam Devi

Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati (INDIA)

 

Received on : October 15, 2011

 

ABSTRACT

 

An experimental and numerical investigation has been carried out to analyze the existence of local isotropy concept in geometrically similar surface aeration systems. Commercial software has been used in determining the small scale parameters such as microscale of turbulence and energy dissipation. Experimental observations have been carried out for oxygen transfer measurements in geometrically similar surface aeration systems. Two-film theory has been adopted in the measurement of oxygen transfer rate. It is found that microscale of turbulence and oxygen transfer are inversely related in geometrically similar surface aeration systems. Present work establishes the existence of local isotropy concept in higher turbulent flow conditions. Based on the local isotropy concept, the relationship of microscale of turbulence and rotational speed of rotor should exhibit the constancy, has been found in the present work. Empirical equation to simulate oxygen transfer rate in geometrical similar systems at turbulent microscale has been developed in the present work.

 

Keywords : Energy dissipation, Geometrical similarity, Local isotropy, Microscale of turbulence, Turbulent flow

 

 

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