OCR Text |
Show large droplets between pulses, but this particular configuration was unsuccessful. After several runs it was determined that more detailed knowledge of the pulse atomization process was required to correctly choose pulse combustor operating conditions and injector configurations which improve the atomization quality and throughput. The photographic studies were a way of addressing these problems. 3.2 Photographic Studies Photographic studies were carried out for both injectors for a single tailpipe and pulse combustor operating condition. The injectors were mounted vertically immediately at the tailpipe exit, with the liquid flowing down across the exit. Water was used in these ' initial tests, since it shows the overall atomization phenomena, but slurry will be used in later tests. Figure 8 shows a series of photos of the atomization from the large injector with increasing delay times. The flash was triggered by the pressure transducer nearest to the end of the tailpipe, so that the picture at zero delay is essentially at the moment the pressure pulse reaches the liquid stream. It should be kept in mind that each picture in the series is of the atomization event resulting from a different pressure pulse, so that we are not seeing the development through a single pressure cycle, but rather a series of cycles. The flow is from right to left, with the end of the tailpiece shown at the far right of each photo. The conditions for this run were a water flow of 2 gis, propane at .23 g/s and air at 3.6 g/s. It can be seen that initially there is a burst of atomized water to the left of the injector, after which a trail |