3. (50 Points) A 787 Dreamliner is designed for Mach 0.77 flight at an altitude of 8.8 km with two turbofans each with inlet diameter of 2.65 m. The core compression ratio is 11 with variable efficiency ne. The turbine inlet temperature after the combustor is 1350° C and has a variable turbine efficiency nt. The fan has a compression ratio 2.8 and bypass ratio a = 4.5. Assume the quantity of fuel added is 1.6%, constant specific heat, determine the following as a function of variable ranges 0.66 and 0.77 0.96: (a) Total temperature at after each turbomachinery component (b) Exit velocities of both the core and the fan 0.92 (c) Thrust force generated by the engine assuming full expansion of the nozzles P = Po (d) Specific thrust (e) Thrust specific fuel consumption Use the combination of idealized and efficiency ratios to determine which of the adjust- ment variables has the greatest impact on each of the parameters calculated? Extra Credit: (20 Points) Explore performance characteristics as a function of altitude. How does the change of properties for the inlet flow affect the performance away from operational design?

Fig: 1