Assessing Exergy-Based Economic and Sustainability Analyses of a Military Gas Turbine Engine Fueled with Various Fuels

This research put forth exergy-based economic and sustainability analyses of a (J85-GE-5H) military turbojet engine (TJE). Firstly, sustainability, conventional exergoeconomic and advanced exergoeconomic cost analyses were executed utilizing kerosene fuel according to real engine working circumstances. The engine was likewise investigated parametrically, considering H2 fuel utilization. The sustainable economic analysis assessment of the TJE was finally actualized by comparing the acquired outcomes for both fuels. The entire engine’s unit exergy cost of product (cPr) with kerosene was determined 76.45 $/GJ for the military (MIL) process mode (PM), whereas it was computed 94.97 $/GJ for the afterburner (AB) PM. Given the use of H2, the cPr increased to 179 and 288 $/GJ for the aforementioned two modes, seriatim. While the sustainability cost index (SCI) values were obtained 52.86 and 78.84 $/GJ for the MIL and AB PM, seriatim, they became 128 and 244 $/GJ when considering H2. Consequently, the higher exergy demolitions occurring in the afterburner exhaust duct (ABED) and combustion chamber (CC) sections led to higher exergy destruction costs in the TJE. However, the engine worked less cost efficient with H2 fuel rather than JP-8 fuel because of the higher cost value of fuel.


Introduction
Energy is an underlying phenomenon in thermodynamics and the production phase of energy is based on the notable applications of engineering examination. The systems which generate power are designed simple in order to convert energy into another. Regardless of energy, type and mode of production, it takes place in every aspect of life as a parameter that constitutes the most important agenda of our near future. The increase in energy demand is directly proportional to technological development, population and economic growth. In this context, the increase in global warming and air pollution has become the focus of energy analysis because of post-combustion products released into the atmosphere [1][2][3][4]. Aviation, standing out as the sector that creates the most energy consumption and the most pollution, is the main field of international research [5][6][7][8][9][10][11]. In order to provide the basis for sustainable environment-friendly policies, the road map provided in the 2018 report predicts that fossil energy resources will provide a significant share in energy production by the 2040s [12]. Energy engineers must deal with the reduction of oil reserves in the world by taking into account the increase in oil prices and environmental concerns by that time. This then draws the attention of researchers as an important issue, waiting to be resolved. Therefore, the importance of using alternative

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Reckon the exergy destruction costs of the entire engine and sections; • Investigate the exergy, exergoeconomic and sustainability performance parameters for the military (MIL) and afterburner (AB) process modes (PM) for both kerosene and hydrogen fuel utilizations; • Assign advanced exergoeconomic cost rates of the entire engine and sections by breaking them down to unavoidable/avoidable and exogenous/endogenous portions; • Check the advanced exergoeconomic cost rates for both kerosene and hydrogen fuel utilizations; • Reveal the sections that can be ameliorated by calculating economic benefit of amelioration potential (EBAP) for JP-8 and H 2 fuels.

Specification of TJE
(J85-GE-5H) TJE has high impulse and lightness characteristics provided by the integrated eight-level axial compressor and two-level axial turbine. The compressor (AC) and gas turbine (GT) consist of rotor (moving) and stator (fixed) blades. Rows of rotor and stator fins form a stage. There are six cellular-circular combustion chambers (CC) between the AC and the GT. The second part, where post-combustion occurs, is called the afterburner exhaust duct (ABED). The burning process The technical parameters are demonstrated as follows: The power output was reckoned with the values of 5106 and 8575 kW for the MIL and AB PM, seriatim [63]. The take-off thrust is 25.80 kN, the outside diameter of the TJE is 0.52 m, the engine length is 2.75 m, the engine weight is 265 kg, the flight speed range is 301-1004 m/s, the maximum operating altitude is 45,000 ft and the starting altitude range is 0-25,000 ft [64].
In this study, a cost analysis of J85-GE-5H TJE, used in T-38 training aircraft, was assessed with regards to its thermodynamic and thermoeconomic aspects. In this context, exergy-based sustainability, exergoeconomic and advanced exergoeconomic analyses of the engine were executed by considering the calculated costs in line with the data obtained from the engine test unit. The experimental throughput has been displayed in the control unit in order to trace values such as pressure (P), mass rates ( . m) and temperature (T), which have been obtained by indicators attached on the TJE. As the engine worked in the engine test cell, the inlet duct was not taken into account in the analysis [63]. The physicochemical properties of JP-8 and H 2 are indicated as follows: The kerosene fuel consists of approximately 9% C 8 -C 9 aliphatic hydrocarbons, 65% C 10 -C 14 aliphatic hydrocarbons, 7% C 15 -C 17 [66]. The air entering the engine is pressurized in the compressor section and passes to the combustion chamber section. Here, the mixture formed with pulverized sprayed JP-8 jet fuel is burned with spark plugs. The burnt gases expand in the GT and create mechanical work. While some of the mechanical work provides the movement of the AC and other engine accessories by rotating the mechanical shaft, the remaining part provides the necessary thrust for the flight. An extra impulse that may be needed depending on the flight characteristic is achieved by burning the sprayed AB fuel with the combustion gases in the ABED section. A basic cross section of TJE and the flow directions of air and gases are shown in Figure 1. The technical parameters are demonstrated as follows: The power output was reckoned with the values of 5106 and 8575 kW for the MIL and AB PM, seriatim [63]. The take-off thrust is 25.80 kN, the outside diameter of the TJE is 0.52 m, the engine length is 2.75 m, the engine weight is 265 kg, the flight speed range is 301-1004 m/s, the maximum operating altitude is 45,000 ft and the starting altitude range is 0-25,000 ft [64].
In this study, a cost analysis of J85-GE-5H TJE, used in T-38 training aircraft, was assessed with regards to its thermodynamic and thermoeconomic aspects. In this context, exergy-based sustainability, exergoeconomic and advanced exergoeconomic analyses of the engine were executed by considering the calculated costs in line with the data obtained from the engine test unit. The experimental throughput has been displayed in the control unit in order to trace values such as pressure (P), mass rates ( m  ) and temperature (T), which have been obtained by indicators attached on the TJE. As the engine worked in the engine test cell, the inlet duct was not taken into account in the analysis [63]. The physicochemical properties of JP-8 and H2 are indicated as follows: The kerosene fuel consists of approximately 9% C8-C9 aliphatic hydrocarbons, 65% C10-C14 aliphatic hydrocarbons, 7% C15-C17 aliphatic hydrocarbons and 18% aromatics with molecular weight: ≈ 180, synonyms: JP-8, freezing point maximum: −47 °C, boiling point: 175-300 °C, vapor pressure: 0.52 mm Hg (10 °C), 1.8 mm Hg (28 °C), specific gravity: minimum: 0.775 kg/L (15 °C), maximum: 0.840 kg/L (15 °C), the lower heating value (LHV) 119,450 kJ/kg and viscosity: 8 10 −6 kg/(m·s) (−20 °C) [65]. The liquefied hydrogen consists of two hydrogen atoms with molecular weight: 2.0159, synonyms: H2, melting point: −259.35 °C, boiling point: −252.88 °C, the LHV 43,124kJ/kg, density (gas): 0.08988 g/L (0 °C, 1 atm) and density (liquid): 70.8 g/L (at −253 °C) [66]. The air entering the engine is pressurized in the compressor section and passes to the combustion chamber section. Here, the mixture formed with pulverized sprayed JP-8 jet fuel is burned with spark plugs. The burnt gases expand in the GT and create mechanical work. While some of the mechanical work provides the movement of the AC and other engine accessories by rotating the mechanical shaft, the remaining part provides the necessary thrust for the flight. An extra impulse that may be needed depending on the flight characteristic is achieved by burning the sprayed AB fuel with the combustion gases in the ABED section. A basic cross section of TJE and the flow directions of air and gases are shown in Figure 1.

The Flow Process of the Analyses
The main flow process of the analyses is charted as shown in Figure 2.

The Flow Process of the Analyses
The main flow process of the analyses is charted as shown in Figure 2. The process starts with the definition of the process and ends up with the analyses of the outcomes of the study.

Assumptions Made
The listed assumptions are given as follows: • Calculations for air and burnout gases were considered with the ideal gas assumption.

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The TJE operated under constant conditions. • The fully burned gases were gained upon the completion of the operation. • Not only in kinetic exergy but also in potential exergy, no changes occur.

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The inlet velocity (Vin) was considered zero because of the constant test conditions. • The heat transfer ratios in AC and GT sections were regarded adiabatic [6,15].

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Kerosene and hydrogen are taken into account as fuels in this research.

Exergy Analysis
Exergy, an effective appliance, uses not only the second law of thermodynamics, but also the principles of mass and energy conservation. Exergy makes it possible to use the energy resources more efficiently by considering the best performance of the gas turbine systems because it can state the site and amount of wastes. In other words, the consumption of exergy leads to an entropy production as an output of the irreversible processes in a system. The general balance equation regarding the exergy is expressed as follows: x E  represent the ratio of heat transfer at n T temperature, the ratio of work, the flow ratio of exergy and the ratio of exergy destruction, seriatim. The equation regarding the exergy can be expressed as follows [15,41,42]: represent the ratio of fuel exergy and the ratio of product exergy, seriatim.
The L x E  and C x E  represent the exergy losses and exergy consumption, seriatim. The sum of [6,63]:

Evaluate analyses results
Determine and solve advanced exergoeconomic equations Determine and solve exergy, sustainability and exergoeconomic performance parameters Define and solve exergy and cost balance equations The process starts with the definition of the process and ends up with the analyses of the outcomes of the study.

Assumptions Made
The listed assumptions are given as follows: • Calculations for air and burnout gases were considered with the ideal gas assumption.

•
The TJE operated under constant conditions. • The fully burned gases were gained upon the completion of the operation. • Not only in kinetic exergy but also in potential exergy, no changes occur.

•
The inlet velocity (V in ) was considered zero because of the constant test conditions. • The heat transfer ratios in AC and GT sections were regarded adiabatic [6,15].

•
Kerosene and hydrogen are taken into account as fuels in this research.

Exergy Analysis
Exergy, an effective appliance, uses not only the second law of thermodynamics, but also the principles of mass and energy conservation. Exergy makes it possible to use the energy resources more efficiently by considering the best performance of the gas turbine systems because it can state the site and amount of wastes. In other words, the consumption of exergy leads to an entropy production as an output of the irreversible processes in a system. The general balance equation regarding the exergy is expressed as follows: Ex and .
Ex D represent the ratio of heat transfer at T n temperature, the ratio of work, the flow ratio of exergy and the ratio of exergy destruction, seriatim.
The equation regarding the exergy can be expressed as follows [15,41,42]: where .

Ex F and .
Ex Pr represent the ratio of fuel exergy and the ratio of product exergy, seriatim. The Ex C [6,63]: Energies 2020, 13, 3823 5 of 27

Conventional Exergoeconomic Analysis
The method of exergy analysis is utilized to assess thermodynamically the inefficiencies arising from irreversible processes. The assessment of the inefficiencies in the system by assigning cost values expresses the economic dimension of engineering analysis. The analysis method, which deals with the engineering analysis of the system integrated with exergy-based thermodynamic and economic analysis, is called exergoeconomic analysis. Exergoeconomic analysis takes into account all the expenditures made during the life cycle starting from the design phase of the system. It provides an extensive assessment opportunity. The types of costs can be determined by the exergoeconomic analysis method with (i) investment costs, (ii) maintenance and operating costs, (iii) exergy destruction costs and (iv) exergy loss costs [4,48,50]. There is more than one method in the literature related to the exergoeconomic analysis. The Specific Exergy Cost (SPECO) method was applied in this research. This method involves determining the exergy flows inserting and outgoing the process and solving equilibrium equations and related auxiliary equations created for unit exergy cost value analysis [35]. With this scope, the hourly levelized cost methodology has been chosen and the regarding equations have been demonstrated in Table 1 [48,49,51,52].

Unit Equation Equation No
The cost rate of exergy flow, The hourly rate of total investment cost, The hourly rate of the TJE's maintenance cost, The hourly rate of maintenance cost, The hourly rate of the TJE's investment cost, The equations regarding the TJE and its sections' hourly cost rate method algorithms are given in Table 2.

Description Unit Equation Equation No
The TJE's present worth, PW TJE ($) The TJE's present value factor, PVF (-) The TJE's yearly capital cost rate, A Capital recovery factor, CRF (-) The cost rate of yearly fuel, The TJE's hourly fuel cost rate,

Economic Data
The TIC TJE and OM .
C TJE values of the TJE are 1,200,000 $ and 72,000 $/yr, seriatim [64]. The yearly working time of the system, the interest rate, the salvage value rate and the engine lifetime are assumed to be 300 h/yr, 10%, 15% and 15 years, seriatim. While the selling price of JP-8 is considered 0.572 $/kg [64], it is considered to be 5.5 $/kg for H 2 fuel [52]. The  Table 3. Tables A1 and A2 indicate the rates of energy, exergy, mass flow, pressure and specific heat capacity for the TJE sections, seriatim, in Appendix A [63]. The equations respecting exergy and cost balance are denoted in Table 4. The TJE's hourly fuel cost rate,

Economic Data
The TJE TIC and TJE C OM  values of the TJE are 1,200,000 $ and 72,000 $/yr, seriatim [64]. The yearly working time of the system, the interest rate, the salvage value rate and the engine lifetime are assumed to be 300 h/yr, 10%, 15% and 15 years, seriatim. While the selling price of JP-8 is considered 0.572 $/kg [64], it is considered to be 5.5 $/kg for H2 fuel [52]. The  Table 3.
Tables A1 and A2 indicate the rates of energy, exergy, mass flow, pressure and specific heat capacity for the TJE sections, seriatim, in Appendix A [63]. The equations respecting exergy and cost balance are denoted in Table 4. Table 3. The TJE and its sections' cost of equipment and the hourly cost rates.

Economic Data
The TJE TIC and TJE C OM  values of the TJE are 1,200,000 $ and 72,000 $/yr, seriatim [64]. The yearly working time of the system, the interest rate, the salvage value rate and the engine lifetime are assumed to be 300 h/yr, 10%, 15% and 15 years, seriatim. While the selling price of JP-8 is considered 0.572 $/kg [64], it is considered to be 5.5 $/kg for H2 fuel [52]. The  Table 3.
Tables A1 and A2 indicate the rates of energy, exergy, mass flow, pressure and specific heat capacity for the TJE sections, seriatim, in Appendix A [63]. The equations respecting exergy and cost balance are denoted in Table 4. Table 3. The TJE and its sections' cost of equipment and the hourly cost rates.

Economic Data
The TJE TIC and TJE C OM  values of the TJE are 1,200,000 $ and 72,000 $/yr, seriatim [64]. The yearly working time of the system, the interest rate, the salvage value rate and the engine lifetime are assumed to be 300 h/yr, 10%, 15% and 15 years, seriatim. While the selling price of JP-8 is considered 0.572 $/kg [64], it is considered to be 5.5 $/kg for H2 fuel [52]. The  Table 3.
Tables A1 and A2 indicate the rates of energy, exergy, mass flow, pressure and specific heat capacity for the TJE sections, seriatim, in Appendix A [63]. The equations respecting exergy and cost balance are denoted in Table 4. Table 3. The TJE and its sections' cost of equipment and the hourly cost rates. (AC)

SEC.
The TJE's hourly fuel cost rate,

Economic Data
The TJE TIC and TJE C OM  values of the TJE are 1,200,000 $ and 72,000 $/yr, seriatim [64]. The yearly working time of the system, the interest rate, the salvage value rate and the engine lifetime are assumed to be 300 h/yr, 10%, 15% and 15 years, seriatim. While the selling price of JP-8 is considered 0.572 $/kg [64], it is considered to be 5.5 $/kg for H2 fuel [52]. The  Table 3.
Tables A1 and A2 indicate the rates of energy, exergy, mass flow, pressure and specific heat capacity for the TJE sections, seriatim, in Appendix A [63]. The equations respecting exergy and cost balance are denoted in Table 4. Table 3. The TJE and its sections' cost of equipment and the hourly cost rates. (AC)

Exergy and Exergoeconomic Performance Metrics
The performance metrics of the TJE respecting exergy, sustainability and exergoeconomic are assigned in Table 5 Energies 2020, 13, x FOR PEER REVIEW 7 of 28 (TJE-AB)

Exergy and Exergoeconomic Performance Metrics
The performance metrics of the TJE respecting exergy, sustainability and exergoeconomic are assigned in Table 5 Energies 2020, 13, x FOR PEER REVIEW 7 of 28 (TJE-AB)

Exergy and Exergoeconomic Performance Metrics
The performance metrics of the TJE respecting exergy, sustainability and exergoeconomic are assigned in Table 5 (TJE-AB) .

Description Unit Equation Equation No
Exergy efficiency, ψ .
Sustainability effect factor, SEF Sustainability cost index, SCI Unit exergy cost rate of product, c Pr ($/GJ) Economic benefit of amelioration potential rate, Total cost rate of the TJE, Exergy loss cost rate, Exergy destruction cost rate, Exergy consumption cost rate, Exergoeconomic factor, ξ n (%) In accordance with Tables A1 and A2, Tables 6 and 7 demonstrate the rate of exergy, the cost rates of exergy flow and the unit exergy as per the flow state numbers, respectively. Table 6. Values for the cost rates of exergy flow and unit exergy related to process sections for kerosene fuel use (*: exclusively AB PM).  Table 7. Values for the cost rates of exergy flow and unit exergy related to process sections for hydrogen fuel use (*: exclusively AB PM).

Advanced Exergy Analysis
Thanks to traditional exergy analysis, unproductiveness in the process is numerically obtained. Irreversible processes and losses with real development potential can be reduced by implementing advanced exergy analysis. The place and enormousness of the sources causing thermodynamic deficiencies can be described via traditional exergy analysis. It also evaluates process sections with the ultimate exergy destruction in general. The efficiency of the system sections can be ameliorated by mitigating the exergy demolition rates inside the sections. A conventional exergy analysis evaluates the process performance beneath certain operating circumstances in order to improve a step or section. However, it cannot take into account the best performance actually available from the system. It is not possible to predict the exergy amelioration capacity without considering section coactions with the conventional exergy analysis methods. These coactions, which cannot be evaluated by traditional exergy analysis, could be analyzed at length by considering the method of advanced exergy analysis [67,68]. Exergy destruction of each section, shown in Figure 3, is allocated to avoidable, unavoidable, exogenous and endogenous fragments.
Energies 2020, 13, x FOR PEER REVIEW 9 of 28 the ultimate exergy destruction in general. The efficiency of the system sections can be ameliorated by mitigating the exergy demolition rates inside the sections. A conventional exergy analysis evaluates the process performance beneath certain operating circumstances in order to improve a step or section. However, it cannot take into account the best performance actually available from the system. It is not possible to predict the exergy amelioration capacity without considering section coactions with the conventional exergy analysis methods. These coactions, which cannot be evaluated by traditional exergy analysis, could be analyzed at length by considering the method of advanced exergy analysis [67,68]. Exergy destruction of each section, shown in Figure 3, is allocated to avoidable, unavoidable, exogenous and endogenous fragments. The destruction respecting the endogenous division involves the section performance taking account that the leftover sections operate in optimum circumstances. The impact of the left-behind sections on the entire process forges the exogenous division of the destruction. The exergy destructions are divided into unavoidable and avoidable parts when considering the disposal capacity of irreversible processes. Though the new technologic improvements are implemented on The destruction respecting the endogenous division involves the section performance taking account that the leftover sections operate in optimum circumstances. The impact of the left-behind sections on the entire process forges the exogenous division of the destruction. The exergy destructions are divided into unavoidable and avoidable parts when considering the disposal capacity of irreversible processes. Though the new technologic improvements are implemented on the systems, the unavoidable division of the sections cannot be eliminated. Nevertheless, the avoidable division can be recovered per technical amelioration. Further analysis of the system can be achieved by combining the . Ex D rates. The equations respecting advanced exergy are demonstrated in Table 8 [68][69][70][71][72][73]: Unavoidable-endogenous exergy destruction,

Advanced Exergoeconomic Analysis
The process evaluation in terms of cost is firstly executed via exergoeconomic analysis. Then, the results obtained from traditional exergoeconomic analysis are broken down into unavoidable, endogenous, avoidable and exogenous divisions for further assessment not only for the cost of exergy conditions. Evaluating the interactions of all system components on each other and the improvement potential of each section is important for cost improvement. The unavoidable investment cost UN n Z  refers to the inevitable cost of the section. UN n TIC is the unavoidable cost of the purchased section that cannot be reduced due to the manufacturing restricts [54][55][56][57][58][59][60][61][62]. A schematic subdivision respecting   Table 9. Table 9. Advanced exergoeconomic equations of investment and exergy destruction costs [55].   Table 9. Table 9. Advanced exergoeconomic equations of investment and exergy destruction costs [55].

Results and Discussion
In accordance with Tables 6 and A1, while exergetic and exergoeconomic performance metrics are shown with the use of kerosene in Table 10 for MIL PM, they are demonstrated in Table 11 [63]. The lowest SEF was reckoned in the CC section with the rate of 2.20 for the MIL PM, while it was computed to be 2.13 in the ABED section for the AB PM. The ultimate SCI were calculated in the CC section with the rate of 20.43 $/GJ both for the AB and MIL PM. The utmost EBAP was reckoned in the CC as 154 $/h for the MIL PM, while it was computed with a rate of 644 $/h for the AB PM. Figure 5 indicates the TJE and its sections' EBAP rates with kerosene fuel use.  Table 11. Results for exergy, exergoeconomic and sustainability performance indicators for AB PM with kerosene fuel use.

Ex Pr (kW)
. seriatim. The TJE's exergetic efficiency was determined 16.98% and 30.85% for the AB and MIL PM, seriatim [63]. The lowest SEF was reckoned in the CC section with the rate of 2.20 for the MIL PM, while it was computed to be 2.13 in the ABED section for the AB PM. The ultimate SCI were calculated in the CC section with the rate of 20.43 $/GJ both for the AB and MIL PM. The utmost EBAP was reckoned in the CC as 154 $/h for the MIL PM, while it was computed with a rate of 644 $/h for the AB PM. Figure 5 indicates the TJE and its sections' EBAP rates with kerosene fuel use. The overall SEF of the engine was computed 1.20 and 1.45 for AB and MIL PM, seriatim, while SCI was reckoned with the rates of 78.84 and 52.86 $/GJ. In accordance with the ameliorated potential of the system, the EBAP was determined to be 356 and 1565 $/h for MIL and AB PM, seriatim. The maximum . Z TIC was calculated with the rate of 209 $/h in AC section, whereas it was reckoned at 13.76 $/h in the GTMS section with the minimum rate for both aforementioned modes. As per Table 6, . C TJE was reckoned at 1405 $/h for the MIL PM, while it was calculated to be 2932 $/h for AB PM. According to Figure 6, the π and the ζ of the entire process were determined 512% and 56.20% for the MIL PM, whereas they were computed 660% and 25.95% for the AB PM, seriatim. The cost ratios and the indicators of the sustainability and exergy related to the engine sections are demonstrated below.  The overall SEF of the engine was computed 1. 20  According to Figure 6, the π and the ζ of the entire process were determined 512% and 56.20% for the MIL PM, whereas they were computed 660% and 25.95% for the AB PM, seriatim. The cost ratios and the indicators of the sustainability and exergy related to the engine sections are demonstrated below.

Ex C (kW) ψ(%) SEF(−) SCI($/GJ) EBAP($/h) c F ($/GJ) c Pr ($/GJ
With respect to  With respect to Table 10, the maximum unit fuel cost rate was calculated in the AC section, which had a rate of 59.39 $/GJ, while it was reckoned at 12.49 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with the rate of 82.91 $/GJ, while it was calculated to be 76.45 $/GJ for the whole engine. The utmost . C C and the π were determined at 338 $/h and 260% in the CC section, seriatim, while they were reckoned at 515 $/h and 512% for the whole engine. Therewithal, CC section had the minimum ζ with 28.91%.
With respect to Table 11, the ultimate unit fuel cost rate was calculated in the AC section, which had a rate of 59.39 $/GJ, while it was reckoned at 12.49 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with a rate of 82.91 $/GJ, while it was calculated to be 94.97 $/GJ for the entire engine. The utmost . C C was determined at 1360 $/h in the ABED section, while it was reckoned at 1886 $/h for the whole engine. In addition, ABED section had the minimum ζ with 4.63%.
In accordance with Tables 7 and A2, while exergetic and exergoeconomic performance metrics are shown with the use of hydrogen in Table 12 for MIL PM, they are demonstrated in Table 13 [63]. The lowest SEF was reckoned in the CC section with a rate of 2.08 for the MIL PM, while it was computed to be 1.89 in the ABED section for the AB PM. The ultimate SCI were calculated in the CC section with a rate of 53.89 $/GJ for the MIL PM, while it was computed at 61.17 $/GJ for AB PM. The utmost EBAP was reckoned in the CC with a rate of 600 $/h for the MIL PM, while it was computed to be at a rate of 2372 $/h for the AB PM. Figure 7 indicates the EBAP of the TJE and its sections with the usage of H 2 fuel.
Energies 2020, 13, x FOR PEER REVIEW 14 of 28 With respect to Table 11, the ultimate unit fuel cost rate was calculated in the AC section, which had a rate of 59.39 $/GJ, while it was reckoned at 12.49 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with a rate of 82.91 $/GJ, while it was calculated to be 94.97 $/GJ for the entire engine. The utmost C C  was determined at 1360 $/h in the ABED section, while it was reckoned at 1886 $/h for the whole engine. In addition, ABED section had the minimum ζ with 4.63%.
In accordance with Tables A2 and 7, while exergetic and exergoeconomic performance metrics are shown with the use of hydrogen in Table 12 for MIL PM, they are demonstrated in Table 13 [63]. The lowest SEF was reckoned in the CC section with a rate of 2.08 for the MIL PM, while it was computed to be 1.89 in the ABED section for the AB PM. The ultimate SCI were calculated in the CC section with a rate of 53.89 $/GJ for the MIL PM, while it was computed at 61.17 $/GJ for AB PM. The utmost EBAP was reckoned in the CC with a rate of 600 $/h for the MIL PM, while it was computed to be at a rate of 2372 $/h for the AB PM. Figure 7 indicates the EBAP of the TJE and its sections with the usage of H2 fuel. The overall SEF of the engine was computed to be 1.18 and 1.40 for AB and MIL PM, seriatim, while SCI was reckoned with rates of 128 and 244 $/GJ. In accordance with the ameliorated potential of the system, the EBAP was determined to be 1317 and 5652 $/h for MIL and AB PM, seriatim. The maximum TIC Z  was calculated with a rate of 209 $/h in the AC section, whereas it was reckoned at 13.76 $/h in GTMS section with the minimum rate for both aforementioned PMs. As per Table 7, TJE C  was reckoned at 3245 $/h for MIL PM, while it was calculated to be 8545 $/h for AB PM. As per Figure 8, the π and the ζ of the entire system were determined to be 339% and 26.37% for the MIL PM, whereas they were computed to be 607% and 9.01% for the AB PM, seriatim. The cost rates and the indicators of sustainability and exergy related to engine sections are demonstrated in Figure 8.   Table 13. Results for exergy, exergoeconomic and sustainability performance indicators for AB PM with hydrogen fuel use.

IP($/h) c F ($/GJ) c Pr ($/GJ
The maximum . Z TIC was calculated with a rate of 209 $/h in the AC section, whereas it was reckoned at 13.76 $/h in GTMS section with the minimum rate for both aforementioned PMs. As per Table 7, . C TJE was reckoned at 3245 $/h for MIL PM, while it was calculated to be 8545 $/h for AB PM. As per Figure 8, the π and the ζ of the entire system were determined to be 339% and 26.37% for the MIL PM, whereas they were computed to be 607% and 9.01% for the AB PM, seriatim. The cost rates and the indicators of sustainability and exergy related to engine sections are demonstrated in Figure 8. With respect to Table 12, the ultimate unit fuel cost rate was calculated in the AC section, which had a rate of 136 $/GJ, while it was reckoned at 40.81 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with a rate of 174 $/GJ, while it was calculated to be 179 $/GJ for the whole engine. The utmost C C  and the π were determined to be 1245 $/h and 174% in the CC section, seriatim, while they were reckoned at 1845 $/h and 339% for the whole engine. Therewithal, the CC section had the minimum ζ with 9.95%. With respect to Table 12, the ultimate unit fuel cost rate was calculated in the AC section, which had a rate of 136 $/GJ, while it was reckoned at 40.81 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with a rate of 174 $/GJ, while it was calculated to be 179 $/GJ for the whole engine. The utmost . C C and the π were determined to be 1245 $/h and 174% in the CC section, seriatim, while they were reckoned at 1845 $/h and 339% for the whole engine. Therewithal, the CC section had the minimum ζ with 9.95%.
With respect to Table 13, the ultimate unit fuel cost rate was calculated in the AC section, which had a rate of 136 $/GJ, while it was reckoned at 40.81 $/GJ for the entire engine. Moreover, the AC section had the ultimate unit product cost with a rate of 174 $/GJ, while it was calculated to be288 $/GJ for the entire engine. The ultimate π was assigned in the CC and ABED sections as 174% and 114%, seriatim. The ultimate . C C was determined 4488 $/h in the ABED section, while it was reckoned at 6676 $/h for the whole engine. At the same time, ABED had the minimum ζ with 1.45%.
The comparative consequences of this research according to Figure 9 with the J85-GE-CAN-15 TJE research [49] are discussed as follows: Energies 2020, 13, 3823 16 of 27 121 $/GJ and 1040 $/h for MIL PM, respectively, while they were reckoned as 4079 $/h, 133 $/GJ and 3150 $/h for AB PM with kerosene fuel utilization. Moreover, while the SEF were calculated to be1.42 and 1.29 for the MIL and AB PM, seriatim, the SCI were reckoned at 85.26 and 103 $/GJ. As per Figure  9, the results indicate that the J85-GE-5H TJE for the present study is more cost effective than the J85-GE-CAN-15 TJE. From another research perspective, as per [52], the comparatively. In accordance with Table 9, the outcomes of the exergoeconomic analysis are confirmed with the results of the advanced exergoeconomic analysis. While the advanced investment costs are demonstrated in Table 14, the exergoeconomic destruction costs are indicated in Table 15 for JP-8 usage.

TJE-AB
The unit product cost rate of TJE ($/GJ) C F , the c Pr and the . C C of J85-GE-CAN-15 TJE engine were determined to be 1482 $/h, 121 $/GJ and 1040 $/h for MIL PM, respectively, while they were reckoned as 4079 $/h, 133 $/GJ and 3150 $/h for AB PM with kerosene fuel utilization. Moreover, while the SEF were calculated to be1.42 and 1.29 for the MIL and AB PM, seriatim, the SCI were reckoned at 85.26 and 103 $/GJ. As per Figure 9, the results indicate that the J85-GE-5H TJE for the present study is more cost effective than the J85-GE-CAN-15 TJE.
From another research perspective, as per [52], the . C F , the c Pr and the . C C of the (J69-T-25A) TJE engine were determined to be 1144 $/h, 355 $/GJ and 980 $/h, respectively, with H 2 fuel use. Although the exergetic efficiency of the J69 TJE was less than the one in this study, the J85-GE-5H TJE's .

C TJE
was reckoned higher than the J69 TJE due to the higher rates of the . C F and the . Z TIC comparatively. In accordance with Table 9, the outcomes of the exergoeconomic analysis are confirmed with the results of the advanced exergoeconomic analysis. While the advanced investment costs are demonstrated in Table 14, the exergoeconomic destruction costs are indicated in Table 15 for JP-8 usage.        Table 16 and the exergoeconomic destruction costs are displayed in Table 17.

Conclusions
J85-GE-5H TJE was evaluated completely considering exergoeconomic and advanced exergoeconomic analyses with kerosene and hydrogen fuels usage. Primarily, sustainability, exergoeconomic and advanced exergoeconomic analyses of the TJE were fulfilled utilizing kerosene fuel with respect to real engine working circumstances. The aforementioned analyses were then perused parametrically in terms of using H 2 fuel. After all, the outcomes reckoned for both fuel uses were collated in terms of cost effectiveness assessment of the TJE. The main conspicuous sequels related to the current research were stated below: • The ζ rates were computed as 56.20% and 25.95% for the MIL and AB PM with kerosene use, seriatim. By taking into account the use of H 2 , the ζ were 26.37% and 9.01%.

•
The π rates were calculated to be 512% for the MIL PM and 660% for the AB PM. By considering the use of hydrogen, the π were 339% and 607%, seriatim.

•
The SEF values were determined to be 1. 45   cost rate in the whole tract not only for kerosene use but also for H 2 use.
Between the system sections, the CC and ABED had the maximum . C D , . C UN D , SCI, π and EBAP rates for both fuel usages, whereas they had the minimum ζ and SEF rates. These results demonstrated that the primary factor bringing about an increase in the cost rates was the high demolition cost values of the CC and ABED sections because of the imperfections that happened in the combustion process. Meanwhile, the utmost avoidable investment costs were determined in the AC, CC and GT sections, whereas the utmost avoidable exergy destruction costs were reckoned in the ABED, AC and CC sections because of the relatively great exergy destructions rates. When the analyses are examined in terms of the internal state of the section, it was revealed that the potential for improvement depended mostly on sections. Hence, the endogenous demolition cost rate was larger than the exogenous demolition cost rate. The results were also similar for the cost rates of investment in terms of advanced analysis. The aforementioned analyses indicated that the sections were in the boundary of thermodynamic restraints as per the . Z UNEN and the . C UNEN D rates and had to be produced to obtain better performance not only in thermodynamic efficiency but also in cost effectiveness. Therefore, the researchers have been studying to enhance the performance of TJE by implementing innovations such as three-dimensional (3D) print manufacturing technologies, which lessen the labor, material and development cost rates drastically.
Consequently, the engine operated less cost effective with the use of H 2 because of the increase in . C D . Moreover, it was less sustainable due to the lower efficiency. Although the renewable energy sources will take the place of oil resources in the future, there has to be done to pave the way of production technologies to alter the challenges both in efficiency and cost effectiveness in gas turbine systems. Funding: This study received no external funding.

Acknowledgments:
The authors are very grateful to the three reviewers and Assistant Editor for their constructive and valuable suggestions, which helped increase the quality of the paper.

Conflicts of Interest:
The authors declare no conflict of interest.   Mechanical work ----5583 5583 Table A3. Results for endogenous, exogenous, unavoidable and avoidable exergy demolition of the TJE and its sections for the MIL process mode for JP-8 utilization [63].