*Bijan Mohammadi and Olivier Pironneau*

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199546909
- eISBN:
- 9780191720482
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199546909.003.0011
- Subject:
- Mathematics, Mathematical Physics

This chapter presents applications of shape optimization algorithms to cases where the flow is unsteady for rigid and elastic bodies, and shows that control and OSD problems are particular cases of a ...
More

This chapter presents applications of shape optimization algorithms to cases where the flow is unsteady for rigid and elastic bodies, and shows that control and OSD problems are particular cases of a general approach. Closed loop control algorithms are presented together with an analogy with dynamical systems. The chapter starts with model problems for rigid and elastic objects. In multi-model configurations, coupling strategies have been discussed and low complexity models introduced.Less

This chapter presents applications of shape optimization algorithms to cases where the flow is unsteady for rigid and elastic bodies, and shows that control and OSD problems are particular cases of a general approach. Closed loop control algorithms are presented together with an analogy with dynamical systems. The chapter starts with model problems for rigid and elastic objects. In multi-model configurations, coupling strategies have been discussed and low complexity models introduced.

*Bijan Mohammadi and Olivier Pironneau*

- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199546909
- eISBN:
- 9780191720482
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199546909.003.0003
- Subject:
- Mathematics, Mathematical Physics

This chapter describes the governing equations considered throughout the book. The equations of fluid dynamics are recalled, together with the k-epsilon turbulence model, which is used later on for ...
More

This chapter describes the governing equations considered throughout the book. The equations of fluid dynamics are recalled, together with the k-epsilon turbulence model, which is used later on for high Reynolds number flows when the topology of the answer is not known. The fundamental equations of fluid dynamics are recalled; this is because applied OSD for fluids requires a good understanding of the state equation: Euler and Navier–Stokes equations in this case, with and without turbulence models together with the inviscid and/or incompressible limits. The chapter recalls wall-laws also used for OSD as low complexity models. By wall-laws domain decomposition with a reduced dimension model near the wall is understood. In other words, there is no universal wall-laws and when using a wall-function, it needs to be compatible with the model used far from the wall. Large eddy simulation is giving a new life to the wall-functions especially to simulate high-Reynolds external flows.Less

This chapter describes the governing equations considered throughout the book. The equations of fluid dynamics are recalled, together with the k-epsilon turbulence model, which is used later on for high Reynolds number flows when the topology of the answer is not known. The fundamental equations of fluid dynamics are recalled; this is because applied OSD for fluids requires a good understanding of the state equation: Euler and Navier–Stokes equations in this case, with and without turbulence models together with the inviscid and/or incompressible limits. The chapter recalls wall-laws also used for OSD as low complexity models. By wall-laws domain decomposition with a reduced dimension model near the wall is understood. In other words, there is no universal wall-laws and when using a wall-function, it needs to be compatible with the model used far from the wall. Large eddy simulation is giving a new life to the wall-functions especially to simulate high-Reynolds external flows.