“…where 21 W is the fan core duct outlet flow capacity, 22 W the booster inlet one, 23 W the booster outlet one, 24 W the high pressure compressor (HPC) inlet one, 4 W the combustor outlet one, 41 W the high pressure turbine (HPT) outlet one, 42 W the low pressure turbine (LPT) inlet one, 5 W the LPT outlet one, 9 W the nozzle core duct outlet one, 16 W the fan bypass duct outlet one, 19 W the bypass duct outlet one. Four cooling air streams The CLM in steady state has eight balance equations, seen in Equations (17) and (18), therefore, there are eight guess variables used to determine the engine steady operating condition, which are low pressure spool speed L n , high pressure spool speed H n , fan blade tip pressure ratio Ft , fan blade root pressure ratio Fr , booster pressure ratio B , compressor pressure ratio C , HPT pressure ratio HT , and LPT pressure ratio LT .…”