Determining the contribution of the structure inertia forces requires the accurate measurement of its distributed motion and deformation. This is often pursued with a combination of installed sensors (accelerometers) and optical techniques that track the structure as a whole or in parts. Connecting the resulting data with flow measurements is a challenging task as two separate systems need to be jointly operated and mutually calibrated. The unified approach followed in HOMER for cases where the model can be fully immersed into the flow measurement volume is in principle simpler as the structure motion analysis can be performed with the same imaging system used for the flow diagnostics so that the procedures for the analysis of fluid and structure motion will deliver integrated and coherent information. The development of this simplified and faster approach within HOMER (only one system of cameras need to be calibrated) will be based on the advanced LPT technique Shake-The-Box (STB), which will track the fluid tracer particles and distributed surface point markers (advanced point tracking) during the same evaluation step. An uncertainty assessment comparing the different existing and novel surface deformation measurement techniques based on synthetic and experimental test cases will be performed within the scope HOMER.
A thread throughout the project is the description of the motion of wall panel flutter induced by a turbulent boundary layer flow over them. The response of flexible panels to the flow over them is a challenging topic, which requires simultaneous flow and surface measurements. These measurements are typically restricted to small volumes and areas. The goal within the current project is to create and validate experimental tools that will allow to capture both the surface deformation and the flow in a large volume simultaneously. Combining techniques that can use LPT to improve the description of the flow, and obtain pressure fields with surface measurements and including both in data assimilation approaches will allow us to describe panel flutter better and in more detail.