Wing-body aeroelasticity on parallel computers

This article presents a procedure for computing the aeroelasticity of wing-body configurations on multiple-instruction, multiple-data parallel computers. In this procedure, fluids are modeled using Euler equations discretized by a finite difference method, and structures are modeled using finite element equa- tions. The procedure is designed in such a way that each discipline can be developed and maintained independently by using a domain decomposition approach. A parallel integration scheme is used to com- pute aeroelastic responses by solving the coupled fluid and structural equations concurrently while keep- ing modularity of each discipline. The present procedure is validated by computing the aeroelastic re- sponse of a wing and comparing with experiment. Aeroelastic computations are illustrated for a high speed civil transport type wing-body configuration. HE analysis of aeroelasticit y involves solving fluid and structural equations together. Both uncoupled and coupled methods can be used to solve problems in aeroelasticit y associated with nonlinear systems.1 Uncoupled methods are less expensive but are limited to very small perturbations with moderate nonlinearity. However, aeroelastic problems of aero- space vehicles are often dominated by large structural defor- mations and high flow nonlinearities. Fully coupled pro- cedures are required to solve such aeroelasticity problems accurately. Such coupling procedures result in an increased level of complication. Therefore, aeroelastic analysis has been mostly performed by coupling advanced computational fluid dynamics (CFD) methods with simple structural modal equations or ad- vanced computational structural dynamics (CSD) methods with simple flow solutions. However, these approaches can be less accurate for the aeroelastic analysis of practical problems such as a full aircraft configuration in transonic regime. It is necessary to develop a fully coupled procedure utilizing ad- vanced computational methods for both disciplines. Recently, coupled fluid-structural interaction problems are being studied using finite difference Euler or Navier-Stokes flow equations and finite element structural equations of mo- tion as demonstrated by an aeroelastic code ENSAERO.2'3 However, applications are limited to simple structural models. For the complicated fluid and structural models, computations are performed in a step-by-step fashion.4 The main reason is that the use of detailed models for both disciplines requires unprecedented computing speeds and amounts of memory. The emergence of a new generation of parallel computers can pos- sibly alleviate the restriction on the computational power. To solve the coupled fluid-structural equations some at- tempts have been made to solve both fluids and structures in