We study the linear stability of high speed flows on compression ramps where experimental and computational evidence suggests presence of flow characteristics that deviate from the two-dimensional laminar behavior. Due to the presence of separated boundary layers, a global stability analysis framework is necessitated. To understand the stability of high speed flows on realistic geometries, we develop an unstructured finite-volume based discretization for the compressible Navier-Stokes equations linearized in conserved variables. We work with conserved variables because their fluxes are continuous across shocks and the linearized equations lend themselves to a discretization employed to compute the base flow-field. In this paper, we focus on obtaining the eigensolutions that describe the late-time perturbation dynamics of the linear system. After verifying the solver with several flow-cases reported in literature, we solve the eigenvalue problem that describes the modal growth of spanwise harmonic linear perturbations in a laminar supersonic flow on a compression ramp. We compare spanwise striations observed in experimental wall tem-perature measurements to the asymptotically unstable perturbations obtained from the biglobal analysis.
|Original language||English (US)|
|Title of host publication||47th AIAA Fluid Dynamics Conference, 2017|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|State||Published - 2017|
|Event||47th AIAA Fluid Dynamics Conference, 2017 - Denver, United States|
Duration: Jun 5 2017 → Jun 9 2017
|Name||47th AIAA Fluid Dynamics Conference, 2017|
|Other||47th AIAA Fluid Dynamics Conference, 2017|
|Period||6/5/17 → 6/9/17|
Bibliographical noteFunding Information:
This work was sponsored by Air Force Office of Scientific Research under grant number FA9550-12-1-0064 and Department of Energy/National Nuclear Security Administration Award number DE-NA0002382. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the funding agencies or the U.S. Government.