Flight Maneuverability Characteristics of the F-16 CFD and Correlation with its Intake Total Pressure Recovery and Distortion

Abstract

An investigation of the intake pressure recovery and distortion effects observed by varying maneuverability conditions of the F-16 was conducted. Simulations were conducted by using the Partial Differential Equation (PDE) calculator COMSOL. Results were validated with the classical s-duct, showing reasonable qualitative agreement. The maneuverability of the F-16 was defined using three factors: Mach number, angle of attack and angle of sideslip. The values of pressure recovery and distortion were measured at the Aerodynamic Interface Plane (AIP). Two sets of simulations were conducted: one to compare the sea level and 10 km altitude flight condition and another to correlate the required air intake and engine performance with pressure recovery and distortion at the AIP. Results of the flight level comparisons showed a slightly higher pressure recovery at 10 km of 0.985 compared to sea level condition value of 0.983. Distortion coefficient values for both conditions were however similar at 0.120. The difference in recovery values is attributed to the less viscous characteristic of air at higher altitude. This resulted in lower secondary flow formations in the intake. With increasing altitude, temperature plots showed a linear decreasing profile throughout the intake. The study provides a platform to a future model which couples the results obtained from the intake as inlet conditions to turbine flow simulations. This would provide a more holistic understanding of the propulsion system in the F-16.

Comparative Flow Field Analysis of Boundary Layer Diverter Intake and Diverterless Supersonic Intake Configuration

“…This is due to the fact that the shock waves at the inlet in supersonic condition causes additional pressure loss and hence it results in lower pressure recovery as compared (Goldsmith andSeddon 1993, Mattingly 2002). This phenomena is quite similar in fixed intakes (Ibrahim, Ng et al 2011). It is also evident that the pressure recovery of BLD (Config 1) is quite similar for both AoA at M # 0.6, however, at high subsonic and supersonic speeds pressure recovery at AOA 0 o is slightly higher than that at AOA 4º.…”

Numerical simulation of flow past a triangular prism with fluid–structure interaction

“…One of the main features of COMSOL Multiphysics is that meshes can be automatically generated according to the actual situation. When the triangular prism rotates in the flow field, if the maximum distortion of the mesh element is less than 4, which means that the mesh deformation is serious at this time, COMSOL will redivide the mesh and continue to operate (Ibrahim, Ng, & Wong, 2011).…”