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Numerical modeling for dilute and dense spraysWe have successfully implemented a numerical model for spray-combustion calculations. In this model, the governing gas-phase equations in Eulerian coordinate are solved by a time-marching multiple pressure correction procedure based on the operator-splitting technique. The droplet-phase equations in Lagrangian coordinate are solved by a stochastic discrete particle technique. In order to simplify the calculation procedure for the circulating droplets, the effective conductivity model is utilized. The k-epsilon models are utilized to characterize the time and length scales of the gas phase in conjunction with turbulent modulation by droplets and droplet dispersion by turbulence. This method entails random sampling of instantaneous gas flow properties and the stochastic process requires a large number of computational parcels to produce the satisfactory dispersion distributions even for rather dilute sprays. Two major improvements in spray combustion modelings were made. Firstly, we have developed a probability density function approach in multidimensional space to represent a specific computational particle. Secondly, we incorporate the Taylor Analogy Breakup (TAB) model for handling the dense spray effects. This breakup model is based on the reasonable assumption that atomization and drop breakup are indistinguishable processes within a dense spray near the nozzle exit. Accordingly, atomization is prescribed by injecting drops which have a characteristic size equal to the nozzle exit diameter. Example problems include the nearly homogeneous and inhomogeneous turbulent particle dispersion, and the non-evaporating, evaporating, and burning dense sprays. Comparison with experimental data will be discussed in detail.
Document ID
19920023014
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Chen, C. P.
(Alabama Univ. Huntsville., United States)
Kim, Y. M.
(Alabama Univ. Huntsville., United States)
Shang, H. M.
(Alabama Univ. Huntsville., United States)
Ziebarth, J. P.
(Alabama Univ. Huntsville., United States)
Wang, T. S.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1992
Publication Information
Publication: NASA. Goddard Space Flight Center, Tenth Workshop for Computational Fluid Dynamic Applications in Rocket Propulsion, Part 2
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
92N32258
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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