In this study, T56 turboprop engine was theoretically modelled for 75% load, 100% load, military (MIL)
mode, and Take-off mode conditions. For each load conditions, thermoeconomic analyses of T56 turboprop engine
were performed to allocate the unit costs of shaft work and thrust and to determine exergy destruction cost rates for
system equipment. In thermoeconomic analyses, Specific Exergy Costing (SPECO) and Modified Productive Structure
Analysis (MOPSA) methods were used. MOPSA method gave higher unit cost values for shaft work and thrust
compared to SPECO method. As a result, for Take-off mode, the unit cost of shaft work transferred to propeller was
determined to be 78.87 $/GJ in SPECO method, while this value was calculated to be 84.68 $/GJ with MOPSA method.
The unit cost of negentropy of T56 turboprop engine decreased with increasing in engine load and ranged from 14.98
$/GJ to 11.08 $/GJ. The exergy destruction cost rates obtained with MOPSA method for the system equipment were
considerably lower than the results obtained with SPECO method. For instance, in Take-off mode, exergy destruction
cost rate of combustion chamber was calculated to be 865.10 $/h in SPECO method, whereas it was calculated to be
247.94 $/h in MOPSA method. The exergoeconomic factor of overall system was determined to be 23.07% in SPECO
method, and 54.16% in MOPSA method for Take-off mode.