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The air flow field of ship was simulated by using computational fluid dynamics technology to analyze its prime characteristics with reasonable accuracy. The different results of Reynolds-Averaged Navier-Stokes (RANS) method and Detached Eddy Simulation (DES) were compared, and the calculation traits of these methods were discussed. The results show that the air flow field of ship is unsteady. The accuracy of RANS simulation is insufficient for capturing this unsteady phenomenon. However, DES can catch this with better accuracy and expresses a comparatively great conformity with experimental data. Then, the aircraft carrier's flow field was calculated by DES. The characteristics of vortexes and velocity fluctuation on the ideal landing track were discussed in different wind directions. Those simulations indicate that there are complicated vortexes produced by blunt edges of the island and deck in the flow field. Those vortexes interact and mainly exist in the rear of flight deck and its adjacent air wake. Moreover, they cause a conspicuous and periodical velocity fluctuation on the ideal landing track as time goes on.

In order to improve the design accuracy of the blade design method of a ducted fan based on the blade element momentum theory, the design was modified by the CFD calculation with higher accuracy to propose an integrated and efficient design method for the rotor and stator. Firstly, a fast blade design method for the ducted fan was established based on the blade element momentum theory, and the initial design of the rotor and stator was carried out. Then, the performance of the designed ducted fan was calculated by the CFD method, and the rotor and stator were modified and redesigned according to the CFD results. Such continuous iterations finally made the design results basically consistent with the CFD results so as to improve the design accuracy. The blade design of different ducted fans shows that the unsteady CFD method based on the sliding mesh has higher accuracy and applicability than the MRF method, and the efficient blade design method established in this paper can meet the thrust demand with a small amount of the CFD modification. The thrust design accuracy of the ducted fan was increased by 11.362%, and the torque design accuracy was increased by 8.141%.

The efficiency and accuracy of numerical simulation on power unit is the key to study the relevant aerodynamic layout with multiple rotating power units. However, the numerical simulation of the power unit using real geometry all faces the problem of low solution efficiency. Taking the rotor hovering state as an example, the real blade was firstly simplified and replaced by a thin mesh disk to establish the effective momentum source method. Then, using fan-shaped mesh region that changes with time to replace real blade and simulate the rotation, the unsteady momentum source method which could get the revolution of tip vortex was proposed. The results show that the momentum source method with the input of accurate blade force distribution can simulate rotor wake better, and the influence that blade geometry acts on wake mainly reflects in the blade force distribution. In addition, the unsteady momentum source method can simulate the revolution of tip vortex, and its consumptions of computing resources and calculation time are only about 1/8 of the unsteady numerical simulation based on the real geometry.