Numerical analysis of transient flow through a pipe orifice (Time constant for settling flow)

Toshiyuki Hayase, Ping Cheng, Satoru Hayashi

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


As a fundamental consideration in hydraulic valve dynamics, transient flow through a pipe orifice has been studied via a numerical analysis. Steady axisymmetric viscous fluid flow was first investigated to confirm the present SIMPLER-based finite volume methodology. Time-dependent calculation for a suddenly imposed pressure gradient has shown two distinct characteristic time constants for the transient state. The first characteristic time is commonly considered to correspond to the flow rate change, while the second one concerning the variation of flow structure has not been treated in earlier studies. The final settling of flow is completed in the second characteristic time which is almost ten times larger than the first one under the present condition.

Original languageEnglish
Pages (from-to)157-163
Number of pages7
JournalJSME International Journal, Series B: Fluids and Thermal Engineering
Issue number2
Publication statusPublished - 1995

ASJC Scopus subject areas

  • Mechanical Engineering
  • Physical and Theoretical Chemistry
  • Fluid Flow and Transfer Processes


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