3.1 - Optimization of the illumination optics for gap flow velocity measurements in turbo machines
- Event
- AMA Conferences 2013
2013-05-14 - 2013-05-16
Nürnberg - Band
- Proceedings OPTO 2013
- Chapter
- O3 - Novel Measuring Technologies
- Author(s)
- R. Schlüßler, C. Blechschmidt, A. Fischer, J. Czarske - Technische Universität Dresden (Germany)
- Pages
- 52 - 57
- DOI
- 10.5162/opto2013/o3.1
- ISBN
- 978-3-9813484-3-9
- Price
- free
Abstract
Understanding and designing the tip leakage flow in turbo machines is one important point for i ncreasing their efficiency. Therefore optical flow velocity measurements in the less than 1 mm wide tip gap are necessary. These measurements are very challenging because disturbing light reflections e.g. from the rotor blade tip are increasing the measurement uncertainty. Hence, the disturbing light reflections need to be reduced.
Using diffraction theory it was possible to optimize the parameters of the illumination beam. Combined with an absorptive coating of the rotor tip, this results in a reduction of the disturbing light power by a factor of more than 100 compared to the previously used setup. This enables optical 3-dimensional-3- component flow velocity measurements in sub millimeter gaps.