Investigation of the Influence of Blocking Effect on the Aerodynamic and Hydrodynamic Characteristics of a Powered Aircraft Model

Abstract

This paper investigated the influence of blocking effect on the aerodynamic characteristics of a powered aircraft model by experimental and numerical methods. Firstly, the towing test were carried out in the bottom and front of the trailer. The experimental results showed that the darg and trim of two conditions were different, indicating that the blocking effect was obvious. RANS method, slidding mesh and overset grid were adopted in numerical simulation. The simulation of the wind field in the bottom and front of the trailer were carried out. And the numerical results were compared with the experimental results to verify the accuracy of numerical method adopted in this paper. The results showed that the wind speed in the bottom of the trailer was larger than that in the front of the trailer on average and there was stable speed increment interval when the wind filed simulation was conducted in the front and the bottom of the trailer without model. Then the hydrodynamic performance of the powered aircraft model in infinite domain, in the bottom of the trailer and in front of the trailer were carried out respectively. The aerodynamic downward moment was larger when the model was in the bottom, but the overall aerodynamic lift force of the model was similar under the two conditions. The heave amplitude was also similar under the two conditions, but the trim angle and the total drag was smaller when the model was in the bottom of the trailer.