Flap efficiency of a delta wing with an external store using an Euler code for small disturbances

The results of a numerical investigation on flap efficiency of a delta wing with an external store attached are discussed. The wing has ail inboard and an outboard flap. The store is attached to the wing on the lower surface in the area of the outboard flap. For this geometry a structured multiblock mesh has been generated and elliptically smoothed. Numerical investigations are carried out with an Euler code using a small disturbance solver (FLM-SDEu) and an unsteady solver (FLM-Eu). The first assumes that the unsteady disturbances are small in comparison to the overall steady mean flow [ 1] [2], the latter is only used for comparison to FLM-SDEu. The small disturbance code reduces the calculation time significantly and the results obtained show good conformity with the results from the unsteady solver [3] [4].