Estimation of average void fraction for gas-liquid, two-phase flow in an industrial nozzle assembly using a qudck-closing-valve

Azizur Rahaman, Johana Gomez, Ted Heidrick, Brian A. Fleck, Jennifer McMillan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Experimentally accurate void fraction measurements are a challenge in an air/water, two-phase flows through an industrial nozzle assembly, as a highly non-uniform void fraction exists in the feeding conduit prior to the nozzle. In this study, average void fractions were measured by isolating a section in the feeding conduit of a horizontal nozzle assembly, termed as the quick-closing-valve (QCV) technique. A high-speed video camera was utilized to capture the asynchronization closing time, tac. The average closing time and asynchronization for the pneumatically controlled valves were 200 ms and 2 ms, respectively. Based on the equation of 100umtac (1-α)/αlc, the synchronization error between the two valves was 1.12%, 1.26%, and 1.79% for the 1%, 2% and 4% ALR cases, respectively; here um is the mixture velocity, α is the void faction, and lc is the closing length. Higher synchronization error at 4% ALR occurs due to enhanced momentum in the flow regime. Experimental results indicate that the average α over the 33.4 cm feeding conduit (6.25 mm ID) was 76% (αtheoretical = 75%) for the 2% ALR, and 85% (αtheoretical = 83%) for the 3.3% ALR. In the two-phase, two-component flow the α affects the drop size and stability of the spray produced from an industrial nozzle assembly. Learning from this study will yield insights and conceptual understanding of two-phase flow phenomena in conduit, which would affect stability, pulsation tendency, and possibly atomization performance of the nozzle downstream. Two-phase flow nozzles have wide applications in the industries, e.g. petrochemical, pharmaceutical, and others.

Original languageEnglish
Title of host publication2008 Proceedings of the ASME Fluids Engineering Division Summer Conference, FEDSM 2008
Pages433-439
Number of pages7
Volume2
DOIs
Publication statusPublished - 2009
Externally publishedYes
Event2008 ASME Fluids Engineering Division Summer Conference, FEDSM 2008 - Jacksonville, FL, United States
Duration: 10 Aug 200814 Aug 2008

Other

Other2008 ASME Fluids Engineering Division Summer Conference, FEDSM 2008
CountryUnited States
CityJacksonville, FL
Period10/8/0814/8/08

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Keywords

  • High-speed video
  • Quick-closing-valve (QCV)
  • Synchronization error
  • Two-phase flow
  • Void fraction

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Mechanical Engineering

Cite this

Rahaman, A., Gomez, J., Heidrick, T., Fleck, B. A., & McMillan, J. (2009). Estimation of average void fraction for gas-liquid, two-phase flow in an industrial nozzle assembly using a qudck-closing-valve. In 2008 Proceedings of the ASME Fluids Engineering Division Summer Conference, FEDSM 2008 (Vol. 2, pp. 433-439) https://doi.org/10.1115/FEDSM2008-55334