{ "cells": [ { "cell_type": "markdown", "id": "controversial-professional", "metadata": {}, "source": [ "\n", "\n", "This work is licensed under a [Creative Commons Attribution 4.0 International License](http://creativecommons.org/licenses/by/4.0/).\n", "\n", "# Analyzing PIV data of a longitudinal vortex\n", "\n", "In this notebook, we analyze particle image velocimetry (PIV) data of a dynamically meandering longitudinal vortex. The data were recorded and provided by [Nils Rathje](https://www.tu-braunschweig.de/en/ism/research/aerodynamics-of-aircraft/staff/rathje) of TU Braunschweig's institut of fluid mechanics as part of a DFG-funded project. A delta-wing configuration with a swept angle of $65^\\circ$ was investigated in the institut's low-speed wind tunnel ([MUB](https://www.tu-braunschweig.de/ism/institutsausstattung/windkanalanlagen/mub)) by means of a time-resolved stero-PIV. The data were recorded with a frequency of $3kHz$ with $7ms$ between double frames using the software package DaVis 8.4 by [Lavision](https://www.lavision.de/en/products/flowmaster/2d-stereo-piv/index.php). A final window size decreased to $32\\times 32 px^2$ was used with $50\\%$ overlap, which corresponds to a resolution of $\\Delta x = \\Delta y = 1,5mm \\left( \\widehat{=} 16px \\right)$.\n", "\n", "The flow conditions may be summarized as follows:\n", "\n", "- free stream velocity $U_{\\infty}=55.5 m/s$\n", "- Reynolds number $Re\\approx 0.99\\times 10^6$\n", "- ambient temperature $T\\approx 37^\\circ C$\n", "- angle of attack $\\alpha = 8^\\circ$\n", "\n", "