1,721,018 research outputs found
Trapped Vortex Optimal Control by Suction and Blowing at the Wall
No full textEUROPEAN JOURNAL OF MECHANICS / B FLUIDS, 200
IMPLICIT RELAXED ALL MACH NUMBER SCHEMES FOR GASES AND COMPRESSIBLE MATERIALS
No full textWe present an implicit relaxation scheme for the simulation of compressible flows in all Mach number regimes based on a Jin–Xin relaxation approach. The main features of the proposed scheme lie in its simplicity and effectiveness. Thanks to the linearity of the flux in the relaxation system, the time semidiscrete scheme can be reformulated in linear decoupled elliptic equations resulting in the same number of unknowns as in the original system. To obtain the correct numerical diffusion in all Mach number regimes, a convex combination of upwind and centered fluxes is applied. The numerical scheme is validated by applying it on a model for nonlinear elasticity. Simulations of gas and fluid flows, as well as deformations of compressible solids are carried out to assess the performance of the numerical scheme in accurately approximating material waves in different Mach regimes
Feedback control by low-order modelling of the laminar flow past a bluff body
No full textIn this work a two-dimensional laminar flow past a square cylinder is considered.
Actuators placed on the cylinder enable active control by blowing and suction.
Proportional feedback control is then applied using velocity measurements taken
in the cylinder wake. Projection onto an empirical subspace is combined with a
calibration technique to build a low-order model of the incompressible Navier–Stokes
equations. This model is used within an optimization method to determine a set of
feedback gains which reduces the unsteadiness of the wake at Re =150. The resulting
controlled flows are further characterized by computing the critical Reynolds numbers
for the onset of the vortex shedding instability
The continuous adjoint to the Navier-Stokes equations and its application to hybrid evolutionary airfoil design
No full text- …
