This work reports the experimental demonstration of 5 kHz visualization of turbulent flows in all three spatial dimensions (3D) based on volumetric laser induced fluorescence (VLIF). The measurements were performed based on the LIF signal of iodine (I2) vapor seeded in the flow. In contrast to established planar LIF (PLIF) technique, the VLIF technique excited the seeded I2 vapor volumetrically by a thick laser slab. The volumetric LIF signals emitted were then simultaneously collected by multiple cameras from different orientations, based on which a 3D tomographic reconstruction was performed to obtain the 3D distribution of the I2 vapor in the target flow. Single-shot measurements obtained in a duration of ~300 ns (limited by the pulse duration of the excitation laser) were demonstrated in a measurement volume of ~50 × 50 × 50 mm at a repetition rate of 5 kHz. These measurements demonstrated the feasibility and potential of VLIF for resolving the 4D spatiotemporal dynamics of turbulent flows.
|Original language||English (US)|
|Title of host publication||32nd AIAA Aerodynamic Measurement Technology and Ground Testing Conference|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|Number of pages||6|
|State||Published - 2016|
|Event||32nd AIAA Aerodynamic Measurement Technology and Ground Testing Conference, 2016 - Washington, United States|
Duration: Jun 13 2016 → Jun 17 2016
|Name||32nd AIAA Aerodynamic Measurement Technology and Ground Testing Conference|
|Other||32nd AIAA Aerodynamic Measurement Technology and Ground Testing Conference, 2016|
|Period||6/13/16 → 6/17/16|
Bibliographical noteFunding Information:
This work is supported by the U.S. Air Force Office of Scientific Research (AFOSR) with Dr. Chiping Li as the technical monitor (grant FA9550-14-1-0386). Development of the imaging processing algorithms and the LIF imaging of I2 vapor used here was supported by an NSF award (Award CBET 1156564).
© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.