The intake represents the front of a complex aerodynamic system. The shape of the intake diffuser follows the contours of the aircraft for external aerodynamic reasons. However the meandering shape can result in unwanted secondary flow or swirl build up at the Aerodynamic Interface Plane (AIP), resulting in engine flutter and stall. Using the Finite Element Method (FEM) Partial Differential Equations (PDE) calculator COMSOL, the compressible flow equations were obtained by the coupling of the continuity and momentum equations in the k-ε turbulence model and the energy equation conduction and convections model. The standard validation and verification techniques employed in the computational analysis were conducted in the study of F-5E and F-16 aerodynamic intakes. The results were validated using experimental results of the circular S-duct. Static pressure contours of the S-duct were compared at the azimuthal angles 0 ο , 90 ο and 180 ο with reasonable agreement. The Grid Convergence Index (GCI) study done on the circular S-duct, F-5E and F-16 intakes using the pressure recovery as variable. Results showed that fine grid solution error had a maximum error of 2.18%, 4.48% and 3.17% respectively. Comparisons were then made on the flow through the F-5E and F-16 intake only showing that the doubly offset F-5E intake had a more adverse effect on secondary flow formation. The addition of the pre-entry domain resembling that of the underbelly of the fuselage in addition to the intake itself was then implemented on the F-16 intake. Different maneuverability conditions (Mach number, AOA and AOS) were conducted on this F-16 geometry. The results were investigated via total pressure and swirl flow diagrams. Air quality was defined as the pressure recovery and the distortion coefficient that exists at the AIP. Addition of the pre-entry separation area resulted in more pressure recovery losses compared to studying the intake alone. However with increasing AOA, the underbelly of the fuselage acts as a flow straightener. Pressure losses were essentially small up to 20 ο AOA. The pressure recovery II and distortion characteristics of the intake with relation to changing AOS shows symmetry in the z-axis, the axis parallel to the transverse of the intake, as the intake was fundamentally a singly offset entity. The results were also correlated on a typical F-16 flight placard. Finally, the Taguchi's Method (TM) and Analysis of Variance (ANOVA) were conducted on the F-5E intake and the F-16 intake with pre-entry domain. They were used to analysis the effects of the factors and their interactions on the performance parameters of the intake. The results showed that for the F-5E intake, Mach number had the most effect on pressure recovery while AOA affected distortion most considerably. The F-16 intake, shielded at the underbelly of the fuselage, showed that the factor that resulted in pressure recovery change most considerably is the AOS, while AOA affected distortion most considerably. The two results were further reinforced with res...
