https://social.thangs.com/m/372572 Here's the new injector parts with 135 degree impingement. Impingement is less important than conventional rocket engine in this case because your fuel and oxidizer is both gas state (or are you using cryogenic?) but current setup of 3mm offset from fuel to oxygen injection nozzle is a bit too inefficient at mixing them. I don't think spiraling any of it will help at all despite all the comments below because speed of them rotating would be negligible compare to speed of the wave front once the ignition start.

where are the japanese papers?

https://social.thangs.com/m/370137

remixed it changed your gas inlet holes to spirals to get the mass of the air and fuel spinning (reduced to 20 holes to leave wall thickness)

also added a grooved start to the barrel

get the gasses spinning pre ignition then hopefully the detonation will follow the spinning mass starting the RDE

Iknow is a 3D model but have you try adding barrel rifling or similar to that . it could help the detonation just how it would with a bullet !

Interested in the Paper that you had mentioned.