A Joint European Initiative to Develop Hybrid Grid Based CFD-Technology for Inviscid and Viscous Flow Computations Applicable to Geometrically Complex Aircraft Configurations

Abstract

A joint European initiative to develop hybrid grid based CFD-technology with a short problem-turnaround time applicable to complex aircraft configurations has been undertaken. In the context of the Brite-Euram fourth framework programme two projects have been executed, namely FASTFLO I (1996-1998) and FASTFLO II (1998-2000). The practical outcome of the joint development has been CFD technology with inviscid (FASTFLO I) and viscous (FASTFLO II) flow modelling for complex aircraft configurations (see figure 1 for an example). The resulting CFD technology is based on the hybrid grid approach (Ref. 7); this approach combines prismatic grid generation in a layer near aerodynamic surfaces with tetralhedral grid generation in the remainder of the flow domain. It has been concluded that the hybrid grid based CFD technology (both viscous, and inviscid flow models) meets the following two industrial requirements: 1. The CFD problem-turnaround time is within the order of a week for geometrically complex aircraft configurations and, 2. The CFD technology is able to provide a sufficient accuracy of the aerodynamic entities (like pressure, lift, drag and moments).