High Speed Working Group

Lead: Kirk Brouwer

Objectives

  • Assess state of the art coupled FSI tools (coupled: structural dynamics + unsteady aerodynamics) in a predictive manner for high speed applications involving shock-wave boundary-layer interactions (SBLI)
  • Develop guidelines and metrics for coupling frequency to characterize degree of non-linear interaction
  • Define degree of SBLI and structural dynamic characteristics that require different analysis methods, model fidelity, grid resolution and treatment, temporal resolution, etc.
  • Identify gaps in current high-speed FSI experiments to provide feedback for future experiments to get better agreement between test and analysis

Background

  • High speed vehicles encounter complex flow physics, including turbulent fluctuations within the boundary layer, SBLI, and intense three-dimensionality that produce extreme aerodynamic loading conditions that directly impact the structure.
  • High-speed conditions are particularly challenging for computational tools because the coupling between the extreme environmental loads associated with high-speed flows and nonlinear structures drives unanticipated responses that are path-dependent and evolve over long durations
  • Closing the design loop for reusable high-speed vehicles requires a more accurate prediction of the environments and structural response to reduce conservatism

AFRL/SSC RC-19 Clamped Thin Panel

  • Representative of metallic skin panel for reusable hypersonic vehicle
  • No SBLI and attached SBLI generated by 4° wedge
    • No shock impingement: Periodic post-flutter response (baseline)
    • No shock impingement: Chaotic post-flutter response (optional)
    • Attached SBLI (4° wedge): periodic response (optional)
  • Conditions:Mach 1.92 ± 0.02 (air)
    • T0 = 295.95 ± 2.25 K
    • P0 = 345.92 ± 1.12 kPa

UNSW HyMAX Cantilever Plate

  • Representative of a control surface on a high-speed vehicle
  • Shock impingement on 2 mm thin aluminum panel, 130 x 80 mm cantilevered from rigid forebody
  • Fixed wedge angles (2 and 10°)
    • 2 degree case is laminar (mandatory)
    • 10 degree case is transitional (optional)
    • Oscillating wedge (optional)
  • Conditions: Mach = 5.8 ± 0.06 (air)
    • T0 = 580 ± 30 K, P0 ± 40 kPa
    • Tw = 300 ± 2 K

AFRL/SSC RC-19 Clamped Thin Panel Configuration

UNSW HyMAX Configuration

Structural response is 1st mode-dominated

Key Metrics

  • Post-processed DIC displacement
  • Power spectral density and oscillation amplitude at selected locations
HyMAX Aero Data
  • PSP -> surface pressure
  • SBLI location and footprint (size and location of separation bubble).
  • Pressure transducer time history near the trailing edge for validation.
Structural Response Data
  • Oscillation/time history of the cantilever plate.
  • Schlieren -> image tracking for vertical displacement.
  • Laser line scanner -> 100 points along the centerline of the plate.