Project Details
Projekt
High-speed and high-resolution 4 D optical flow-diagnostics system
Subject Area
Fluid Mechanics, Technical Thermodynamics and Thermal Energy Engineering
Term
from 2022 to 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 513183059
The institute of fluid mechanics (ISTM) at Karlsruhe Institute of Technology (KIT) has developed a reputation as international reference for the studies on near wall turbulence and its control or modification through specific geometric patterns, wall roughness or by means of both active and passive flow control approaches. The present proposal aims at enabling high fidelity optical measurements in the two recently upgraded facilities at ISTM: a low Reynolds number (Re) channel-flow tunnel and a large high-Re open jet wind tunnel. Complementary experimental and numerical investigations are envisioned for both flow configurations. This enables the following holistic research approach on wall-turbulence mechanisms and control: For the canonical channel flow, high-fidelity direct numerical simulations (DNS) drive the fundamental understanding of the underlying physics. These classical simulations of a statistically 2 D and spatially fully developed flow state are complemented by spatio-temporally resolved experiments. These experiments allow to assess flow development and three-dimensionality effects absent in DNS and, most importantly, provide access to flow phenomena triggered by actuators or surface roughness, which even in DNS are included based on model assumptions and thus require validation data. The state-of-the-art equipment requested for these studies is referred to as (temporally and volumetrically resolved) high-speed 4 D optical flow-diagnostics system. In addition to their fundamental investigation in the channel flow configuration, the flow control and modification strategies are transferred to more complex configurations; specifically, to external flows along complex geometries at higher Re. For this flow type high-fidelity simulations are extremely demanding or impossible. Therefore, turbulence-model based solvers are deployed. In order to advance models that allow the incorporation of modified boundary conditions due to non-smooth surfaces or the presence of actuators, reliable experimental data for input and validation are mandatory. This requires high resolution volumetric measurements of large flow domains. For this sake, a second flow diagnostics system is requested, which is referred to as high-resolution 4 D optical flow-diagnostics system. This system can be used in combination with an already available laser source at ISTM, to deliver four temporally-correlated sequences of volumetric measurements. The acquired datasets will be processed with the most advanced algorithms based on the Lagrangian particle tracking (LPT) approach, including state-of-the-art volumetric Lagrangian velocimetry software retrieving high-quality measurements with computationally-efficient data evaluation. The requested equipment thus allows to fully exploit the newly refurbished wind tunnel infrastructure at ISTM in order to enable a unique holistic flow diagnostics and control research.
DFG Programme
Major Research Instrumentation
Major Instrumentation
zeitlich und räumlich hochauflösendes optisches 4D-Strömungsdiagnosesystem
Instrumentation Group
8860 Geschwindigkeitsmeßgeräte (außer 047, 053, 192 und 244)
Applicant Institution
Karlsruher Institut für Technologie
