A comparison of single and multiphase jets in a crossflow using large eddy simulations

Summary, in English

Large eddy simulations (LES) are performed for single and multiphase jets in crossflow (JICF). The multiphase JICF are compared to the single-phase case for the same momentum and mass flow, ratios but with droplets of different sizes. Multiphase JICF have stronger counterrotating vortex pairs (CVPs) than a corresponding single-phase JICF. Moreover their trajectories are higher and their induced waves weaker. The smaller the Stokes number of the droplets, the more the solution approaches the solution for single-phase flow. The computed results show the formation of a CVP and horseshoe vortices, which are convected downstream. LES also reveals the intermittent formation of upright wake vortices from the horseshoe vortices oil the ground toward the CVP. The dispersion of polydisperse spray droplets is computed using the stochastic parcel method. Atomization and droplet breakup are modeled by a combination of the breakup model by Reitz and the Taylor analogy breakup model (see Caraeni, D., Bergstrom, C., and Fuchs, L., 2000, Flow, Turbid. Combust., 65(2), pp. 223-244). Evaporation and droplet collision are also modeled. The flow solver uses two-way coupling. Averages of the velocity and gaseous fuel mass fraction are computed. The single-phase JICF is validated against experimental data obtained by PIV. Additionally, the PDFs and frequency spectra are presented.

• Författare: Mirko Salewski; Dragan Stankovic; Laszlo Fuchs
• Avdelning/ar: Strömningsteknik
• Publiceringsår: 2007
• Språk: Engelska
• Sidor: 61-68
• Publikation/Tidskrift/Serie: Journal of Engineering for Gas Turbines and Power
• Volym: 129
• Issue: 1
• Länkar: http://dx.doi.org/10.1115/1.2180810
• Dokumenttyp: Artikel i tidskrift
• Förlag: American Society Of Mechanical Engineers (ASME)
• Ämne: Fluid Mechanics and Acoustics
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1528-8919