Experimental study of pressure drop and wall shear stress characteristics of γ Al2O3-water nanofluid in a circular pipe under turbulent flow induced vibration

الملخص EN

Experimental study of γ /Al2O3 with mean diameter of less than 50 nm was dispersed in the distilled water that flows through a pipe consist of five sections as work station ,four sections made of carbon steel metal and one sections made of Pyrex glass pipe, with five nanoparticles volume concentrations of 0%,0.1%,0.2%,0.3%,and 0.4% with seven different volume flow rates 100, 200 , 300, 400, 500, 600 ,and 700ℓ/min were investigated to calculated pressure distribution for the cases without rubber ,with 3mm rubber and with 6mm rubber used to support the pipe.

Reynolds number was between 20000 and 130000.

Frequency value through pipe was measured for all stations of pipe for all cases.

The results show that the pressure drop and wall shear stress of the nanofluid increase by increasing the nanoparticles volume concentrations or Reynolds number, the values of frequency through the pipe increase continuously when wall shear stress increases and the ratio of increment increases as nanofluid concentrations increase.

Increasing of vibration frequency lead to increasing the friction factor between the pipe and the wall and thus increasing in pressure drop.

Several equations between the wall shear stress and frequency for all volume concentration and for three cases without rubber, with rubber has 3mm thickness ,and with rubber has 6mm thickness.

Finally, the results led to that γ /Al2O3 could function as a good and alternative conventional working fluid in heat transfer applications.

A good agreement is seen between the experimental and those available in the literature.