Events Calendar

Astani CEE Oral Dissertation Defense

Speaker: Hyoung-Jin Kim, Ph.D. Civil Engineering Candidate

Talk Title: Numerical and Experimental Study on Dynamics of Unsteady Pipe Flow Involving Backflow Prevention Assembly

Abstract:
When control valves at the end of pipeline close simultaneously, two pressure waves are generated at each end and propagating toward to the other end. Those waves continue to go back and forth along pipelines until they are damped out to next steady states. This study provides information on the computer simulation of a rapid transient event called water hammer. The energy loss term due to friction in the unsteady model consists of quasi-steady contribution and unsteady contribution. For the present model, an equivalent friction coefficient is used to replace the quasi-steady friction coefficient, inclusive minor energy loss factors. The unsteady component has been related to the combination of the instant acceleration and instant convective acceleration. The numerical results of the present model are compared with the experimental records. The computer results based on the unsteady friction 1D model was successful to follow general trends of water hammer phenomena, corresponding with sudden changes in flow. This study later extends to the dynamic characteristics of backflow prevention assemblies under rapid transient condition. A numerical program for rapid transient pipe flow interconnected with a backflow prevention assembly has been developed using a coupling model and numerically solved by the method of characteristics.


Advisor: Professor Jiin Jen Lee

Location: Kaprielian Hall (KAP) - 335

Audiences: Everyone Is Invited

Contact: Evangeline Reyes