Computation of coaxial swirling with recirculation in a sudden expansion
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Computation of coaxial swirling with recirculation in a sudden expansion

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Published by UMIST in Manchester .
Written in English


Book details:

Edition Notes

StatementSupervised by: Leschziner, M.A..
ContributionsLeschziner, M. A., Supervisor., Mechanical Engineering (T.F.M.).
ID Numbers
Open LibraryOL20807394M

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Besides, the sudden expansion with a ratio of 2 in diameter between nozzle exits and the test chamber produces the boundary layer separation with the corresponding torus shape recirculation. Flow patterns for sudden-expansion and diffusers are contrasted for swirl number of 1 and expansion area ratio of 4 in a transitional turbulence regime. Diffusers have important influence on size and location of recirculation zones. Hence knowledge of flow characteristics is a prerequisite in the design by: 1. For the configurations with 60° and 45° expansion, no corner recirculation zone is observed and the swirling flow structure is asymmetric due to the non-axisymmetric dome geometry. The mathematical model is developed and the swirling two-phase flow behind a sudden tube expansion is simulated numerically using the model of Reynolds stress transport. The gas phase is described by the threedimensional RANS-equations taking into account the back effect of particles on transport processes in gas. To calculate the dispersed phase dynamics in a swirling confined flow, .

  Flow field characteristics of an axisymmetric sudden-expansion pipe flow with different initial swirl distribution A. S. Nejad and S. A. Ahmed Experimental Research Branch, Wright-Patterson AFB, Dayton, OH, USA The results of an experimental investigation depicting the effects of swirl profile on confined flows in a sudden-expansion coaxial dump combustor are presented. A momentum integral model for central recirculation in swirling flow in a sudden expansion The Canadian Journal of Chemical Engineering, Vol. 73, No. 3 Characterization of particle-laden, confined swirling flows by phase-doppler anemometry and numerical calculation.   Table 1 summarises past experimental investigations on sudden expansion flows. Both non-swirling and swirling studies are considered. Early experimental studies are reviewed by Devenport and Sutton () (non-swirling flows only) and Dellenback et al. ().It should be noted that swirling flows in complex industrial combustor geometries, jets or cyclones are not included in this table which.   Computation of strongly swirling axisymmetric free jets Discrete-phase effects on the flow field of a droplet-laden swirling jet with recirculation: A numerical study. International Journal of Heat and Fluid Flow, Vol. 13, No. 2. Hot flow analysis of swirling sudden-expansion dump combustor. International Journal for Numerical Methods in.

This paper reports the time-mean and phase-locked response of nonreacting as well as reacting flow field in a coaxial swirling jet/flame (nonpremixed). Two distinct swirl intensities plus two different central pipe flow rates at each swirl setting are investigated.   A helical flow in the guiding pipe breaks down near the sudden expansion to form a large bubble-like recirculation zone whose center moves slowly around the axis. Downstream of the bubble the core of the rotational large scale azimuthal flow motion is off the combustor axis and rotates around the axis at a frequency about 18–25 Hz (Strouhal. Turbulent premixed combustion is studied using experiments and numerical simulations in an acoustically uncoupled cylindrical sudden-expansion swirl combustor, and the impact of the equivalence ratio on the flame–flow characteristics is analyzed. In order to numerically capture the inherent unsteadiness exhibited in the flow, the large eddy simulation (LES) technique based on the artificial. The swirling flow of sudden-expansion dump combustor with central V-gutter flameholder and six side-inlets is studied by employing the SIMPLE-C algorithm and Jones-Launder k-e two-equation turbulent model. Both combustion models of one-step with infinite chemical reaction rate and two-step with finite chemical reaction rate of eddy-breakup (EBU) model are used to solve the present problem. The.