High numerical model

For the analysis heat and mass transfer in concrete samples at high temperatures, the numerical model has been developed. It describes concrete, as a porous multiphase system which at local level is in thermodynamic balance with body interstice, filled by liquid water and gas phase. The model allows researching the dynamic characteristics of diffusion in view of concrete matrix phase transitions, which was usually described by means of experiments. 

L= low, M = medium, H = high input data requirements. In general, numerical models have higher input data requirements and calibration needs, therefore, may better represent spatial resolution of a domain. Compartment models provide an optimal compromise (see Section 4.2). The level of effort is intuitively defined here. 

Kondo and co-workers have studied through-mask deposition in the convective regime experimentally for both low [141] and high [142] Peclet numbers. They have also developed a numerical model which incorporates fluid flow [143], Their Peclet number is defined in terms of the cavity depth and has the same form as Eq. (6.12). They considered the effects of cavity geometry as determined by aspect ratio and sidewall angle. 

Figure 5.7. Comparison of numerical modeling to high-speed video imaging of droplet trajectories in the spray during spray forming. Left, calculated droplet trajectories Right, high-speed video imaging of an actual spray. (Courtesy of Prof. Dr.-Ing. Klaus Bauckhage at University of Bremen, Germany.)...

Although several different system configurations have been simulated, the focus of this paper will be on the unsteady, compressible, multiphase flow in an axisymmetric ramjet combustor. After a brief discussion of the details of the geometry and the numerical model in the next section, a series of numerical simulations in which the physical complexity of the problem solved has been systematically increased are presented. For each case, the significance of the results for the combustion of high-energy fuels is elucidated. Finally, the overall accomplishments and the potential impact of the research for the simulation of other advanced chemical propulsion systems are discussed. 

For this reason, only highly reliable models coupled with accurate numerical routines such as those presented here are useful for the professional chemical/biological engineer. 

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