Transition Analysis for the Pazy Wing

The Pazy wing, designed as a benchmark for highly flexible wings that experience large
deformations, presents intriguing nonlinear phenomena due to its unique geometry with spanwise
varying static deformation and low Reynolds number flow conditions. These phenomena include limit
cycle oscillation related to laminar separation bubbles, boundary-layer transition, and dynamic stall.
The primary focus of this study is to investigate transition behavior on the sagged Pazy wing under
static loading by using the shear-stress-transport (SST)-based Langtry-Menter 𝜸 − 𝑹𝒆𝜽𝒕 transition
model in the NASA OVERFLOW and FUN3D solvers. Based on the steady-state results obtained via
different variants of the Langtry-Menter model, we investigate the likely transition behavior over a
range of incidence angles. The predicted flowfield on the sagged Pazy wing is strongly three
dimensional and the application of turbulence index as a viable indicator of the transition front in such
flows is also explored. The study demonstrates the limitations of the Langtry-Menter model when
applied to low Reynolds number flows. We introduce a spanwise periodic configuration to simulate a
narrow-span section of the Pazy wing, specifically centered on one of the 14 nearly equidistant ribs
spanning the wing. The computational results demonstrate that the spanwise periodic configuration
provides a straightforward environment for studying transition characteristics as well as
demonstrating systematic grid convergence and successful code-to-code comparisons. The research
offers useful insights into the transition characteristics of flexible wings under various loading
conditions, contributing to the field of aeroelastic simulations.