New prediction methods for CO2 evaporation inside tubes: Part 1 - A two-phase flow pattern map and a flow pattern based phenomenological model for two-phase flow frictional pressure drops

Lixin Cheng, Gherhardt Ribatski, Jesús Moreno Quibén, John R. Thome

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126 Citations (Scopus)


An updated flow pattern map was developed for CO2 on the basis of the previous Cheng–Ribatski–Wojtan–Thome CO2 flow pattern map [1] and [2] to extend the flow pattern map to a wider range of conditions. A new annular flow to dryout transition (A–D) and a new dryout to mist flow transition (D–M) were proposed here. In addition, a bubbly flow region which generally occurs at high mass velocities and low vapor qualities was added to the updated flow pattern map. The updated flow pattern map is applicable to a much wider range of conditions: tube diameters from 0.6 to 10 mm, mass velocities from 50 to 1500 kg/m2 s, heat fluxes from 1.8 to 46 kW/m2 and saturation temperatures from -28 to +25 °C (reduced pressures from 0.21 to 0.87). The updated flow pattern map was compared to independent experimental data of flow patterns for CO2 in the literature and it predicts the flow patterns well. Then, a database of CO2 two-phase flow pressure drop results from the literature was set up and the database was compared to the leading empirical pressure drop models: the correlations by Chisholm [3], Friedel [4], Grönnerud [5] and Müller-Steinhagen and Heck [6], a modified Chisholm correlation by Yoon et al. [7] and the flow pattern based model of Moreno Quibén and Thome [8], [9] and [10]. None of these models was able to predict the CO2 pressure drop data well. Therefore, a new flow pattern based phenomenological model of two-phase flow frictional pressure drop for CO2 was developed by modifying the model of Moreno Quibén
Original languageEnglish
Pages (from-to)111-124
Number of pages14
JournalInternational Journal of Heat and Mass Transfer
Issue number1-2
Early online date7 Jun 2007
Publication statusPublished - Jan 2008



  • model
  • flow pattern map
  • flow patterns
  • phenomenological
  • flow boiling
  • two-phase flow
  • frictional pressure drop
  • macrochannel
  • microchannel
  • CO2

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