Fast Aerodynamic Calculations Based on a Generalized Unsteady Coupling Algorithm

Abstract

An aerodynamic model for applications to external flows is formulated that provides a great trade-off between computational cost and prediction accuracy. The novelty of the work is the ability to deal with any unsteady flow problem, irrespective of the frequency of motion and motion kinematics. The aerodynamic model, baptised FALCon, combines an in-house unsteady vortex lattice method with an infinite-swept wing Navier-Stokes solver. The two specialised methods are orchestrated by an unsteady coupling algorithm that represents our main research contribution. The paper gives the formulation and algorithmic implementation. FALCon is demonstrated on three test cases of increasing complexity in flow physics, up to flow conditions well outside its validity range. On average, FALCon achieves a computational speed up of a factor of about 50, compared to a full Navier-Stokes run, while capturing relevant flow physics: three-dimensional, viscous, compressible and unsteady phenomena.

An unsteady aerodynamic model for three-dimensional wing based on augmented lifting-line method

“…Parenteau [19] coupled 2D Unsteady Reynolds-averaged Navier-Stokes (URANS) data with unsteady vortex lattice method and calculated the pitching wing at low reduced frequencies. Similar to Parenteau, Kharlamov [20] also used 2D URANS results as input, and studied the pitching wing at transonic speed. The above methods both can consider the viscosity, but none of them simplifies the 3D wake, thus the unsteady computation cost still remains high.…”