Zobrazeno 1 - 10
of 39
pro vyhledávání: '"Sharma, Ati"'
We propose a novel framework for approximating the statistical properties of turbulent flows by combining variational methods for the search of unstable periodic orbits with resolvent analysis for dimensionality reduction. Traditional approaches rely
Externí odkaz:
http://arxiv.org/abs/2408.13120
The sensitivity of long-time averages of a hyperbolic chaotic system to parameter perturbations can be determined using the shadowing direction, the uniformly-bounded-in-time solution of the sensitivity equations. Although its existence is formally g
Externí odkaz:
http://arxiv.org/abs/1806.02077
A family of compressible exact periodic solutions is reported for the first time in an open cavity flow setup. These are found using a novel framework which permits the computation of such solutions in an arbitrary complex geometry. The periodic orbi
Externí odkaz:
http://arxiv.org/abs/1710.03060
Autor:
Ahmed, Muhammad Arslan, Sharma, Ati
Publikováno v:
Phys. Rev. E (2020)
New equilibrium solution branches for plane Couette flow are reported which add to the inventory of known solution branches. The exact solutions are found by projecting known equilibria onto the resolvent modes of McKeon & Sharma (J. Fl. Mech., vol.
Externí odkaz:
http://arxiv.org/abs/1706.05312
Recent progress indicates that highly symmetric recurring solutions of the Navier-Stokes equations, such as equilibria and periodic orbits, provide a skeleton for turbulence dynamics in state-space. Many of these solutions have been found for flat-wa
Externí odkaz:
http://arxiv.org/abs/1612.07723
Publikováno v:
Phys. Rev. Fluids 1, 032402 (2016)
The relationship between Koopman mode decomposition, resolvent mode decomposition and exact invariant solutions of the Navier-Stokes equations is clarified. The correspondence rests upon the invariance of the system operators under symmetry operation
Externí odkaz:
http://arxiv.org/abs/1603.08378
A novel adjoint-based framework oriented to optimal flow control in compressible direct numerical simulations is presented. Also, a new formulation of the adjoint characteristic boundary conditions is introduced, which enhances the stability of the a
Externí odkaz:
http://arxiv.org/abs/1603.05887
This paper describes a robust linear time-invariant output-feedback control strategy to reduce turbulent fluctuations, and therefore skin-friction drag, in wall-bounded turbulent fluid flows, that nonetheless gives performance guarantees in the nonli
Externí odkaz:
http://arxiv.org/abs/1602.07149
Autor:
Sharma, Ati S., Moarref, Rashad, McKeon, Beverley J., Park, Jae Sung, Graham, Michael D., Willis, Ashley P.
Publikováno v:
Phys. Rev. E 93, 021102 (2016)
We report that many exact invariant solutions of the Navier-Stokes equations for both pipe and channel flows are well represented by just few modes of the model of McKeon & Sharma J. Fl. Mech. 658, 356 (2010). This model provides modes that act as a
Externí odkaz:
http://arxiv.org/abs/1503.01701
Publikováno v:
Journal of Fluid Mechanics, Vol. 769, 2015, pp. 687-722
This paper addresses the problem of obtaining low-order models of fluid flows for the purpose of designing robust feedback controllers. This is challenging since whilst many flows are governed by a set of nonlinear, partial differential-algebraic equ
Externí odkaz:
http://arxiv.org/abs/1502.02154