Current capabilities and challenges of NDARC and SUAVE for eVTOL aircraft design and analysis

This paper compares and contrasts the application of two conceptual methods for the design and analysis of eVTOL aircraft. The starting point is a widely publicized reference design, the Kitty Hawk Cora, modeled using publicly available information. Using the two tools (NDARC and SUAVE), estimates of weight and performance of the aircraft for the same reference mission are made, highlighting areas of uncertainty based on differences in the observed results, with distinctions between design assumptions and modeling differences emphasized. Trade studies of gross takeoff weight vs. rotor radius and wingspan were performed to focus on the different sensitivities the models possess. For the initial designs, there was some agreement in overall gross takeoff weight despite different estimates for aerodynamic performance and component weights. While agreement was shown in terms of how rotor radius trades, the wingspan sweep showed opposing trends between these two codes. This paper details the reasons behind these disagreements and discusses particular disciplines that require closer scrutiny and further development using higher fidelity methods.