LEADER 00000nam  2200313   4500 
001    AAI3271575 
005    20081111094051.5 
008    081111s2007    ||||||||||||||||| ||eng d 
020    9780549111467 
035    (UMI)AAI3271575 
040    UMI|cUMI 
100 1  Patel, Nayan 
245 10 Simulation of hydrodynamic fragmentation from a 
       fundamental and an engineering perspective 
300    272 p 
500    Source: Dissertation Abstracts International, Volume: 68-
       07, Section: B, page: 4623 
500    Adviser: Suresh Menon 
502    Thesis (Ph.D.)--Georgia Institute of Technology, 2007 
520    Liquid fragmentation phenomenon is explored from both a 
       fundamental (fully resolved) and an engineering (modeled) 
       perspective. The dual objectives compliment each other by 
       providing an avenue to gain further understanding into 
       fundamental processes of atomization as well as to use the
       newly acquired knowledge to address practical concerns. A 
       compressible five-equation interface model based on a Roe-
       type scheme for the simulation of material boundaries 
       between immiscible fluids with arbitrary equation of state
       is developed and validated. The detailed simulation model 
       accounts for surface-tension, viscous, and body-force 
       effects, in addition to acoustic and convective transport.
       The material interfaces are considered as diffused zones 
       and a mixture model is given for this transition region. 
       The simulation methodology combines a high-resolution 
       discontinuity capturing method with a low-dissipation 
       central scheme resulting in a hybrid approach for the 
       solution of time- and space-accurate interface problems. 
       Several multi-dimensional test cases are considered over a
       wide range of physical situations involving capillary, 
       viscosity, and gravity effects with simultaneous presence 
       of large viscosity and density ratios. The model is shown 
       to accurately capture interface dynamics as well as to 
       deal with dynamic appearance and disappearance of material
520    Simulation of atomization processes and its interaction 
       with the flow field in practical devices is the secondary 
       objective of this study. Three modelling requirements are 
       identified to perform Large-Eddy Simulation (LES) of spray
       combustion in engineering devices. In concurrence with 
       these requirements, LES of an experimental liquid-fueled 
       Lean Direct Injection (LDI) combustor is performed using a
       subgrid mixing and combustion model. This approach has no 
       adjustable parameters and the entire flow-path through the
       inlet swirl vanes is resolved. The inclusion of the 
       atomization aspects within LES eliminates the need to 
       specify dispersed-phase size-velocity correlations at the 
       inflow boundary. Kelvin-Helmholtz (or aerodynamic) breakup
       model by Reitz is adopted for the combustor simulation. 
       Two simulations (with and without breakup) are performed 
       and compared with measurements of Cai et al. Time-averaged
       velocity prediction comparison for both gas- and liquid-
       phase with available data show reasonable agreement. The 
       major impact of breakup is on the fuel evaporation in the 
       vicinity of the injector. Further downstream, a wide range
       of drop sizes are recovered by the breakup simulation and 
       produces similar spray quality as in the no-breakup case 
590    School code: 0078 
590    DDC 
650  4 Engineering, Aerospace 
690    0538 
710 2  Georgia Institute of Technology 
773 0  |tDissertation Abstracts International|g68-07B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/