#Define airfoil full#

The results show that the navigational speed that is in the inflow condition of the ducted propeller play important roles in the flow structure and underwater radiated noise. The frequency domain and directivity of sound pressure level at different sound field monitoring points are analyzed at four navigational speeds. Hydrodynamic noise are calculated by FWH equation based on the CFD results.

#Define airfoil full#

The full scale flow filed and hydro-acoustic sources of the propulsion system are simulated by Detached-Eddy computational fluid dynamics (CFD) method. The hybrid techniques based on the acoustic analogy theory are adopted in the present study to calculate the unsteady flow field and sound field characteristics of a ducted propeller.

Finally, the optimal CFD propeller is compared against a commercial propeller with the same diameter, pitch, and operational conditions, showing higher thrust and efficiency.ĭucted propeller is a kind of special propeller widely used in unmanned underwater vehicles, its flow characteristics and hydrodynamic noise are very important for marine environmental protection and equipment concealment. Wind tunnel tests were performed with printed propellers to conclude the feasibility of the entire routine and the differences between XFOIL and CFD optimal propellers. A case of study is carried out where the chord and pitch distributions are compared to minimal losses distribution from vortex theory. A structural model based on Euler-Bernoulli beam theory is employed and validated against Finite Element Analysis, while the impact of centrifugal forces is discussed. The coefficients for the rotational corrections are proposed from experimental data fitting. The aerodynamic data are corrected to account for compressibility, three-dimensional, viscous, and Reynolds number effects. A stall angle correction is estimated from experimental NACA 4-digits data and employed where convergence issues emerge. The propeller performance prediction tool employs a convergence improved Blade Element Momentum Theory fed by airfoil aerodynamic characteristics obtained from XFOIL and a validated OpenFOAM. A wide range of propeller parameters is considered in the optimization, including the geometry of the airfoil at each propeller section. The results demonstrate that the accuracy of the proposed parametric model satisfies the engineering requirements well, and a propeller with higher efficiency than the baseline propeller can be derived by settling the propeller optimization problem.Īn aero-structural algorithm to reduce the energy consumption of a propeller-driven aircraft is developed through a propeller design method coupled with a Particle Swarm Optimization (PSO). Also, non-dominated sorting genetic algorithm II is used in the applications of the propeller optimization problem. A hydrodynamic performance evaluation model is developed based on gene expression programming. The proposed parametric model is used for the representation and deformation of the propeller geometric model. In the propeller optimization problem, a common AU-series propeller is treated as the baseline propeller. Furthermore, a propeller optimization problem was addressed with the aid of the parametric model. 20 different hydrofoils and 5 types of well-known marine propellers are employed to detect the accuracy of the proposed parametric model. It involves eight parameters and five categories of spanwise parameter distributions, which are utilized for determining hydrofoil and blade shapes. This paper presents a novel parametric model of marine propellers based on Non-Uniform Rational B-Splines.