Wall Modeling Techniques for Large-Eddy Simulation
Abstract
In the LEE of high Reynolds number wall-bounded flows, wall modeling is needed to alleviate the severe near-wall resolution requirement. Simple algebraic models such as the instantaneous log-law are inadequate for predicting complex flows with strong pressure gradients and separation. We have explored two classes of wall models: those based on the turbulent boundary-layer (TBL) equations and those based on control theory. Recent application of the TBL equation model to LEE of the flow over a cylinder at super-critical Reynolds number is discussed. The emphasis of the report is on control based wall modeling, in which sub-optimal control strategy is used to find the wall stresses that will force the outer LEE toward a target profile. Results from channel-flow simulation indicate that in order to obtain the correct mean velocity profile (the log law), the wall stresses must not only model the physics but also compensate for numerical and SGS modeling errors. The data generated by this sub-optimal control strategy are then used to derive a linear stochastic estimate model. The mathematical formulation and issues of key importance in control-based wall modeling are detailed. Efforts towards a predictive and inexpensive wall model in the control framework are detailed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2002
- Accession Number
- ADA410335
Entities
People
- Franck Nicoud
- Jeffrey Baggett
- Jeremy Templeton
- Meng Wang
- Parviz Moin
Organizations
- Stanford University