Preliminary Mean-Line Design of a Single-Stage Axial Turbine for RC Turbojet

Project Overview

Small gas turbine engines for RC aircraft present unique turbomachinery design challenges due to their scale, low Reynolds numbers, and tight manufacturing tolerances, particularly for the high-temperature, high-speed turbine. This project focused on developing a preliminary design for the single-stage axial-flow turbine of a medium-class RC turbojet engine, which is critical for overall engine performance and mechanical integrity. A custom Python solver was developed to conduct a comprehensive thermodynamic cycle analysis, establishing mass flow, fuel consumption, and station conditions, followed by a detailed mean-line aerodynamic design of the turbine stage. This methodology included determining velocity triangles, annulus sizing, blade count, and a first-order mechanical stress check. The design targeted a static sea-level thrust of 130 N, consistent with hobby-grade turbojets. The resulting preliminary design successfully defined the turbine's geometry and operating parameters, demonstrating a viable solution for the specified performance envelope and providing insights into off-design behavior.