Thermofluidics:
Heat Transfer and Convective Flows

The computational description of evaporation processes requires the calculation of the heat and mass transfer exchange rate over the liquid/gas interface. The most influential parameter for the exchange rates is the relative humidity of the gas phase. The highest relative humidity gradient occurs at temperature levels slightly below the boiling point. As a result, these temperatures have to be considered when computing the dispersed phase evaporation driven by temperature increase. more...


Turbulence Modeling:
Boundary Layers and Scale Transitioning

Thanks to numerous technical studies the physical law of periodic flow instability in fluid flows with high Reynolds numbers is well-known. The laminar character (stream lines positioned in laminar layers) is destroyed by perturbations, which diffuse from the wall through the complete flow domain. The change from a steady laminar stream to an unsteady turbulent flow is defined as transient.This transient behavior in turbulent flows is investigated by modeling the velocity correlations in the fluid. more...


Dispersed Flows:
Molecular Diffusion and Collision of Transonic Microflows

In the main field of research the frontiers of classical flow descriptions are investigated. High Knudsen numbers lead to a molecular, non-continuous fluid behavior. As a consequence, high Knudsen numbers (Kn) deny the description of a flow by a continuous approach and additional statistical models have to be defined. In this case, a quasi-continuous transport model for dispersed systems based on transport equations for statistical moments is used. more...


Computational Methods for Hypersonic Flows:
Shock Waves and Transonic Flow Regimes

When developing machines and facilities with optimization regarding fluid dynamic behavior, the form of the optimization tools results from the operating conditions of the studied flow (laminar, turbulent, incompressible, trans-sonic, hyper-sonic, molecular, continuous etc.). If mixed conditions are present, the interactions between the sub-models has to be investigated and modeled through coupled transport equations. more...


Electrodynamics:
Emission, Ionization and Thermo-electric Thruster Systems

When the difference in electric potential between electrodes with different charge is high enough, an electric discharge through the fluid medium separating the electrodes occurs. The resulting electric flux is associated with a local motion of electrons, the only mobile charge carrier inside the solid electrodes. As a result from the motion of electrons and the collisions and resistance forces inside the conducting electrodes, a local temperature increase occurs. more...


Magneto-Fluid Dynamics:
Plasma Modelling and Astrophysical Hydrodynamics

One of the most amazing applications of magneto fluid dynamics are astrophysical approximations. High temperatures are responsible for fusion and ionization processes in space. Furthermore, the motion of charged particles in space is part of its astrophysical description. The motion of charged particles near planets with a magnetic core or inside accretion discs in the environment of a black hole is the result from attaching forces of other particles and is influenced by electric and magnetic fields. more...