The Application of Laser Rayleigh Scattering for Observation in Supersonic Airflow with Ethylene Injection

Abstract

Laser Rayleigh scattering is applied toward measurements of gas visualization thermometry and combustion reaction With the advantages that Rayleigh scattering is elastic and coherent the signal is easier to detect than Raman scattering and could be enhanced by other factors example: light source This study discusses the application of laser Rayleigh scattering for measurements in supersonic airflow with hydrocarbon fuel injection The experimental study is conducted in two different facilities The correction experiment is conducted in an observation tank and the flow visualization experiment is conducted in in a reflected shock tunnel at National Cheng Kung University Ethylene become the candidate of the test fuel refer to other studies with similar choice The correction of the relationship between gas pressure and signal intensity ensure the signal intensity is proportional to gas pressure The correction of the relationship between ethylene concentration in air and signal intensity build a correction function for the flow visualization experiment The measurement about ethylene concentration in mixing gas of ethylene injection in supersonic airflow exist amounts of deviation Although this method is lack of accuracy about measurement of mixing gas pressure or ethylene concentration it could measure the structure and forming of ethylene injection in detail To improve the accuracy of the measurement block the background noise by moving the pathway of laser light or install more baffle system; Enhance the signal intensity by searching the decent exposure time in ICCD camera

Date of Award	2019
Original language	English
Supervisor	Hsiao-Feng Yuan (Supervisor)