Bore-Rider Design of Cone-Flair-Cylinder Projectiles for Hypersonic Boundary Layer Transition Studies

One approach to study hypersonic boundary layer transition on a conical geometry is to launch the model with a two-stage light gas gun. However, the attitude and integrity of cone projectiles launched with sabots depend on the interaction between the components during the separation and the specific design of the sabot. A new approach for launching a conical forebody in a two-stage light gas gun is presented in this work, which uses a bore-rider design. The bore-rider design for the cone-flair-cylinder projectiles is evaluated for its stability and attitude in hypersonic flight conditions. Cones with half-angles of 5, 10, 15, and 20 degrees were flown at a flight speed of approximately 2000 m/s. The stability and aerodynamic characteristics of the projectiles are qualitatively analyzed using high-speed schlieren images and modeled using the CFD package Eilmer. In addition to the analysis on the stability of the projectiles, a detailed discussion on the design of the bore-rider approach is also included.