This time with better info.
So we experimented with pintile placement using a simple system just to get some initial data. In order to avoid things like combustion instability and to allow for film cooling, achieving a good fuel mixture is critical for the success of our project.
Our first one has a clear gap in the flow distribution:
After a few tweaks to the gap size from the pintile we got a much more even flow:
For reference, here is what the injector looks like (in assembly):
And here’s two videos. One at a low pressure and poor pintile placement. The other at closer to optimal conditions.
Failure First:
Success Second:
Oregon Tech Rocketry and Aerospace 