Optimal Aft End Distorted Fin Model Using Response Surface Method

Abstract

In wind-tunnel testing of bomb or missile-type models, aft end geometry distortion may become necessary when a model is tested by using a sting support system. When the diameter of the model base is increased, the exposed tail fin area is reduced to result in aerodynamic data alteration. In the present work, various tests are conducted on an MK-82 bomb model with base diameter and exposed tail fin area variations. The tests use techniques involving design of experiments and response surface modeling. The effects of the model base geometry modifications on the aerodynamic characteristics are investigated. Experimental design optimization is then performed on the basis of three design factors: the base diameter, the extended tail fin area, and the freestream velocity. The experimental results show that the altered aerodynamic characteristics due to aft end model distortion can be minimized by changing the tail fin geometry on the basis of the regression model.