Presenter Information

Josiah D. Elliott


Mechanical and Aerospace Engineering


Aerospace Engineering

Research Advisor

Finaish, Fathi

Advisor's Department

Mechanical and Aerospace Engineering


Laminar Separation Bubbles (LSBs) are regions of separated flow that start near the leading edge of an airfoil and reattach further down the airfoil surface. These regions of separation can appear at low angles of attack and can grow significantly as the angle of attack is increased heavily influencing the flow characteristics over the airfoil. Research on this topic is driven by the supersonic business jet industry which has a particular interest in this type of research due to performance requirements in both the subsonic and supersonic flight regimes. This manuscript is focused on the flow developments near the sharp leading edge of supersonic airfoils and their influence on aerodynamic performance at low subsonic speeds. Computational Fluid Dynamics was utilized to show how LSB formation, size, and shape are dependent on the turbulence model chosen and the level of free-stream turbulence present in the flow. Two turbulence models were investigated, the Spalart-Allmaras and the Menter's SST. The LSB modeled by the Spalart-Allmaras turbulence model was consistently longer than the LSB modeled by the Menter's SST turbulence model. Both models verified the LSB dependence on the Reynolds and Mach number of the flow.

Presentation Type

Oral Presentation

Document Type


Presentation Date