Linus Marstorp

Explicit algebraic subgrid stress models with application to rotating channel flow

New explicit subgrid stress models are proposed involving the strain rate and rotation rate tensor, which can account for rotation in a natural way. The new models are based on the same methodology ...

A stochastic subgrid model with application to turbulent flow and scalar mixing

A new computationally cheap stochastic Smagorinsky model which allows for backscatter of subgrid scale energy is proposed. The new model is applied in the large eddy simulation of decaying isotropi ...

Explicit Algebraic Subgrid Stress Models for Large Eddy Simulation

New explicit subgrid stress models have been developed which are based on the same methodology that leads to the EARSM formulation for RANS. The subgrid models involve the strain rate and rotation rate tensor, and can account for rotation in a natural way. A dynamic and a non-dynamic version are proposed. The non-dynamic version is a computationally cheap SGS model, whereas the dynamic version is more accurate. Large eddy simulations of rotating channel flow have been carried out in order to test the models. Comparison with the standard and dynamic Smagorinsky models shows that the explicit dependence on the system rotation improves the description of the mean velocity profiles and the Reynolds stresses at high rotation rates. Furthermore, large eddy simulations with the new models are less sensitive to the grid resolution.

Explicit Algebraic Subgrid Models for Large Eddy Simulation

The objective of this study is to develop models for the subgrid-scale (SGS) stress and the SGS scalar flux by applying the same kind of methodology that leads to the explicit algebraic Reynolds stress model, EARSM [2], and the explicit algebraic scalar flux model, EASFM [3], for RANS. The idea is that these new models can improve the description of the anisotropy compared to eddy viscosity models. Since the new models can include the effect of system rotation in a natural way they have a particular potential for rotating flows.

A stochastic SGS model with application to turbulent channel flow with a passive scalar

A new computationally inexpensive stochastic Smagorinsky model which allows for backscatter is proposed. The inclusion of stochastic backscatter is shown to improve some statistics of the passive scalar field in LES of fully developed channel flow.

Stochastic SGS modelling in homogeneous shear flow with passive scalars

A new stochastic Smagorinsky model for the subgrid stress and subgid scalar flux is proposed. The new model is applied in LES of rotating homogeneous shear flow, which is an excellent case for deve ...