Optical high-speed Schlieren imaging arrangement for visualizing non-linear ultrasound phenomena within an ultrasound drug delivery system
Khan, Matiullah (2022)
2022
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202301301775
https://urn.fi/URN:NBN:fi:amk-202301301775
Tiivistelmä
The aim of this project was to establish a schlieren imaging system (SIS) which was coupled with a high-speed camera (HSC). For assembling SIS, a number of optical components were arranged. Later on, additional optical components were added to achieve high quality SIS with image sensitivity.
The goals were to visualize the gas flow in air using SIS, and then to visualize the density disturbances in water due to propagation of ultrasound (kPa to MPa range), and the shock waves (MPa range) in an ultrasound drug delivery system. In addition, other non-linear phenomena were observed. For example, a cavitation bubble collapse was visible in the images. The frame rate of HSC was used up to 800,000 fps. Furthermore, the visual information in the schlieren images was calibrated to show spatial pressure distributions in SI units (pascals) in water.
Based on the literature review, several SIS models, and systems were studied. Initially, a simple SIS was designed. For assembling the SIS, optical components were arranged. The assembled SIS was used for visualizing the images. The SIS was modified time to time by adding a cage lens system, a focusing lens, and a 3D rotational assembly.
In the modified SIS, more optical components were added that resulted in better sensitivity, image contrast, and field uniformity in the images. Using SIS, the visibility of the cavitation bubble collapse in the images, visualization of the shock waves, ultrasonic pressure measurement were successfully performed.
In conclusion, the proposed SIS was assembled, and then modified with the addition of more optical components. The modified SIS worked-well in achieving the best visualization of the images in terms of image contrast, image sensitivity, and field uniformity in the images.
The goals were to visualize the gas flow in air using SIS, and then to visualize the density disturbances in water due to propagation of ultrasound (kPa to MPa range), and the shock waves (MPa range) in an ultrasound drug delivery system. In addition, other non-linear phenomena were observed. For example, a cavitation bubble collapse was visible in the images. The frame rate of HSC was used up to 800,000 fps. Furthermore, the visual information in the schlieren images was calibrated to show spatial pressure distributions in SI units (pascals) in water.
Based on the literature review, several SIS models, and systems were studied. Initially, a simple SIS was designed. For assembling the SIS, optical components were arranged. The assembled SIS was used for visualizing the images. The SIS was modified time to time by adding a cage lens system, a focusing lens, and a 3D rotational assembly.
In the modified SIS, more optical components were added that resulted in better sensitivity, image contrast, and field uniformity in the images. Using SIS, the visibility of the cavitation bubble collapse in the images, visualization of the shock waves, ultrasonic pressure measurement were successfully performed.
In conclusion, the proposed SIS was assembled, and then modified with the addition of more optical components. The modified SIS worked-well in achieving the best visualization of the images in terms of image contrast, image sensitivity, and field uniformity in the images.