Periodic Reporting for period 2 - HOMER (Holistic Optical Metrology for Aero-Elastic Research)
Okres sprawozdawczy: 2020-03-01 do 2022-02-28
In WP2 the assessment and validation of uncertainty quantification and performance measures of experimental measurement methods used in the WPs 3, 4 and 5 are under development. Data assimilation approaches allowing e.g. to determine pressure and loads distributions from particle tracks are developed and assessed by benchmark tests with synthetic and real experiments. A datasets on a fluid-structure interaction configuration has been generated numerically mimicking the experimental conditions of Task 3.1 and serve as benchmark test data including uncertainty quantification. This simulation data is used as ground truth for an international challenge on LPT and DA linked to a Workshop on WP 2 (http://cfdforpiv.dlr.de) and as well for the HOMER partners. Further work is dedicated to approaches aiming at improving the modelling of fluid flows, of structural dynamics, and also of models targeting their coupled dynamics. The final objective of these works is to provide more reliable models, complying with experimental data, to investigate complex fluid and fluid-structure phenomena.
In WP3 the assessment and validation of the HOMER experimental methodology, optical surface deformation measurement and velocimetry-based surface-pressure measurement techniques, have been achieved under experimental conditions. WP3 contains four tasks that address these aspects in different conditions. A turbulent boundary layer interacting with an actuated flexible surface panel has been investigated. Furthermore, small- and large-scale experiments in water- and wind tunnels, using simultaneous volumetric flow and model displacement measurements, on rigid and flexible wing models have been prepared and performed. Additionally, CFD simulations and structural analysis are used to support the design of the final experiments
In WP4 complete hydro- and aeroelasticity problems at low to moderate Reynolds numbers (1000 < Re < 2x10⁵) are under experimental investigation. Simultaneous measurements and subsequent computations of the three components of the Collar triangle are and will be performed, with the objective of fully resolving the unsteady dynamics of moving, flapping and/or deforming wings and surface panels. Of particular interest are the response, self-sustained motions and deformations of immersed bodies depending on their constitutive material and structure.
In WP5 the fluid structure interaction (FSI) of oscillating and deformable airfoil models at cruise flight and off-design Mach numbers are under investigation by using sophisticated optical imaging techniques (2D/3D PIV/PTV, PSP, Schlieren, Deformation). To accomplish this goal, five tasks were defined within this WP. Here, in total three 2D rigid wings of the same geometry (OAT15A), but with different degrees-of freedom for flutter analysis and with a flow control device, and one flexible wing (Jedelsky) are investigated in three independent transonic wind tunnel tests.
The HOMER project is aiming at establishing methods for experimental proof-of-principle and delivers data for their foundational scientific underpinnings supporting innovative coupling of CFD-CSM codes and related MDO design tool developments specifically with respect to FSI problems and phenomena. The corresponding research activities and development of analysis tools based on advanced optical metrology for fluid flows and surface motions and deformations making leading-edge science and technology research more collaborative between the branches of “structures” and “aerodynamics”. The project realizes experiments that support the validation needs of coupled CFD-CSM tool developments, enhance the physical knowledge about FSI phenomena and range from the assessment of the method (turbulent flow over a deforming surface) to relevant (non-linear) problems in aeronautics (transonic buffeting) and flapping flight mechanics. The developed experimental measurement systems will also become commercially available to interested research and industry inside and outside the aeronautical and transport industry which is secured through the involvement of the company participant LaVision.
The HOMER consortium partners are involved in various current and upcoming research and development projects in cooperation with relevant industrial partners from aviation, aerospace engineering, ground transportation and wind energy. This frame work is ideally suited to promote and disseminate the knowledge gained within the HOMER project.