Turbulent transport phenomena in three-dimensional side-dump ramjet combustors

1989 ◽  
Vol 32 (11) ◽  
pp. 2113-2125 ◽  
Author(s):  
Y.H. Hwang ◽  
Y.H. Hung
2007 ◽  
Vol 22 (1) ◽  
pp. 1-9
Author(s):  
Umberto Rizza ◽  
Jonas C. Carvalho ◽  
Davidson M. Moreira ◽  
Marcelo R. Moraes ◽  
Antônio G. Goulart

In this article is carried out a comparison between Lagrangian and Eulerian modelling of the turbulent transport of pollutants within the Planetary Boundary Layer (PBL). The Lagrangian model is based on a three-dimensional form of the Langevin equation for the random velocity. The Eulerian analytical model is based on a discretization of the PBL in N sub-layers; in each of the sub-layers the advection-diffusion equation is solved by the Laplace transform technique. In the Eulerian numerical model the advective terms are solved using the cubic spline method while a Crank-Nicholson scheme is used for the diffusive terms. The models use a turbulence parameterization that considers a spectrum model, which is given by a linear superposition of the buoyancy and mechanical effects. Observed ground-level concentrations measured in a dispersion field experiment are used to evaluate the simulations.


2008 ◽  
Vol 07 (02n03) ◽  
pp. 103-112 ◽  
Author(s):  
A. SAKURAI ◽  
S. MARUYAMA ◽  
A. KOMIYA ◽  
K. MIYAZAKI

The Discrete Ordinates Radiation Element Method (DOREM), which is radiative transfer code, is applied for solving phonon transport of nano/microscale materials. The DOREM allows phonon simulation with multi-dimensional complex geometries. The objective of this study is to apply the DOREM to the nano/microstructured materials. It is confirmed that significant changes of the heat transport phenomena with different characteristic length scales and geometries are observed. This study also discusses further variations for understanding of heat transport mechanisms.


2014 ◽  
Vol 2014 (0) ◽  
pp. _1407-1_-_1407-2_
Author(s):  
Katsuhito KOZAWA ◽  
Hiroki YOKOE ◽  
Tadayoshi SUGIMURA ◽  
Yoshihiro TAKI

1987 ◽  
Vol 134 (10) ◽  
pp. 2552-2559 ◽  
Author(s):  
S. Rhee ◽  
J. Szekely ◽  
O. J. Ilegbusi

1975 ◽  
Vol 97 (2) ◽  
pp. 238-243 ◽  
Author(s):  
H. Ramm ◽  
K. Johannsen

A theoretical method based on a phenomenological turbulence model has been applied to evaluate turbulent transport properties for liquid-metal heat transfer in bare equilateral triangular rod bundles. Results obtained for local distributions of thermal eddy diffusivity in the various directions are presented in terms of correlations. From a subsequent solution of the three-dimensional heat transfer problem between two characteristic interior subchannels under conditions characteristic for tracer-type mixing experiments, integral thermal mixing coefficients and thermal length scales have been evaluated. Results demonstrate that the basic concept of subchannel analysis treating molecular conduction and turbulent transport independently of each other tends to underestimate intersubchannel transport. The uncertainties which are involved in principal assumptions of the turbulence-model as well as in the available empirical results are discussed in some detail.


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