Drag reduction in turbulent flow by polymer additive with longitudinal excitation

Pao Yue-kong Library Electronic Theses Database

Drag reduction in turbulent flow by polymer additive with longitudinal excitation

 

Author: Mo, Mun Tong
Title: Drag reduction in turbulent flow by polymer additive with longitudinal excitation
Degree: M.Sc.
Year: 1995
Subject: Frictional resistance (Hydrodynamics)
Turbulence
Polymer solutions
Hong Kong Polytechnic University -- Dissertations
Department: Dept. of Mechanical Engineering
Multi-disciplinary Studies
Pages: viii, 87 leaves : ill. ; 30 cm
Language: English
InnoPac Record: http://library.polyu.edu.hk/record=b1219800
URI: http://theses.lib.polyu.edu.hk/handle/200/2924
Abstract: It has been known for many year that solutions of high polymers can be irreversibly reduced by ultrasonic irradiation or high speed stirring. Experimental studies of drag reduction and polymer degradation in turbulent flow with dilute water solution of a brass pipe under the forced excitation at the end of the pipe are described. The fundamental natural frequency of the testing section is employed to intensify the excitation effect. Two sets of experiments (1) no excitation; (2) with excitation at four different Reynolds Numbers are undertaken to investigate the influence of excitation. The trend of the friction factor and percentage of drag reduction are interpreted and justified in term of number of passes and time. Moreover, the mechanical degradation of the polymer under excitation is also concerned, and the obtained results are compared with the un-excited flow. A formula of the relationship between the required time for an excited flow to catch up with the gross flow and its Reynolds No. is developed. It therefore seems likely that the excitation of the pipe can enlarge the rate of polymer degradation.

Files in this item

Files Size Format
b12198006.pdf 2.477Mb PDF
Copyright Undertaking
As a bona fide Library user, I declare that:
  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

     

Quick Search

Browse

More Information