유동 간섭 효과를 고려한 Wing-sails 공력 최적 설계

다국어 초록 (Multilingual Abstract)

These day, an issues related with environments are becoming more pressing. We investigated potential next-generation vessel which makes use of the wing-sails to support existing fossil fuel-based propulsion system. The sailing-ship is a new concept eco-friendly vessel that uses the wind energy to produce additional thrust force by wing-sails above the hull. In this study, we focused on the aerodynamic analysis and design optimization of multiple wing-sails by varying the wind direction 15 degrees to 165 degrees. For the numerical analysis, we solved three dimensional compressible Navier-stokes equation with Spalart-Allmaras turbulent model. After the investigation of aerodynamic characteristics around wing-sails and the effect of flow interactions, we performed the design optimization of wing-sails by considering both single wing-sail and multiple wing-sails. In single wing-sail design, we found optimal value of deflection angle and flap length of single wing-sail to maximize the lift performance. In multiple wing-sails design, we carried out design optimization to find an optimal set-up of individual for each of the wing-sails that maximize total thrust of wing-sails. These optimal set-up include a deflection angle, deflection length and angle of attack of each wing-sails. Using a Kriging-based surrogate model and the derivative-free optimization method of genetic algorithms (GAs), we found the optimal set-up of the single and multiple wing-sails. The design optimization results showed that the total thrust of wing-sails has improved by 27~36% corresponding to the varying the wind directions.