Principles of the software

Physical premises:
- viscous incompressible fluid - air, water, overheated steam, mixture of wet steam and air
- 3D one phase turbulent flow
- physical reality as described by equations of transport of momentum, energy, concentration and continuity
- the system of equations is closed by relation for turbulent viscosity or by equations describing the k-epsilon model of turbulence

Numerical solution:
- discretized equations are solved by the explicit/implicit method of finite volumes in the computational mesh formed by irregular hexahedrons
- method of solution: an original method developed by I. Zuber - an implicit solution of the second order of accuracy, time step iteration, time marching method (the aim of iterations is to reach steady resulting flow fields)
- the numerical solution is conservative from the point of view of the heat, momentum and energy transport
- equations for the physical variables are solved (velocity components, pressure, temperature and concentration)
- the flow through the tube bundle has been modeled as the flow through the porous area with enlarged aerodynamic resistance and heat-transfer coefficient dependent on the physical state of the flow
- standard boundary conditions:
impermeable walls
velocity profile, temperature and k-values are known in input area
static pressure profile is known in output area

Software characteristics:
- the software core is universal, the change of the task is done only by changing input data
- universal user environment
- dialogue preprocessing with possibility of supplementing the input data changes
- graphical generation of computational mesh
- dialog communication and graphic check of the time marching process
- presentation of results by means of original graphic outputs in chosen areas
- programming languages: Fortran, C++

Some examples of usage of the code:
- calculation of flow fields within the stator of the reversible axial fan by ZVVZ Milevsko for aeration of traffic tunnels
- calculations of the flow within an axial compressor stator vane channel solved in the scope of a grant of the Czech grant agency
peripheral section : velocities and pressure
axial section : velocities and pressure
- cooperation with the Centre of aeronautical research of Czech Technical University in Prague supported by the Czech grant agency concerned the research in the substance of turbulence
- optimization of designs of large condensers of power station steam turbines in collaboration with Skoda Energo company, e.g. design of reconstruction of the condensers in Dukovany nuclear power station
cross-section : velocities and pressure
- calculations of heaters for power station in China supplied by Skoda Energo Company
longitudinal section : velocities, temperature and pressure
- computations of velocity and pressure fields in various forms of input area of chimneys on the Melnik III and Tusimice I Power stations for different working conditions
cross-section : velocities and pressure
longitudinal section : velocities and pressure