Pulse-jet propulsion and Ram-jet propulsion

Ram-jet propulsion and pulse-jet propulsion are semantically related in propulsion by jet discharge topic. In some cases you can use "Ram-jet propulsion" instead a noun phrase "Pulse-jet propulsion".

Pulse-jet propulsion and ram-jet propulsion are semantically related in propulsion by jet discharge topic. You can use "Pulse-jet propulsion" instead a noun phrase "Ram-jet propulsion".