A six-phase thermodynamic cycle for a rotary internal combustion engine with a double rotation centre, the engine comprising a housing with intersecting circular expansion and compression chambers (120, 110), a dynamic central intake chamber and a static Z combustion chamber at the top thereof; a power rotor; a following rotor; a rotating shaft; and a drive means, the six-phase thermodynamic cycle comprising: Phase 1 wherein in an intake phase, a volume of air enters the central intake chamber of the housing through a peripheral air intake port and mixes with recirculated exhaust gas from phase 3; Phase 2 wherein in a first compression phase, the volume of air and recirculated exhaust gas from phase 1 is compressed at a low compression ratio by the reducing volume of the dynamic intake chamber within the housing; Phase 3 wherein in a combined scavenge and exhaust gas recirculation phase, a portion of the volume of air and recirculated exhaust gas from phase 2 scavenges the static combustion chamber and partially scavenges the expansion chamber, the dynamic expansion chamber then merges with the dynamic central intake chamber recirculating the residual exhaust gas from phase 6 within the housing; Phase 4 wherein in a second compression phase, the dynamic intake chamber separates to form a dynamic compression chamber and the residual volume of combined exhaust gas and air from phase 2 is compressed at a high compression ratio into the static combustion chamber within the housing; Phase 5 wherein in a power phase, a dynamic expansion chamber is formed, originating from the static combustion chamber and torque is produced to turn the output shaft; and Phase 6 wherein in an exhaust phase, exhaust gas from phase 5 is discharged from the dynamic expansion chamber through a peripheral exhaust port in the housing. Phase 1 wherein in an intake phase, a volume of air enters the central intake chamber of the housing through a peripheral air intake port and mixes with recirculated exhaust gas from phase 3; Phase 2 wherein in a first compression phase, the volume of air and recirculated exhaust gas from phase 1 is compressed at a low compression ratio by the reducing volume of the dynamic intake chamber within the housing; Phase 3 wherein in a combined scavenge and exhaust gas recirculation phase, a portion of the volume of air and recirculated exhaust gas from phase 2 scavenges the static combustion chamber and partially scavenges the expansion chamber, the dynamic expansion chamber then merges with the dynamic central intake chamber recirculating the residual exhaust gas from phase 6 within the housing; Phase 4 wherein in a second compression phase, the dynamic intake chamber separates to form a dynamic compression chamber and the residual volume of combined exhaust gas and air from phase 2 is compressed at a high compression ratio into the static combustion chamber within the housing; Phase 5 wherein in a power phase, a dynamic expansion chamber is formed, originating from the static combustion chamber and torque is produced to turn the output shaft; and Phase 6 wherein in an exhaust phase, exhaust gas from phase 5 is discharged from the dynamic expansion chamber through a peripheral exhaust port in the housing.