Application of a versatile data structure in computational fluid dynamics.
Oanta, Emil ; Barhalescu, Mihaela ; Sabau, Adrian 等
The paper presents applications of the matrix data structure in the
computational fluid dynamics field. This data structure was conceived in
order to have an instrument which integrates the matrix based approaches
in science and to overcome some information technology constraints.
Several libraries were developed in order to solve general problems,
such as: numerical methods, graphical representations, interfaces
between programming languages, etc. The numerical method employed to
solve the computational fluid dynamics problems was the finite
difference method, based on the aforementioned matrix data processing technique. Several CFD problems were solved and the original software
applications were important instruments to understand, to study and to
experiment the numerical aspects in this field of science. Key words:
data structure, software architecture, CFD
1. INTRODUCTION
Apart from the research studies dedicated to a narrow topic which
require experimental (Barhalescu, 2000), (Dumitrache, 2000), (Sabau,
2007) or numerical models (Oanta, 2007, b), (Oanta & al., 2007 a),
the complex problems require modern computer based instruments. Because
of the wide range of complex problems, these instruments cannot be
general, the development of dedicated and original software solutions
being the most appropriate approach. From this standpoint, the design of
a fluid dynamics original software requires a dedicated software which
may be adapted in order to offer a large volume of relevant information
regarding the problem in question.
2. GENERAL FEATURES OF THE CFD APPLICATION TO BE DESIGNED
The aim of the study is to implement different fluid flow models in
order to conclude regarding the accuracy of the model, boundary
conditions and implementation know how, flexibility and limitations of
the original software to be created.
The application to be implemented has both analytic and numeric
features. It is strongly parameterized in order to allow the researcher
to study different aspects of the phenomenon.
There must be noticed two classes of general requirements employed
in the design of a specialized software, like the previously mentioned
fluid dynamics application: general requirements and specific features
(figure 1).
[FIGURE 1 OMITTED]
3. FLUID DYNAMICS PROBLEMS APPROACHED
Several fluid dynamics problems were studied and the according
software instruments were implemented.
The first problem solved was to ascertain the influence of the grid
on the numerical modeling of the unsteady flow in marine diesel engines,
figure 2, (Dinescu & Oanta, 1998).
Another research study was dedicated to the problem of the 3D flow,
(Dinescu & Oanta, 1999). The application solved the flow problem
inside a complex shaped manifold, figure 3 and 4.
In order to have a high degree of confidence regarding the output
data, the sources of errors and instability were identified and studied,
being developed the according software instrument figure 5.
[FIGURE 2 OMITTED]
[FIGURE 3 OMITTED]
[FIGURE 4 OMITTED]
[FIGURE 5 OMITTED]
The original software instruments have implicit limitations which
are related to the numerical method employed, to the finite difference
method and to the basic hypotheses employed in this class of
computational fluid dynamics problems.
As a future research direction, one can study the way how the
nowadays powerful computers may be used to implement a software which
solves a CFD problem, (Nicolescu et al., 1999).
4. CONCLUSION
The libraries created to handle matrices in a facile way, (Oanta
& Nicolescu, 1999), were extensively used to develop software
applications in several fields of science (Oanta, 2001), (Oanta, 2009)
being a method to attain knowledge and to access an upper level of
understanding (Oanta & Nicolescu, 2004).
In CFD, the matrix-handling based original software instruments
offered the opportunity to study all the influences of the large number
of parameters of the model. Being a study dedicated to a narrow topic,
there could not be developed libraries which can be reused in other
fields of science. Moreover, the model and the software used embedded
numerical methods, i.e. the finite difference method.
Several aspects of the software solutions, starting with the
architecture of the application up to the method to handle the errors,
proved to be innovative, being acknowledged by the experienced CFD
analysts who used it in important CFD software developing companies.
Visualization of the results was a constant concern along the
years, at present being created modern software instruments dedicated to
this purpose (Oanta, 2007, a).
5. ACKNOWLEDGEMENT
The inspiring environment of the paper is the technological update
acquired in the framework of the "Computer Aided Advanced Studies
in Applied Elasticity from an Interdisciplinary Perspective" ID1223
scientific research project, under the supervision of the National
University Research Council (CNCSIS), Romania (Oanta & al., 2007 b).
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