Drag Reduction of Bamboo and Abaca Fiber Suspensions in Circular Pipe

2013 ◽  
Vol 388 ◽  
pp. 34-39 ◽  
Author(s):  
Gunawan Kapal ◽  
M. Baqi ◽  
S. Fathernas ◽  
Yanuar
Keyword(s):  
Aqueous Solution ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Aqueous Solutions ◽  
Drag Reduction ◽  
High Reynolds Number ◽  
Circular Pipe ◽  
Fiber Suspensions ◽  
Maximum Drag Reduction ◽  
High Reynolds

The drag reduction of dispersions of fibers in aqueous solutions of was studied as a function of concentration with a circular pipe apparatus. Experiments were carried out by measuring the pressure drop. The purpose of this research is to investigate the reduction of pressure drop in a circular pipe with the addition fiber in aqueous solution. Circular pipe with 4 mm of diameter is used in this study. Concentration of bamboo and abaca fibers solutions are 200 ppm and 300 ppm. It was found that fibers solutions give rise to drag reduction in turbulent flow range. Experimental was conducted from low to high Reynolds number up to 55,000. We observed a maximum drag reduction ratio of 7 % at Reynolds number about 35,000 and found that increased by increasing a concentration of fiber solution.

High Reynolds Number Micro-Bubble and Polymer Drag Reduction Experiments

2008 ◽  
Author(s):  
Steven L. Ceccio ◽  
David R. Dowling ◽  
Marc Perlin ◽  
Michael Solomon
Keyword(s):  
Reynolds Number ◽  
Drag Reduction ◽  
High Reynolds Number ◽  
Polymer Drag Reduction ◽  
Micro Bubble ◽  
High Reynolds

Friction Factor Directly From Roughness Measurements

2001 ◽  
Author(s):  
Elling Sletfjerding ◽  
Jon Steinar Gudmundsson
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Power Spectrum ◽  
Friction Factor ◽  
High Reynolds Number ◽  
Gas Flow ◽  
Relative Roughness ◽  
High Reynolds ◽  
Friction Factor Correlation ◽  
Roughness Measurements

Abstract Pressure drop experiments on natural gas flow in 150 mm pipes at 80 to 120 bar pressure and high Reynolds number were carried out for pipes smooth to rough surfaces. The roughness was measured with an accurate stylus instrument and analyzed using fractal methods. Using a similar approach to that of Nikuradse the measured friction factor was related to the measured roughness values. Taking the value of the relative roughness and dividing it by the slope of the power spectrum of the measured roughness, a greatly improved fit with the measured friction factor was obtained. Indeed, a new friction factor correlation was obtained, but now formulated in terms of direct measurement of roughness.

Pressure Drop in a Pebble Bed Reactor Under High Reynolds Number

2012 ◽  
Vol 180 (2) ◽  
pp. 159-173 ◽  
Author(s):  
Yassin A. Hassan ◽  
Changwoo Kang
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
High Reynolds Number ◽  
Pebble Bed ◽  
Pebble Bed Reactor ◽  
High Reynolds

scholarly journals High-Reynolds-number weakly stratified flow past an obstacle

1996 ◽  
Vol 317 ◽  
pp. 155-178 ◽  
Author(s):  
S. I. Chernyshenko ◽  
Ian P. Castro
Keyword(s):  
Reynolds Number ◽  
Drag Reduction ◽  
Turbulent Flows ◽  
High Reynolds Number ◽  
Bluff Body ◽  
Physical Mechanisms ◽  
Flow Past ◽  
Large Channel ◽  
Weak Stratification ◽  
High Reynolds

Stably stratified steady flow past a bluff body in a channel is considered for cases in which the stratification is not sufficiently strong to give solutions containing wave motions. The physical mechanisms by which stratification influences the flow are revealed. In particular, the drag reduction under weak stratification, observed in experiments, is explained. This is achieved by constructing an asymptotic laminar solution for high Reynolds number (Re) and large channel width, which explicitly gives the mechanisms, and using comparisons with numerical results for medium Re and experiments for turbulent flows to argue that these mechanisms are expected to be common in all cases. The results demonstrate the possibility, subject to certain restrictions, of using steady high-Re theory as a tool for studying qualitative features of real flows.

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