Computation of Viscous Flow for a Boeing 777 Aircraft in Landing Configuration

Abstract

A series of Navier-Stokes simulations of a complete Boeing 777-200 aircraft con gured for landing is obtained using a structured overset grid process and the OVERFLOW CFD code. At approach conditions, the computed forces for the 777 computation are within 1.5 of experimental data for lift, and within 4 for drag. The computed lift is lower than the experiment at maximum-lift conditions, but shows closer agreement at post-stall conditions. The e ect of sealing a spanwise gap between leading edge elements, and adding a chine onto the nacelle is computed at a high angle of attack. These additions make a signi cant difference in the ow o ver the wing near these elements. Detailed comparisons between computed and experimental surface pressures are shown. Good agreement is demonstrated at lower angles of attack, including a prediction of separated ow on the outboard ap. Introduction Calculating the viscous uid ow over a high-lift Aerospace Engineer. y Chief, Aerospace Operations Modeling O ce. Senior Member AIAA. z Principal Engineer. x Principal Engineer. Senior Member AIAA. Engineer Scientist Specialist. Member AIAA. k Research Engineer.

CFD technology development at NASA Ames - A mission computing perspective

“…In order to develop aerodynamic analysis capability of an aircraft during landing with flaps/slats deployed, multielement airfoil computations were performed first (see summary by Rogers, 1994). Viscous flow computation procedures for a full landing configuration of a transport aircraft were developed by the NASA Advance Subsonic Technology (AST) program (Rogers et al, 2001). Kwak and Kiris, Mechanical Engineering Reviews, Vol.3, No.1 (2016) [DOI: 10.1299/mer.15-00429] Overset methods enabled detailed studies of the viscous flowfield with high-lift devices deployed, and procedures for obtaining accurate solutions of the Navier-Stokes equations in wake flow with near the onset of blunday layer separation.…”

“…At approach conditions, computed lift was within 1.5% of experimental data and within 4% for drag. Full detail can be found in Rogers et al (2001).…”

Viscous Flow Analysis of a Twin-engine Commercial Transport Aircraft in High Lift Landing Configuration

“…The inboard wing flow-field is characterized by strong and unsteady interactions of the nacelle-chine vortex with the wing boundary layer. Previous attempts at resolving this issue have been reported by Rogers, et al 8 , and Slotnick, et al 9 . A steady-state computational model may not be adequate for accurately capturing this interaction.…”

Progress toward CFD for full flight envelope

“…in modelling these high-lift configurations. Figures 21 and 22 show the overset grids and OVERFLOW solution of an aircraft with a complex highlift system (20,21) . OVERFLOW excels for use on configurations with significant geometric complexity or features not captured by the automation in the block structured codes.…”