Minimization of stresses and pressure surges in pipes using nonlinear optimization.

The control of stresses and liquid pressure surges in pipes is an important problem in the design of hydraulic pipe networks. The method of characteristics has been used to solve the transient stresses and pressures in liquid-filled piping systems. The friction force is included in the equations of motion for the fluid and the pipe wall. The maximum pressure and maximum stress at any point along the length of the pipe are evaluated for the entire simulation time. A nonlinear search technique has been developed using the simplex method. The optimal valve closure is sought, that will minimize the maximum pressure and/or stresses. A continuous optimal valve closure policy is specified using spline functions. Numerical examples are presented showing the reduction of the dynamic pressure and the dynamic stress from linear valve closure to optimal valve closure for a simple pipeline and a complex pipeline. Also, a method for choosing the shortest time of closure which will keep the stresses below specified allowable stresses is presented.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Civil Engineering and Engineering Mechanics

Grantor dc:publisher

The University of Arizona.

Year dc:date.issued

1989

Author dc:creator

• El-Ansary, Amgad Saad Eldin.

Advisor dc:contributor.advisor

• Contractor, D. N.

Committee members dc:contributor.committeemember

• Nowatzki, E. A.
• Kiouis, P. D.
• Sen, S.

• Tubes -- Mechanical properties.
• Fluid dynamics.
• Strains and stresses.

Statement dc:rights

• Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10150/184632

OAI identifier oai:identifier

oai:repository.arizona.edu:10150/184632