ROTATIONAL AND VIBRATIONAL RAMAN SPECTROSCOPY FOR FLOW FROM AN UNDEREXPANDED JET NOZZLE
Abstract
The objective of this work is the construction of a fully functioning Raman line imaging spectrometer; and the measurement of pressure, temperature, and chemical concentration in supersonic flows issuing from a jet nozzle. The measurements will be carried out using roational-vibrational Raman line imaging through the axis of the jet exhaust. In this way measurements of the flow field under high pressure, temperature, and velocity can be made without disrupting it. Because of the increasing push for better fuel efficiencies in modern propulsion devices, it is essential to examine the flow fields within these devices more closely. The high pressure and temperature, even supersonic, environments that are within these modern day devices are simulated by examining the properties of Mach disks in the exhaust of an underexpanded nozzle. Benefits of this research can be applied to turbojets, ramjets, afterburners, and rockets to increase efficiency and overall thrust. Laser techniques have often been used in the past to measured temperature at a known constant pressure or were able to collect both but for only one type of molecule. The technique being used offers pressure, temperature, and chemical makeup measurements for a non uniform flow field for all the different molecules. Very few labs in the world can perform these types of measurements, and such a lab is currently being assembled on campus. The result of the research at hand is a lab facility with a Raman spectrometer and laser optical system capable of collection spectral data, and an initial investigation into the properties of Mach disks.
Citation
Bayeh, Alexander (2008). ROTATIONAL AND VIBRATIONAL RAMAN SPECTROSCOPY FOR FLOW FROM AN UNDEREXPANDED JET NOZZLE. Available electronically from https : / /hdl .handle .net /1969 .1 /85731.