A Local Analysis of the Fluid Dynamics and Flow Physics of Dynamic Stall on Helicopters
Abstract
High-fidelity blade section simulations are carried out that capture essential features of the flow over entire helicopter rotor blades in forward flight. The unsteady flow data obtained from the simulations are analyzed to identify underlying hydrodynamic instabilities. The research contributes to the understanding of the flow physics of dynamic stall on helicopters. A combined approach comprised of computational fluid dynamics simulations along with advanced data analysis techniques and theory is employed for the research. The hypothesis is that the examination of instabilities, both in isolation and in concert, will yield useful information about nonlinear interactions. To isolate the instabilities, the complex flow field is decomposed into ÒcanonicalÓ flows. Four different "canonical" flows are modeled through blade section simulations that are undergoing a cyclic surging, pitching, or sweeping motion or that are exposed to rotational effects. The flow data resulting from the simulations are analyzed with the proper orthogonal decomposition and the dynamic mode decomposition. The analyses are intended to reveal the nature of nonlinear interactions, to identify instabilities that can be exploited for an effective dynamic stall control, and to inform new control strategies/actuation schemes that specifically target the nonlinear coupling of multiple instabilities.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510235
Entities
People
- Andreas Gross
Organizations
- Army Contracting Command
- New Mexico State University
- United States Army