AIAA-2015-3867 Effect of Water and Humidity on Hypergolic Propellant Ignition Delay
Figure 6. Raw streak data from the same case #1 test The streak data intensity is summed over a prescribed wavelength range and normalized by the width of that range in nanometers. The OH signals cover 306 nm to 308 nm and 308 nm to 312 nm. The NH signal is summed over 335 nm to 337 nm. To improve the time response of the photodiode and streak camera data, Butterworth filters are applied to reduce the noise. The photodiode is low-pass filtered at 300 Hz and band-stop filtered from 55 Hz to 65 Hz. The streak data is only low-pass filtered at 1000 Hz. All values presented from the photodiode and streak camera are from the filtered data. The data from the same test shown in the previous two figures are plotted in Figure 7. For this test, the IDT determined by the photodiode isms, the onset of NH is at 10.0 ms and the onset of OH is at 12.74 ms. The data from this test campaign show that the video provides the earliest signal of ignition followed by the photodiode and then the streak data, although there are cases which do not follow this trend. Downloaded by PURDUE UNIVERSITY on July 21, 2017 | http://arc.aiaa.org | DOI: 10.2514/6.2015-3867
