Countergradient momentum flux in the presence of rolls in the atmospheric boundary layer

In the atmospheric boundary layer, when surface heat flux is small and mean wind shear is strong, horizontal convective rolls that are elongated along the wind shear are formed. This study attempts to explain the asymmetry of rolls in terms of turbulence using large-eddy simulations. A pressure gradient in the north-south y direction is applied,...

Approximate basis and a priori closure models for energy-conserving reduced order modeling of fluid flows

Model order reduction (MOR) has been a field of active research in the past twenty years, more recently also in fluid dynamics. The main advantage of MOR is computational cost reduction, which, along with equally important accuracy, constitute main objective in the MOR community.<br/>A main ongoing issue is that data volumes in fluid flow...

Simulation of Two-Dimensional Steady State Boundary Layers Applied to Nonideal Gas Flows

Organic Rankine Cycle (ORC) Power Plants can be of greatimportance in the energy transition as they are suitable for converting wasteheat to power and can utilize renewable energy for their operation. To improvethe efficiency of ORC Power Plants, the physical phenomena inside thesemachines must be understood....

Development of the Generalised Hybrid Turbulence Model for RANS simulations

Turbulence plays an important role in a broad range of engineering applications. In the industry RANS simulations are a common method for predicting turbulent flow. A broad range of RANS turbulence models have been developed over the past decades. For the assessment of complex three-dimensional flow fields Reynolds Stress Transport Models are a...