Thermal Performance Index Research Articles

Effects of oscillation frequency, phase difference, and arrangement of two triangular cylinders on the hydrothermal performance of a channel

This study aims to numerically explore the effects of two cylinders with triangular cross sections, undergoing transverse oscillation on the heat and fluid flow within a channel. The governing equations along with the pertinent initial and boundary conditions are solved using the finite element method. The results are validated against the available data in the literature, demonstrating admissible agreement. Different oscillation frequencies, phase differences, and arrangement of the cylinders are considered. The results are presented in terms of temperature, pressure, and vorticity contours, alongside the Nusselt (Nu) number and thermal performance index (TPI). The Reynolds number based on the triangle's side length (Reb=200) is deliberately chosen to induce the vortex shedding phenomenon in the wake of the cylinders. For a single oscillatory cylinder, an optimal oscillation frequency fr=0.5 was found resulting in a remarkable increase in 22.3% and 33.1% in the Nu number and TPI, respectively, when compared to the fixed single cylinder. Using the obtained optimal oscillation frequency fr=0.5, the side-by-side arrangement of two cylinders gives rise to a higher TPI than the tandem one. The maximum TPI in side-by-side arrangement corresponds to the oscillation phase of φ=π/6, which is about 1.69. In tandem arrangement, it corresponds to φ=π/3, which is approximately 1.3. Furthermore, the oscillation phase φ=π exhibits the lowest TPI for both arrangements.

Experimental and machine learning insights on heat transfer and friction factor analysis of novel hybrid nanofluids subjected to constant heat flux at various mixture ratios

This study explores the combined effects of aluminum oxide (Al₂O₃)/graphene oxide (GO) hybrid nanofluids in 50:50 and 80:20 ratios, offering a notable improvement over conventional Al₂O₃ or GO nanofluids. It delivers a thorough comparison of thermophysical properties such as thermal conductivity and viscosity and heat transfer performance across water, Al₂O₃ nanofluids, and the Al₂O₃/GO hybrids. Nanofluids at 0.1–0.5 % volume concentrations were tested in a horizontal circular pipe under constant heat flux and turbulent flow with an inlet temperature of 60 °C. The maximum Nu enhancements of 64, 56 and 41 % were noted for Al₂O₃/GO (50:50), Al₂O₃/GO (80:20), and Al₂O₃ nanofluids, respectively at 0.5 vol%, compared to water. The maximum pressure drop of Al2O3/GO (50:50) nanofluid is 5.64 and 8.3 % greater than that of Al2O3/GO (80:20) and Al2O3 nanofluid, respectively at 0.5 vol%. The peak thermal performance index of 1.56, 1.48, and 1.33 is observed for Al₂O₃/GO (50:50), Al₂O₃/GO (80:20), and Al₂O₃ nanofluids. The integration of a multi-layer perceptron artificial neural network further enhances accuracy in predicting thermal performance, surpassing the precision of conventional empirical models. The adopted model showed excellent predictive accuracy, with correlation coefficients of 0.98493 in training, 0.9837 in validation, and 0.98698 in testing.

Proposing design strategies for contemporary courtyards based on thermal comfort in cold and semi-arid climate zones

The relationship between urban geometry and microclimate is crucial in urban planning and climatology, significantly affecting outdoor comfort and energy consumption. Compact, dense buildings provide shading in summer, while openness is preferred in winter to maximize sunlight access. Courtyards, as climate-responsive structures, can create localized microclimates tailored to specific climatic conditions. Various components, including geometry, openness, orientation, wall materials, and green cover, influence the microclimate within a courtyard. While previous studies have primarily focused on hot and arid climates, there is a notable research gap concerning the thermal behavior of courtyards in cold and semi-arid regions. This study seeks to fill this gap by evaluating the impact of different courtyard geometries on outdoor thermal comfort specifically in semi-dry and cold climates by exploring optimal configurations for orientation, form, height-to-width ratios, and plan aspect ratios, the research offers strategies that improve both summer and winter microclimates. The study examined the combined effects of geometry and orientation on shading and wind speed in courtyards, modeling their influence on microclimates during warm summers and cold winters using ENVI-met software. Thermal performance indices, specifically PET and UTCI, were employed to assess the courtyards in Tehran. The findings reveal that a height-to-width ratio of 3:1 significantly improves thermal comfort, resulting in a UTCI difference of 19 °C. Furthermore, the model with a 2:1 plan aspect ratio exhibited a UTCI that was 6.7 °C lower than that of the 3:1 ratio. These findings provide valuable insights for designing contemporary courtyards that optimize thermal comfort in similar climates.

Thermal performance assessment of exterior building walls under intermittent air-conditioning operation in China's hot summer and cold winter zone

Optimizing the design and accurately assessing the performance of building envelopes are critical for substantially reducing energy use in the building sector. Existing studies on methods for evaluating the thermal performance of building envelopes have primarily focused on periodic unsteady conditions (often associated with continuous air-conditioning operation). This study aims to investigate the initial transient thermal performance of exterior building envelopes. Specifically, we examined varying insulation distributions considering the hot summer and cold winter zone of China as an example. To simulate real-world conditions, we developed a dynamic hot box facility that mimics both outdoor and indoor environments, enabling the measurement of key parameters of the dynamic thermal process of the wall. We evaluated the thermal response, energy performance, and heat storage metrics of the wall to understand the impact of the insulation distribution and air-conditioning operation modes on the thermal performance of opaque building walls. This assessment covered six intermittent operation stages—four construction structures and two types of building usage—for both summer and winter conditions. The proposed methodology provides a quantitative approach for assessing the dynamic thermal processes of the wall, with the results indicating that the heat transmission of walls during intermittent operation exhibited initial transient characteristics. As a result, thermal performance indices suitable for periodic unsteady conditions could not be directly applied to initial transient conditions. To address this issue, the metrics of daily mean dynamic thermal transmittance and daily mean dynamic thermal resistance were proposed and validated. These metrics accurately reflected the actual fluctuations in total transmission loads, thus providing an accurate rapid index-oriented method for assessing the energy-saving performance of walls. Overall, this study lays the groundwork for evaluating dynamic thermal behaviour of building envelopes.

Understanding Inconsistencies in Thermohydraulic Characteristics Between Experimental and Numerical Data for DI Water Flow Through a Rectangular Microchannel

Abstract Facing discrepancies between numerical simulation, experimental measurement, and theory is common in studies of fluid flow and heat transfer in microchannels. The cause of these discrepancies is often linked to the transition from the macroscale to the microscale, where the flow dynamics might be expected to deviate due to possible changes in dominant forces. In this work, an attempt is made to achieve agreement between experiment, numerical simulation, and theoretical description within the usual framework of laminar flow theory. For this purpose, the pressure drop, friction factor, and Poiseuille number under isothermal conditions and the temperature profile, heat transfer coefficient, Nusselt number, and thermal performance index under diabatic conditions (heating power of 10 W) in a heat sink with a stainless steel microchannel with a hydraulic diameter of 850 μm were investigated numerically and experimentally for mass flow rates between 1 and 68 gmin−1. The source of inconsistencies in pressure drop characteristics is found to be linked to the geometrical details of the utilized microchannel, for example, the design of inlet/outlet manifolds, the artifacts of manufacturing technique, and other features of the experimental test rig. For the heat transfer characteristics, it is identified that an appropriate estimation of the outer boundary condition for the numerical simulation remains the crucial challenge to obtain a reasonable agreement. The paper provides a detailed overview of how to account for these details to mitigate the discrepancies and to establish a handshake between experiments, numerical simulations, and theory.

Power-Law Nanofluid Magnetohydrodynamics Combined Convection in the Presence of Heat Absorption/Generation: A Lattice Boltzmann Analysis to Compute Thermal Performance Index

Endeavors to improve the performance of thermal systems have always been of great noticed due to their extremely high importance in industrial and engineering applications. For this intention, in the existing simulation, several effective strategies have been evaluated to determine the amount of heat transfer and entropy formation caused by the combined convection of non-Newtonian nanofluid with particles Brownian motion. Based on the findings via LBM simulation, it has been observed that changing the position and speed direction on the chamber wall helps to control the flow characteristics, and thus significantly changes the thermal performance of the system. The least effect of the magnetic field in reducing the value of the Nusselt number in all the positions of applying the speed belongs to the state where the wall direction is aligned with the force of gravity. In the case where the middle part of the vertical wall has speed, the formed flow power inside the chamber is 29% and 45% higher than when the first third and the last third of the wall have speed. The presence of a strong magnetic field leads to the reduction of convection effects, which is more evident for moving up the vertical wall. When the middle part of the wall has speed, if the magnetic field is applied to the middle part of the chamber to the highest value, the reduction of the average Nusselt number is about 35% and 39% more than the case when the magnetic field is applied to the first third and the last third of chamber. To have a higher average Nusselt number value, reducing the fluid power-law index and enhancing the Reynolds number value are effective strategies. To control the effects of the magnetic field, it is very effective to reduce the shear force on the chamber wall and expose the fluid flow to the heat absorption/production phenomenon. By reducing the value of fluid power-law index, the effect of magnetic field and heat absorption/production becomes more evident. In Re=200, the reduction of the thermal performance index for enhancing the Hartmann number value to the highest value is about 39% for n = 0.45, while this effect is about 31% and 24% for n = 0.7 and n = 0.95, respectively. By exposing the current to heat production, the effect of the magnetic field is reported to be about 55% higher than in other cases. Although heat production enhances the amount of Be value by about 66% compared to the heat absorption mode, it leads to an increase in the thermal performance index. The highest value of the system thermal performance index (0.82) can be achieved by upward moving the middle part of the chamber wall in the absence of magnetic field for heat absorption mode at the lowest power-law index and the highest Reynolds number value.

Developing a Practical Thermal Performance Index for Radiant Terminals—Structural Thermal Resistance

Radiant terminals have been widely applied in heating and cooling systems. However, few existing thermal performance evaluation indices can reflect the influence of structural forms on heat transfer performance. This study introduces the structural thermal resistance (Rs) to rapidly evaluate the structure form’s effects. First, theoretical analysis and experimental tests were introduced. Three types of terminals, including the copper conduit graphite plate (CCGP), plastic tube-embedded metal plate (PTMP), and capillary network-embedded structural plate (CNSP) were tested in the laboratory. Then, the CNSP terminals were taken as validation examples. The results show that the Rs values of the same type of radiant terminal tend to be stable and constant. The variations in Rs within the same type of radiant terminals were small both under cooling and heating conditions. Only when the terminal structure changed, the Rs would change. This suggests that the Rs can reflect the complex heat transfer processes inside the radiant terminals while distinguishing different terminal types. The validation analysis showed an average relative error of 3.4% and 2.9% for cooling and heating, respectively. Lastly, the potential application of Rs in practical applications was discussed, and a Python-based online tool was developed to help design, operate, and evaluate radiant terminals.

Thermal resistance analysis on conjugate free convective flow in a thick-walled square chamber

A numerical analysis of the conjugate free convective flow of air in a thick-walled square chamber has been conducted in this study. The finite left thick wall is heated with any of the four heating conditions, while the finite right thick surface is kept at a fixed cold temperature, and the remaining walls are assumed to be insulated. The governing equations are simulated via the Galerkin finite element technique with a triangular discretization scheme. Thermal resistance analysis is done for an extensive range of Rayleigh numbers (103 ≤ Ra ≤ 107) under four heating conditions of the left wall: isothermal, linear, sinusoidal, and isoflux. Besides, ten different combinations of wall thickness (0 ≤ t1/L ≤ 0.2 and 0 ≤ t2/L ≤ 0.2, where L is the length of the chamber) and three wall materials, such as glass fiber (ks = 0.035 W/mK), pinewood (ks = 0.15 W/mK), and plexiglass (ks = 0.195 W/mK), are considered in this parametric study. The effects of these parameters are presented in terms of the mean Nusselt number along the left solid-fluid interacting wall and the overall thermal performance index. In addition, qualitative visualization of heatlines, streamlines, and isotherms is illustrated for the optimum condition. Numerical results suggest that wall materials with higher thermal conductivity and lower wall thickness give the highest overall thermal performance for a linear heating condition.

A New Method of Building Envelope Thermal Performance Evaluation Considering Window–Wall Correlation

This study proposes a new method to accurately evaluate the overall building envelope thermal performance considering the window–wall correlation, providing a new tool for building thermal design. Firstly, a non-stationary room heat transfer model is established based on the Resistance-Capacity Network method. The influence of solar heat gain through the windows on the heat transfer process of the walls in the actual environment is considered, and the room’s integrated thermal resistance and integrated heat capacity indexes describing the overall room thermal resilience performance are proposed. Then, a field research test is conducted around Lhasa to obtain the local dwelling information, climate conditions, and indoor thermal environment. Numerical simulations using EnergyPlus are made to verify the effectiveness of the indexes in describing the overall building (maximum difference within 3.67% MBE and 2.92% CVRMSE) based on the field test results. Finally, the proposed envelope thermal performance index is used to analyze the local residential buildings around Lhasa. The results show that the lack of consideration of window–wall correlation has led to the failure of a local newly built building’s actual envelope performance to meet the design requirements. These findings could help to develop the thermal design method of the building envelope.

Study on flow and heat transfer characteristics in rectangular channels with lantern-shaped pin fin array: Part I- effect of sphere diameter

Featuring high heat transfer capacity and low pressure loss, pin fin arrays have become one of the important cooling methods for the trailing edge cooling channel of modern gas turbines. To improve the heat transfer efficiency of the channel, a lantern-shaped pin consisting of a cylinder and a sphere is proposed in Part I of this study. The flow and heat transfer characteristics in rectangular channels containing eight rows of staggered lantern-shaped pins with different sphere-to-pin diameter ratios, R/D, are investigated and compared by numerical simulations in the Re range of 3,000 to 30,000. The calculations indicate that the spheres trigger a pair of counter-rotating vortices behind the pins, which significantly enhance the Nusselt number and pressure loss. The pair of vortices also change the distributions of the endwall and pin Nusselt number. The endwall Nusselt numbers behind the fins and the pin Nusselt numbers at the leading edge and trailing edge of the pins are substantially enhanced. After the third row, the endwall Nusselt number augmentation Nu e/Nu 0 of the lantern-shaped pin with R/D = 1.0 decreases with the increased Re. However, the result of a slight increase in the Nu e/Nu 0 with the increased Re for R/D = 1.7 is diametrically opposite to that for R/D = 1.0. Meanwhile, with the increasing R/D, the separation and transition points are closer to the trailing edge. The increased Re makes the separation point moves closer to the leading edge while the transition point remains near 130 degrees. The endwall, pin, total area-averaged Nusselt numbers, and pressure loss rapidly boost with the increased R/D. The thermal performance index of the lantern-shaped pin with R/D = 1.7 ranges from 1.72 to 1.21. At Re = 10,000, the lantern-shaped pin with R/D = 1.7 shows the most significant percentage increase in thermal performance index of 4.39% compared to R/D = 1.0.

Thermal performance index based characterization and experimental validation for heat dissipation by unconventional arrayed micro pin-fins

Thermal performance index based characterization and experimental validation for heat dissipation by unconventional arrayed micro pin-fins

Augmenting the double pipe heat exchanger efficiency using varied molar Ag ornamented graphene oxide (GO) nanoparticles aqueous hybrid nanofluids

The optimization of heat transfer in heat exchanging equipment is paramount for the efficient management of energy resources in both industrial and residential settings. In pursuit of this goal, this empirical study embarked on enhancing the heat transfer performance of a double pipe heat exchanger (DPHX) by introducing silver (Ag)-graphene oxide (GO) hybrid nanofluids into the annulus of the heat exchanger. To achieve this, three distinct molar concentrations of Ag ornamented GO hybrid nanoparticles were synthesized by blending GO nanoparticles with silver nitrate at molarities of 0.03 M, 0.06 M, and 0.09 M. These Ag-GO hybrid nanoparticles were then dispersed in the base fluid, resulting in the formation of three distinct hybrid nanofluids, each with a consistent weight percentage of 0.05 wt%. Thorough characterization and evaluation of thermophysical properties were performed on the resulting hybrid nanomaterials and nanofluids, respectively. Remarkably, the most significant enhancement in heat transfer coefficient, Nusselt number, and thermal performance index (62.9%, 33.55%, and 1.29, respectively) was observed with the 0.09 M Ag-GO hybrid nanofluid, operating at a Reynolds number of 1,451 and a flow rate of 47 g/s. These findings highlight the substantial improvement in thermophysical properties of the base fluid and the intensification of heat transfer in the DPHX with increasing Ag molarity over GO. In summary, this study emphasizes the vital importance of optimizing the molarity of the material, which also plays a significant role in nanoparticle synthesis to achieve the optimal amplification of heat transfer.

Building envelope resilience to climate change under Italian energy policies

As a result of recent geopolitical events, zero-energy buildings must include a climate change prevention strategy. Policies are moving in the direction of an energy transition. Italian regulations, complying with European directives, are driving toward increasingly thermally insulated buildings. An important objective of this study is to determine whether updates to building energy efficiency regulations from 2005, particularly for the envelope, will result in increased envelope resilience to climate change. The building was analyzed without air conditioning, simulating an extreme case of a long period without gas supply. It has been located in all Italian climate zones and adapted to respect the local requirements imposed by national regulations for each climate zone. The legal requirements investigated are Italian Legislative Decree 192/2005, Italian Ministerial Decree 26/6/2015, and Italian Ministerial Decree 6/8/2020. The forecasting analyses were carried out considering the years 2030, 2050, and 2070 and three Representative Concentration Pathway scenarios (RCP 2.6, 4.5, and 8.5). The analysis of the results focused on trends of heating, cooling and total thermal performance index from the years 2030–2070. For all RCP scenarios, the 2015 and 2020 requirements optimize total envelope performance in terms of total thermal performance index and perform particularly well with the 2020 limits. It is clean that lowering the transmittance of the envelope components leads to an improvement in the total thermal performance index which, however, by maintaining the same trend over the years with the different scenarios, suggests that the resilience of the envelope to climate change is actually little affected by the transmittance value of the component structures.

Thermal performance evaluation of parabolic trough collector having different inserts and working with hybrid nanofluid

This study emphasizes the comparative investigation of the thermal capacity of parabolic solar trough collectors with spherical-shaped balls and two types of elliptical inserts (longitudinal orientation). Hybrid nanofluid is the heat-carrying liquid obtained by mixing CuO and Al2O3 nanoparticles in distilled water. Analytical investigations are conducted for 1% vol. concentration of hybrid nanoparticles in distilled water for varying proportions. Computational analysis is chosen to obtain thermal as well as flow trends in the tube receiver. The outcomes disclosed that 13.3%, 10.02%, and 16% improvements are noted for thermal efficiency, Nusselt number, and thermal performance index with elliptical inserts of minor diameter 12 mm in the receiver, respectively, than spherical ball inserts. The highest pump work of 35 W is associated with spherical inserts at 0.033 kg/s.

Utilizing artificial neural networks to predict the thermal performance of conical tubes with pulsating flow

A novel model of an artificial neural network is presented to predict friction factor and Nusselt number for pulsating flow in conically coiled tubes. The tubes are manufactured with coil torsions ranging between 0.02 and 0.052 and are subjected to a uniform heat flux. Experiments using pulsating flow with a pulsating frequency of 4 to 10Hz and a Reynolds number between 4836 and 12,562 were expanded. In terms of overall heat transfer improvement, the pulsing flow with a frequency of 4 Hz performs the best within the investigated range. Results demonstrated that the Nusselt number and thermal performance index increased when the Reynolds number and coil torsion decreased. The results predicted by a Feed-forward neural network were compared to the actual experimental data. A comparison showed that a feed-forward neural network could predict the Nusselt number and friction factor. The average root mean square error for the predicted Nusselt number was 4.6025. There is a good agreement between the predicted values and the experimental values. At the same Reynolds number and with a frequency of 4 Hz, reducing coil torsion from 0.052 to 0.02 improves Nusselt number by 23 % and 10 %, experimentally and in a feed-forward neural network, respectively.

Hybrid Heat Transfer Augmentation from Oscillating Cylinder with Partial Superhydrophobic Janus Surfaces

Flow over an oscillating cylinder has been the subject of various studies as well as its heat transfer characteristics due to the lock-in phenomenon which occurs as a result of multiple frequencies being present in the system. The motivation was to investigate the effect of superhydrophobicity on heat transfer and wake dynamics of partially superhydrophobic oscillating cylinder. Applying the slip condition causes the drag and root-mean-square lift coefficients to reduce by 46 and 75% in comparison to the no-slip case, respectively. It also augments the average Nusselt number by 55% accompanied by a 21% increase of the natural shedding frequency compared to the no-slip cylinder. Considering the reduction of force coefficients, it is shown that the application of slip over a 135° segment of the surface is an optimum case, resulting in 47% and 85% decrease of the drag and root-mean-square lift coefficients, respectively. Application of slip over the surface of the cylinder also causes the average Nusselt number to become nearly 6 times greater than the no-slip oscillating cylinder at the lock-in condition. Further analysis based on thermal performance index (TPI) proves that a high value of TPI = 6 can be reached for the superhydrophobic cylinder.

Effect of ZnO nanofluids on thermo-hydraulic characteristic of flow in a heated duct

ABSTRACT Utilizing nanofluids in place of traditional fluids is an innovative technique to boost heat exchange capability, as conventional fluids are ineffectual due to their limited thermal conductivity. In this study, nanofluids containing zinc oxide are produced at concentrations ranging from 0% to 1.5% by volume. Nanofluids are evaluated for zeta potential and particle size using a particle analyzer based on dynamic light scattering (DLS) and electrophoretic light scattering (ELS). The particle distribution curve for 0.2% concentration peaks at approximately 102 nm, but for 1.5% it moves to 185 nm, demonstrating that agglomeration increases at greater concentrations. All of the produced nanofluids are stable and exhibit zeta potentials greater than 30 mV. The stable nanofluids are characterized for viscosity and thermal conductivity as a function of concentration and temperature. The thermal conductivity of nanofluid is observed to increase with concentration and temperature, whereas the viscosity increases with concentration but decreases with temperature. A maximum increase of 12.1% in thermal conductivity and 30% increase in viscosity are found at 1.5% concentration. By passing it through a heated rectangular duct, the heat transfer characteristics of a ZnO nanofluids are determined numerically. The Nusselt number and entropy generation rate are examined at various temperatures and concentrations. Nusselt number is observed to rise with concentration with a maximum of 9.2% augmentation at 60 for 1.5% concentration whereas the rate of entropy generation decreases with concentration. In addition, the thermal performance index of the flow is found to rise with concentration from 0.956 at 0.2% concentration to 0.991 at 1.5% concentration.

Numerical simulation of solar parabolic trough collector with helical grooves using Cu nanoparticles

In this study the effects of modification with creation of grooves as well as the use of nanoparticles with the base fluid has been considered. The main objective during the investigation is to predict the effect of enhancement in thermal efficiency with variation in thermal as well as hydraulic performance of the system. The use of nanoparticles improves the thermal conductivity as well as the hydraulic performance of the PTCs. It is seen that at lower values of Pop (Pop less than 0.20); the difference between the thermal efficiency (η) of conventional parabolic trough collector (CPTC) and parabolic trough collector with internal circular cut helical grooves (HG) systems are about 11.31–13.11 % higher. While the η of HG with copper nanoparticles (HG + Cu) is the highest and lowest thermal performance index (TEI) with 60.4 % and 0.159 respectively among three PTCs. Therefore, the η can be increased either by enhancement in thermal performance or by hydraulic performance.

Thermal-hydraulic modeling of heat sink under force convection: Investigating the effect of wings on new designs

This study aims to investigate the heat transfer performance and fluid flow characteristics of different geometrical configurations of new heat sinks. The effect of wings and number of pins on the performance of the heat sinks were numerically investigated. Rigorous heat transfer models, including its associated physical parameters such as surface area were derived for each new design. The results show that adding wings to the pin fins significantly increases heat dissipation from the hot spots. However, there was 47 % heat transfer enhancement of Perforated Hollow Pin-Fin Heat Sink (PHPFHS) with wings when compared with (PHPFHS) without wings. At a velocity of 5 m/s, the corresponding pressure drop for Cone Pin-Fin Heat Sink (CPFHS) without Wings is 10 Pa and that of CPFHS with wings is about 23 Pa. The formation of vortex at the rear of the pin fins causes an increase in pressure drop. The CPFHS with wings has the maximum thermal performance index η which ranges from 1.6 to 2.4 The complex structure of the heat sinks with wings increases the flow resistance and suppresses the flow separation. A relative comparison of the results shows that vortex formation is minimal and suppressed for heat sinks without wings.

Energy, exergy, and sustainability a novel comparison of conventional gas turbine with fuel cell integrated hybrid power cycle

In this paper, six novel modified exergy relations are explored to determine the precise estimation of exergy destruction and to identify which component has the most improvement potential. For this, three power generation cycles are considered, i.e., simple gas turbine (SGT), recuperated gas turbine (RGT), are compared with a novel hybrid system (SOFC-RGT: Solid Oxide Fuel Cell-RGT), which operates with fuel flexibility as well as enhanced work-output and thermal efficiency. For energy, exergy, and sustainability studies, numerical modeling is conducted using MATLAB. At rp = 4, TIT = 1250 K, an exclusive comparison has been made between proposed configurations based on thermodynamic modeling and exergy-based sustainability index. It is found that with the inclusion of a recuperator and a fuel cell in the proposed cycles, the thermal and sustainability performance tend to increase significantly. Whereas, exergy destruction increases but has minimal impact on comparing thermal performance and sustainability index. In terms of sustainability, RGT is 30.76% more sustainable than SGT, while SOFC-GT is 63.39% more sustainable than RGT.