This question is regarding the P&W 4000 engine that was involved in the recent incident on UAL 328, but it doesn’t have to be specific to that engine.
From what I gather in this incident the fire continued after both fire suppression bottles had been deployed. I’m wondering where exactly does the suppression material go into the engine? Does it all flow into the core or is it distributed to different places. Does the loss of the cowl render it ineffective? I expect that halon would only work in an enclosed space. It appears that the fire in this incident was outside the core and without the cowl there wouldn’t be much that could be done in flight to put it out.