Development and Validation of Conceptual Design Framework for a Mid-Size Turbo-Prop Transport

Abstract

concurrent with the growth of the airline industry. South Korea is in the process of designing and developing its own mid-size turboprop transport to keep pace with the international trend. For that purpose, we developed an in-house sizing program as a conceptual design tool and increased its accuracy by integrating mid- and high-fidelity analyses into the sizing process. The reliability of the conceptual design framework was verified by analyzing the mission profile of an existing turbo-prop aircraft. Moreover, a multi-level design framework was developed that sequentially employs the conceptual design framework for the sizing and detailed design for adjoint-based optimization. First, gradient-free optimization to maximize the cruise performance was carried out using the conceptual design framework with a limited number of geometric design variables to change the wing planform. All the mission requirements were well-satisfied because they were imposed on the design process as the explicit form of the constraints. Second, gradient-based optimization was carried out to provide further details for the configuration optimized at the first level. A large number of design variables were included in this design level to minimize drag. By iterating these two levels, a more comprehensive design could be achieved with a large number of design variables while taking into account the entire mission from take-off to landing. As a result, about 5~6% increase in L/D based on the inviscid drag was obtained from the planform design, and the sequential section design results in an additional 1.1%, indicating that the current design framework is successful.