Sensitivity analysis of nacelle intake high-incidence aerodynamics including a body force fan model

Nacelle intakes are designed to operate in a variety of flow conditions where different requirements make the solution a best compromise in terms of conflicting requirement that are established. In this paper we propose a numerical study of a civil aeroengine nacelle sensitivity to high-incidence conditions. The research is carried out by means of a design space exploration on intake geometries, in order to evaluate the geometric parameters that affect the distortion level, the total pressure losses, and the separation angle of attack. A parameterisation tool using B-Splines is employed to generate a series of intakes fitted on a baseline axisymmetric nacelle. Simulations are performed either by imposing standard boundary conditions at the fan face plane or by using a body force method to represent the fan. The validated body force model of a transonic fan is used to simulate the intake/fan coupling and its effects on the high-incidence aerodynamics. The study establishes a numerical procedure for the analysis of the design space, showing that the despite a different distortion level predicted at the aerodynamic interface plane using the two modelling approaches, they provide qualitatively consistent trends for optimal geometric parameters in this case study.