This thesis presents the design of two test sections, one annular and one rectilinear, to facilitate the study of ducted flows at high subsonic Mach numbers on the Carleton high-speed wind-tunnel. The structural performance of the two designs was evaluated using finite element tools and were deemed compliant with provincial pressure-vessel regulatory requirements. Both designs benefit from lighter-weight materials and a greater degree of modularity than existing high-speed test sections. The aerodynamic performance of an annular-flow air-supply system was evaluated using a transient, one dimensional algorithm. The annular flow path provides a steady Mach number flow in the range of 0.3 to 0.8 at the test section discharge, with minimal pressure loss to achieve minimum run times of 25-30 seconds on a blow-down type wind-tunnel. The present study also evaluates the flow seeding performance of a seed injection system on the annular-flow air-supply system for particle image velocimetry measurements.