Experimental Measurements of Expected Mass Fraction in a Contaminant Plume

Partha Sarathi, Roi Gurka, Paul J. Sullivan, Gregory A. Kopp

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


The sudden release of a quantity of gas into the atmospheric boundary layer produces a contaminant cloud. The expected mass fraction function provides a relatively simple measure of the contaminant concentration values found within the cloud and represents the ensemble-averaged fraction of the conserved release mass found at the different contaminant concentration intervals as the cloud evolves. The plume generated by a line source in grid turbulence is used to investigate the expected mass fraction function as it applies to scalar concentration values found on a typical line normal to the plume axis. Simultaneous particle image velocimetry and planar laser induced fluorescence are used to measure velocity and concentration fields, respectively. The measured expected mass fraction functions are observed to be approximately self-similar when concentration values are normalized by the centreline mean concentration. The moments of the expected mass fraction function are observed to be simply related to the centreline moments of the probability density function of scalar concentration. Arguments based on a source fluid, non-source fluid decomposition of the scalar probability density function are used to explain these observations. The results are compared with the theoretical and experimental results established for a line source of scalar in grid turbulence.

Original languageEnglish
Pages (from-to)167-185
Number of pages19
JournalBoundary-Layer Meteorology
Issue number2
StatePublished - 23 Jul 2010


  • Expected mass fraction
  • Moments
  • Particle image velocimetry
  • Planar laser induced fluorescence
  • Probability density function
  • Turbulent mixing

ASJC Scopus subject areas

  • Atmospheric Science


Dive into the research topics of 'Experimental Measurements of Expected Mass Fraction in a Contaminant Plume'. Together they form a unique fingerprint.

Cite this