Reduced-order modeling of complex aerodynamic geometries using canonical shapes

The aerodynamics of bluff bodies are of interest in several engineering applications. The numerical prediction of the behavior of these geometries requires high fidelity approaches, the cost of which increases with the complexity of the body of interest. Thus, design and modeling and simulation solvers are usually limited to surrogate data on canonical shapes and/or estimates based on flat plate drag area. A new concept, the COMPlex Aerodynamic Shape Simulator (COMPASS), is proposed to estimate the quasi-steady aerodynamic coefficients for arbitrary configurations, which can then be applied in unsteady reduced-order models and design software. This approach decomposes complex shapes into an aggregate of canonical bodies, and then computes the aerodynamic characteristics of the complex geometry from the separation and reattachment properties of the relevant canonical shapes. This paper introduces the initial method which applies a rectangular bluff body as the canonical shape. The baseline COMPASS has been analyzed on one canonical shape (rectangular prism), and two complex configurations (truck and trailer). The resulting aerodynamic properties have been compared with Computational Fluid Dynamics (CFD) and experimental data. COMPASS is shown to be a viable concept for the estimation of the quasi-steady aerodynamic loads of the complex shapes analyzed. Additional on-going development of COMPASS is also summarized.