We investigate the stability and control of a plane, laminar jet impinging on a flat plate in a channel, a geometry used to cool down a hot wall with a cold air jet in many industrial configurations. The global stability analysis indicates that, even for a strong confinement, the two-dimensional (2-D) steady flow is unstable to three-dimensional (3-D), steady perturbations. In the simplest limit case where dilatation effects are neglected, we show that the development of the instability induces a significant spanwise modulation of the heat flux at the impacted wall. To control the leading global mode, we propose adjoint-based 3-D harmonic and 2-D steady forcing in the bulk or at the wall. We show for instance that the unstable mode is controllable using a spanwise uniform blowing at the upper wall, in a specific domain corresponding to the footprint of the upper recirculating bubble. These techniques are applied to a novel open-loop control, in which we introduce into the flow a small airfoil, modelled by the lift force it exerts on the flow.
%0 Journal Article
%1 meliga2011global
%A Meliga, Philippe
%A Chomaz, Jean-Marc
%D 2011
%J Theoretical and Computational Fluid Dynamics
%K 76d25-wakes-and-jets 76e09-stability-and-instability-of-nonparallel-flows
%P 179-193
%R 10.1007/s00162-010-0194-6
%T Global modes in a confined impinging jet : application to heat transfer and control
%U https://link.springer.com/article/10.1007%2Fs00162-010-0194-6
%V 25
%X We investigate the stability and control of a plane, laminar jet impinging on a flat plate in a channel, a geometry used to cool down a hot wall with a cold air jet in many industrial configurations. The global stability analysis indicates that, even for a strong confinement, the two-dimensional (2-D) steady flow is unstable to three-dimensional (3-D), steady perturbations. In the simplest limit case where dilatation effects are neglected, we show that the development of the instability induces a significant spanwise modulation of the heat flux at the impacted wall. To control the leading global mode, we propose adjoint-based 3-D harmonic and 2-D steady forcing in the bulk or at the wall. We show for instance that the unstable mode is controllable using a spanwise uniform blowing at the upper wall, in a specific domain corresponding to the footprint of the upper recirculating bubble. These techniques are applied to a novel open-loop control, in which we introduce into the flow a small airfoil, modelled by the lift force it exerts on the flow.
@article{meliga2011global,
abstract = {We investigate the stability and control of a plane, laminar jet impinging on a flat plate in a channel, a geometry used to cool down a hot wall with a cold air jet in many industrial configurations. The global stability analysis indicates that, even for a strong confinement, the two-dimensional (2-D) steady flow is unstable to three-dimensional (3-D), steady perturbations. In the simplest limit case where dilatation effects are neglected, we show that the development of the instability induces a significant spanwise modulation of the heat flux at the impacted wall. To control the leading global mode, we propose adjoint-based 3-D harmonic and 2-D steady forcing in the bulk or at the wall. We show for instance that the unstable mode is controllable using a spanwise uniform blowing at the upper wall, in a specific domain corresponding to the footprint of the upper recirculating bubble. These techniques are applied to a novel open-loop control, in which we introduce into the flow a small airfoil, modelled by the lift force it exerts on the flow.},
added-at = {2021-09-07T01:56:40.000+0200},
author = {Meliga, Philippe and Chomaz, Jean-Marc},
biburl = {https://www.bibsonomy.org/bibtex/2bf670afae8ffa0373a6233f5bcac34ab/gdmcbain},
doi = {10.1007/s00162-010-0194-6},
interhash = {8d66f4e1fabeb4d66642d33c8acde8f4},
intrahash = {bf670afae8ffa0373a6233f5bcac34ab},
journal = {Theoretical and Computational Fluid Dynamics},
keywords = {76d25-wakes-and-jets 76e09-stability-and-instability-of-nonparallel-flows},
pages = {179-193},
timestamp = {2021-09-20T18:59:04.000+0200},
title = {Global modes in a confined impinging jet : application to heat transfer and control},
url = {https://link.springer.com/article/10.1007%2Fs00162-010-0194-6},
volume = 25,
year = 2011
}