Numerical investigation of the effect of intake integration at transonic speeds on the DLR-F17E UCAV model for the TWG

Abstract

A numerical investigation comparing the flow around the DLR-F17E geometry, a UCAV model at 1:20.5 scale, with and without an engine intake is resented. The through-flow ducts consisted of an intake through the top surface of the model connected to an internal duct system with two exits near the back of the model on the top side. Computations were performed at Mach numbers M=0.50 and M=0.75 and the differences between the flow around the two geometries investigated. A multiblock grid approach allowed pointwise differences to be taken between the two flow fields around the two geometries, and for all grids on the wings to be pointwise identical. Significant differences in the flow due to the duct were observed, with the initial computations showing that the concept of the flow-through duct works and the amount of mass ingested causes significant changes in the flow field around the model. The duct exit flow had a significant effect on the flow, particularly at Mach number M=0.75, and this flow interaction may set a maximum testing Mach number for the model. Intake flow ratios ($\frac{A_{\infty}}{A_c}$) up to 0.60 were observed, which are on the low end of relevance to real configurations, but still high enough to be valuable.