Volumetric Entropy Generation Rate Research Articles

Entropy generation analysis of electroosmotic mixed convection flow in vertical microannulus with asymmetric heat fluxes

Flow formations and heat transfer of electroosmotic flow have significant applications in area of heat exchanger and recently for chemical separation at microlevel. Therefore in this article, exact solutions for entropy generation rate of electroosmotic mixed convection flow in a vertical microannulus subject to asymmetric heat fluxes are presented. Closed form solutions in terms of Bessel's functions are obtained for electric potential, fluid velocity, temperature, skin-friction, Nusselt number and entropy generation after transforming the governing equations into their corresponding dimensionless forms. The obtained solutions are graphically represented using MATLAB software in order to ascertain the role of various pertinent parameters entering flow formation and heat transfer. Results obtained showed that entropy generation rises with increase in radius ratio and electroosmotic force but decreases with increase in slip and buoyancy parameters. Also, irreversibility due to fluid friction or applied electric field is sufficient to dominant the overall entropy generation rate in the presence of strong buoyancy force. On application point of view, fluid velocity, temperature distributions, skin-friction, volumetric flow rate, Nusselt number and entropy generation rate can be optimized by careful selection of governing parameters.

Entropy Generation and Regression Analysis of Magnetohydrodynamic Stagnation Point Flow of a Casson Fluid with Radiative and Dissipative Heat Transfer and Hall Effects

The phenomenon of heat transfer is prevalent in industries and has an extensive range of applications. However, mostly the discussion of heat transfer problems is limited to the study of the first law of thermodynamics, which deals with energy conservation. It is just restricted to the quantity of energy, not to its quality; i.e., there is no difference between the work (high‐grade energy) and the heat (low‐grade energy). A measurement of the degree of randomness of energy in a system is known as entropy. It is unavailable for doing useful work because work takes place only from ordered molecular motion. Even though many boundary layer models exist in the literature to investigate the flow and heat transfer of various fluids along a stretching surface, they have not yet been used at their maximum ability. The main motive of the current research is to discuss entropy generation or its minimization during heat transfer. This work presents an entropy generation analysis for the transient three‐dimensional stagnation point flow of a hydromagnetic Casson fluid flowing over a stretching surface in the existence of Hall current, viscous dissipation, and nonlinear radiation. The physical configuration of the present work is described in terms of partial differential equations (PDEs) of nonlinear nature. Furthermore, these PDEs are converted into ordinary differential equations by using some relevant similarity transformations. An efficient numerical method named as the spectral quasilinearization method (SQLM) is used to solve this model. The expression of the Bejan number and volumetric entropy generation rate is also computed. A parametric analysis, including the essential physical parameters, is performed to examine the influences of distinct flow parameters on the velocity profile, temperature profile, Bejan number, entropy generation number, and the coefficients of skin friction and the Nusselt number. In order to further insight into the emerging physical quantities of engineering interest, multiple quadratic regression models are used to estimate the coefficients of skin friction and heat transfer.

Entropy Generation Rate for Stationary Ballistic-Diffusive Heat Conduction in a Rectangular Flake

Thermodynamic irreversibility in low dimensional flake is considered and entropy generation rate in two-dimensional thin film is examined, Equation of phonon radiative transfer is solved for two-dimensional and rectangular diamond flake. Volumetric and total entropy generation rate are evaluated incorporating the formulation of thermal radiation heat transfer. The influence of flake aspect ratio (width to height) on the entropy generation rate is explored while keeping the Diamond flake area constant for all aspect ratios considered. The findings reveal that the entropy generation rate increases with increasing aspect ratio for fixed boundary conditions.

Volumetric entropy generation rate associated with tip clearance flow in linear cascade

The tip clearance flow structure and its corresponding entropy generation rate of a linear cascade with 1.85mm radial tip clearance operating under three different incidence angle are investigated. The incidence angle influences the tip leakage vortex position as well as the size of the tip leakage vortex. Larger incidence angle results in larger tip leakage vortex and pushes the tip leakage vortex further away from the suction side. The entropy generation rate related to the tip clearance flow structure is calculated and it is confirmed that tip clearance flow is the main major source of aerodynamic loss in linear cascade. Larger incidence angle leading to higher entropy generation rate. Results also show that it’s not the core region of tip leakage vortex but the edge vortex and shear layer of the tip clearance flow which has the highest entropy generation rate. When operating under an incidence angle of 4°, there exist an extra high entropy generation rate region in main flow. It is found that the compression and expansion of fluid due to the existence of tip clearance vortex was the main reason for this extra high entropy generation.

Effects of MHD and porosity on entropy generation in two incompressible Newtonian fluids over a thin needle in a parallel free stream

This article is devoted to studying Magnetohydrodynamic (MHD)'s combined effect and porosity on the entropy generation in two incompressible Newtonian fluids over a thin needle moving in a parallel stream. Two Newtonian fluids (air and water) are taken into consideration in this study. The viscous dissipation term is involved in the energy equation. The assumption is that the free stream velocity is in the direction of the positive x-axis—(axial direction). The thin needle moves in the same or opposite direction of free stream velocity. The reduced similar governing equations are solved numerically with the help of shooting and the fourth-order Runge–Kutta method. The expressions for dimensionless volumetric entropy generation rate and Bejan number are obtained through using similarity transformations. The effects of the magnetic parameter, porosity parameter, Eckert number, Bejan number, irreversibility parameter, Nusselt number, and skin friction are discussed graphically in detail for and taken as Newtonian fluids. The results are compared with published work and are found in excellent agreement.

A brief comparative study of gamma alumina–water and gamma alumina–EG nanofluids flow near a solid sphere

Here we deliberate a new class of nano-materials with two different types of nanoparticles which immensely magnify the thermo-physical properties and thermal transport proficiency of nano-liquid. Prandtl number exhibits a primitive role in regulating thermal or momentum boundary layer regions. Therefore, keeping such comprehensive spectrum in view we contemplated MHD natural convection flow of steady, 2D, incompressible nanoliquids of gamma alumina–water and gamma alumina–EG towards a solid heated sphere. Viscosity is supposed to be temperature dependent. Governing non-linear PDEs are formed. To renovate the PDEs into system of ODEs a felicitous transformation has been employed. The converted non-linear equations are executed numerically via BVP4C. The numerical conclusions derived for velocity and thermal distributions are perceived through graphs for two different cases, effective Prandtl number and without effective Prandtl number. A careful consideration of preceding dissertation discloses that, the significance of an empirical based Prandtl number model on the boundary layer flow of gamma alumina–water and gamma alumina–EG on a solid sphere with temperature dependent viscosity is not examined yet. A comparison reveals that gamma alumina–EG offers better thermal transfer enhancement than gamma alumina–water. Entropy generation number Ns is the ratio of local volumetric entropy generation rate to the characteristic entropy generation rate. Entropy generation analysis is also perceived and the behavior of Gr number relative to entropy generation number Ns is also presented. A parametric analysis of the substantial parameters such as magnetic field parameter M, nanoparticle volume fraction parameter ω temperature parameter θr and Gr number are ascertained and representative set of numerical examination for thermal and velocity distributions are depicted graphically to present the influential features of the solutions.

A numerical study on mechanisms of energy dissipation in a pump as turbine (PAT) using entropy generation theory

Abstract The utilization of pumps in reverse function is one of the economically beneficial methods for off-grid power generation in micro-hydropower capacities. The traditional method of hydraulic loss calculation in turbomachinery based on pressure drop calculations is unable to determine the exact location of losses. In this paper, the irreversible energy losses within the PAT has been studied for the first time using entropy generation theory and the second law of thermodynamics point of view. In order to conduct numerical simulation, the 3-dimensional incompressible steady-state flow within the PAT is simulated by solving the Reynolds averaged Navier-Stokes (RANS) equations. The shear stress transport (SST) turbulence model is considered for turbulence modeling. The quantity of direct (viscous) and turbulent entropy generation rate is calculated in different PAT components in 9 different flow rates in the range of 0.7QBEP to 1.3QBEP. The numerical results show that the turbulent term is the main factor of entropy production within the PAT (86.89%–90.98%), and thus, turbulent entropy generation is the dominant mechanism for hydraulic losses. More than 50% of the energy dissipation occurs within the PAT runner. Most of the losses within the runner take place at the blade leading edge, blade trailing edge and flow separation regions of the blade suction and pressure sides. The volumetric entropy generation rate analysis demonstrates that the draft tube has the most potential to generate irreversible losses among all the components (47.37%). Flow field analysis reveals that the blade inlet shock, flow deviation at the blade outlet, flow separation, backflow and vortices in flow passages are categorized as the main reasons for entropy production and irreversible hydraulic losses within the PAT components. The advantages of the entropy generation method including the determination of the exact location and quantity of energy dissipation within the PAT are indicated in this investigation.

Numerical study of the effects of adverse pressure gradient parameter, turning angle and curvature ratio on turbulent flow in 3D turning curved rectangular diffusers using entropy generation analysis

Turning diffuser is a type of diffuser with certain angle of turn used as adapter or ejector in flow line for energy recovery. It is also employed in HVAC systems, wind tunnels, piping systems, gas turbine cycles and aircraft engine. Although significant works have been done on diffusers in the literature but not much focus has been given to the 3D turning diffuser. In this study, the effects of curvature ratio, adverse pressure gradient parameter and tuning angle on entropy generation rate due to viscous dissipation, turbulent dissipation, volumetric entropy generation rate and efficiency are investigated in the curved rectangular diffuser under turbulent flow regime. The tuning angles, curvature ratios and adverse pressure gradient parameters are considered $$ \theta = 60^{^\circ } ,80^{^\circ } ,90^{^\circ } ,\frac{\delta }{R} = 0.0113, 0.0161, 0.023 $$ and $$ \beta = 0.56, 0.62, 0.86 $$ , respectively. The analysis on entropy generation using Bejan’s entropy generation equation for curved rectangular diffuser with different turning angles, curvature ratios and adverse pressure gradient parameters has not been addressed before and is introduced in this study for the first time. Results show that in order to reach the maximum efficiency with minimum entropy generation for curved rectangular diffuser design in air-conditioning systems, the highest turning angle, the lowest adverse pressure gradient parameter and curvature ratio should be selected. In addition, the efficiency increases with increasing turning angle, and decreasing the adverse pressure gradient parameter and curvature ratio. Finally, it is concluded that for all different turning angles, curvature ratios and adverse pressure gradient parameters, the entropy generation due to turbulence dissipations is more than the entropy generation due to viscous dissipations.

Investigation on the thermohydraulic performance of high temperature superconducting (HTS) cables with heat loads using Entropy Generation Minimization (EGM) approach

High temperature superconducting (HTS) cables have revolutionized the way of power transmission in terms of carrying larger currents with lower volume of the conductor. However, such cables experience AC losses which are dissipated as heat. Hence, it is inevitable that these cables be cooled below the critical temperature of the superconductor constituting the HTS cable. In general, LN2 is circulated through the former (corrugated pipe) to retain the superconductivity of HTS tapes. The work consumed for pumping LN2 through long length HTS cables is significantly larger. Hence, it is necessary that the optimization of the pumping power with enhanced heat transfer is achieved. During the process of forced cooling of HTS cables, velocity and thermal gradients which are responsible for entropy generation is unavoidable. Hence, in the present work, an investigation on thermohydraulic performance in HTS cables with various heat loads is performed. Further, the volumetric rate of entropy generation is calculated and an optimum mass flow rate is identified at which minimum entropy generation rate is observed. The thermohydraulic performance and total entropy generation rate for internally cooled HTS cables are computationally investigated using the time averaged Reynolds Averaged Navier-Stokes (RANS) equations implemented in commercial software ANSYS®. This implementation involves Finite Volume Method (FVM) of discretization with κ−ε turbulence equations as closure to the RANS governing equations. Temperature dependent thermophysical properties are considered for predicting the thermohydraulic behavior of LN2 in HTS cable. The analysis is carried out at heat loads ranging from 1-3 W/m with flow rates of 11-20 L/min at an operating temperature of 77 K and pressure of 2.7 bar. The dimensionless numbers such as Bejan number, entropy generation number and performance evaluation are studied to evaluate the optimum flow rate corresponding to lower pumping power and higher cooling capacity at various heat loads. Further, the results obtained from computational simulations are validated with the experimental results available in the literature. Furthermore, the results of volumetric entropy generation rate (EGR) are calculated to optimize the thermohydraulic performance in HTS cables using entropy generation minimization (EGM) approach.

Entropy generation in MHD Maxwell nanofluid flow with variable thermal conductivity, thermal radiation, slip conditions, and heat source

It is important to study heat transfer processes due to fluid flow in the context of entropy because the efficiency of such systems depends on reduction in entropy generation. Moreover, there is a need to develop mechanisms to control entropy generation in thermal systems. In this work, we study volumetric entropy generation rate in electrically conducting Maxwell nanofluid over a penetrable stretching sheet with variable thermal conductivity, velocity slip conditions, thermal radiation, and internal heat source effect. The governing equations of flow, heat transfer, and entropy generation have been abridged under the suppositions of boundary layer approximations and low Reynolds numbers. Solutions to the governing system of partial differential equations are carried out by transforming them into the system of ordinary differential equations using suitable similarity transformations. The resultant system is then solved numerically using a shooting technique along with the fourth order RK method. Numerical computations are carried out for water based Cu-water and Al2O3-water nanofluids. Corporeal topographies of velocity, temperature, entropy generation, Bejan number, skin friction coefficient, and Nusselt number are presented. The impact of important physical parameters are discussed through graphs and tables.

Entropy Generation Minimization (EGM) in High Temperature Superconducting (HTS) cables for optimization of thermohydraulic performance

High Temperature Superconducting (HTS) cables have potential merits of large current carrying capacity and compactness with reduced transmission losses and Right-of-Way (RoW) compared to conventional transmission power cables. However, internal forced convective cooling is necessary to cool HTS cables using cryogenic coolant such as liquid nitrogen (LN2) to retain the superconductivity for efficient power transmission. Due to forced convective cooling, inevitable pressure drop occurs in these cables and result in development of temperature and velocity gradients. Further, the accounted temperature and velocity gradients in HTS cables lead to volumetric entropy generation which causes reduction in thermohydraulic performance.The present work focuses at investigating the volumetric entropy generation rate in HTS cable. Further, Entropy Generation Minimization (EGM) technique is used as an optimization tool to estimate the minimum volumetric entropy generation rate to optimize thermohydraulic performance in HTS cables. Furthermore, pumping power and cooling capacity at minimum entropy generation rate are calculated. Computational Fluid Dynamics (CFD) is used to analyze the pressure drop and heat transfer rate for different flow rates to estimate the friction factor, pumping power and cooling capacity with flow of LN2 in corrugated former in HTS cable. A 3D computational geometry is developed using commercial software ANSYS®. Relevant boundary conditions are imposed on the computational geometry to reflect the practical operating conditions of HTS cable. Finite Volume Method (FVM) of discretization is used to solve the governing equations in order to obtain pressure drop and heat transfer rate in HTS cables. The simulated results are validated with the results available in literature. From the analysis, it is identified that at a heat load of 2.1 W/m and at an inlet temperature of 77 K, optimum cooling capacity and pumping power with minimum entropy generation rate are possible at a flow rate of 14 L/min.

Modeling heat transfer of nanofluid flow in microchannels with electrokinetic and slippery effects using Buongiorno’s model

PurposeThis paper aims to study the heat transfer of nanofluid flow driven by the move of channel walls in a microchannel under the effects of the electrical double layer and slippery properties of channel walls. The distributions of velocity, temperature and nanoparticle volumetric concentration are analyzed under different slip-length. Also, the variation rates of flow velocity, temperature, concentration of nanoparticle, the pressure constant, the local volumetric entropy generation rate and the total cross-sectional entropy generation are analyzed.Design/methodology/approachA recently developed model is chosen which is robust and reasonable from the point of view of physics, as it does not impose nonphysical boundary conditions, for instance, the zero electrical potential in the middle plane of the channel or the artificial pressure constant. The governing equations of flow motion, energy, electrical double layer and stream potential are derived with slip boundary condition presented. The model is non-dimensionalized and solved by using the homotopy analysis method.FindingsSlip-length has significant influences on the velocity, temperature and nanoparticle volumetric concentration of the nanofluid. It also has strong effects on the pressure constant. With the increase of the slip-length, the pressure constant of the nanofluid in the horizontal microchannel decreases. Both the local volumetric entropy generation rate and total cross-sectional entropy generation rate are significantly affected by both the slip-length of the lower wall and the thermal diffusion. The local volumetric entropy generation rate at the upper wall is always higher than that around the lower wall. Also, the larger the slip-length is, the lower the total cross-sectional entropy generation rate is when the thermal diffusion is moderate.Originality/valueThe findings in this work on the heat transfer and flow phenomena of the nanofluid in microchannel are expected to make a contribution to guide the design of micro-electro-mechanical systems.

Entropy generation analysis of combustion process adopting blended propane/hydrogen fuels in micro-combustor

In order to further optimize the working performance of micro combustor, the distribution of volumetric entropy generation rate and exergy efficiency of premixed propane/hydrogen combustion and channel height of 2 to 3 mm in micro-combustor are studied numerically. The entropy generation rates induced by chemical reaction, thermal conduction and mass diffusion are calculated by taking the second law of thermodynamics into account. It is found that the main component of entropy generation is converted from chemical reaction to thermal conduction with hydrogen addition ratio increasing. At the same time, the entropy generation rates due to chemical reaction and mass diffusion are reduced as the hydrogen addition ratio rise. Since the channel height of the micro combustor increases, the region of entropy generation shrinks towards the inlet. Although the value of entropy generation increases obviously under the same condition, the contribution of entropy generation caused by chemical reaction is weakened, while the part of thermal conduction is enhanced. And this phenomenon is more obvious with hydrogen addition ratio rising. The exergy efficiency of combustor at 2 mm channel height increases by 8% with different hydrogen addition ratios compared with 3 mm, which is considered as more suitable for blended combustion.

Thermodynamic Analysis of Entropy Generation Minimization in Thermally Dissipating Flow Over a Thin Needle Moving in a Parallel Free Stream of Two Newtonian Fluids.

This article is devoted to study sustainability of entropy generation in an incompressible thermal flow of Newtonian fluids over a thin needle that is moving in a parallel stream. Two types of Newtonian fluids (water and air) are considered in this work. The energy dissipation term is included in the energy equation. Here, it is presumed that u∞ (the free stream velocity) is in the positive axial direction (x-axis) and the motion of the thin needle is in the opposite or similar direction as the free stream velocity. The reduced self-similar governing equations are solved numerically with the aid of the shooting technique with the fourth-order-Runge-Kutta method. Using similarity transformations, it is possible to obtain the expression for dimensionless form of the volumetric entropy generation rate and the Bejan number. The effects of Prandtl number, Eckert number and dimensionless temperature parameter are discussed graphically in details for water and air taken as Newtonian fluids.

Role of Heating Location on the Performance of a Natural Convection Driven Melting Process Inside a Square-Shaped Thermal Energy Storage System

Abstract In this work, numerical experiments were performed to compare the heat transfer and thermodynamic performance of melting process inside the square-shaped thermal energy storage system with three different heating configurations: an isothermal heating from left side-wall or bottom-wall or top-wall and with three adiabatic walls. The hot wall is maintained at a temperature higher than the melting temperature of the phase change material (PCM), while all other walls are perfectly insulated. The transient numerical simulations were performed for melting Gallium (a low Prandtl number Pr = 0.0216, low Stefan number, Ste = 0.014, PCM with high latent heat to density ratio) at moderate Rayleigh number (Ra ≊ 105). The transient numerical simulations consist of solving coupled continuity, momentum, and energy equation in the unstructured formulation using the PISO algorithm. In this work, the fixed grid, a source-based enthalpy-porosity approach has been adopted. The heat transfer performance of the melting process was analyzed by studying the time evolution of global fluid fraction, Nusselt number at the hot wall, and volume-averaged normalized flow-kinetic-energy. The thermodynamic performance was analyzed by calculating the local volumetric entropy generation rates and absolute entropy generation considering both irreversibilities due to the finite temperature gradient and viscous dissipation. The bottom-heating configuration yielded the maximum Nusselt number but has a slightly higher total change in entropy generation compared to other heating configurations.

Entropy generation for flow of Sisko fluid due to rotating disk

This investigation deals with entropy generation optimization and nonlinear dissipative flow of Sisko fluid due to a rotating disk. Joule heating effect is considered. Mathematical model is obtained for the present flow problem. Nonlinear systems are solved for convergent series solutions. Analysis of various flow variables on Bejan number, volumetric entropy generation rate, temperature and velocity are discussed. Present analysis depicts that irreversibility rate (entropy generation rate) and Bejan number are enhanced for radiation parameter, whereas reverse behavior is noticed for Brinkman number and material parameter. The velocity and temperature fields are increasing for larger material parameter and temperature ratio parameter. The obtained results are helpful in understanding the irreversibility (entropy generation) for flow of non-Newtonian fluids. Comparative study is made for temperature, velocity, Bejan number and entropy generation by considering shear thickening and thinning fluids. Finally, a comparison is given with the previous available results.

Optimization of entropy generation and dissipative nonlinear radiative Von Karman's swirling flow with Soret and Dufour effects

A computational investigation has been accomplished on nonlinear radiative flow between two impermeable stretchable rotating disks. Thermo-diffusion and diffusion-thermo effects are also implemented. Furthermore nonlinear radiative heat flux, heat source/sink, dissipation and chemical reaction are considered. Thermodynamics second law is used for the investigation of entropy generation and Bejan number. Total entropy generation is inspected for various flow variables. Von Karman similarity transformations are utilized to develop coupled nonlinear ordinary differential systems and then tackled by semi computational/analytical technique namely homotopy technique. Particular consideration is given to the convergence procedure. The impacts of different flow variables like magnetic interaction, porosity, thermal diffusion, Prandtl number, diffusion thermo, radiative flux, heat source/sink, Schmidt number and chemical reaction variables on fluid velocity, concentration, temperature, volumetric entropy generation rate and Bejan number are discussed and analyzed. Velocity, temperature and concentration gradients at the disk surface are calculated numerically and discussed through the tables. Velocity reduces for both Hartman number and porosity parameter. Hartman number and radiation parameter enhances the entropy generation and Bejan number. Final conclusions of present flow analysis have been presented through concluding remarks.

A Computational Study of Swirl Number Effects on Entropy Generation in Gas Turbine Combustors

ABSTRACTIn this paper, local and global entropy generation features are studied numerically in two research flames and a real combustor problem. The research flames are the well-known Burner Engineering Research Laboratory and Sandia flame D experimental flame databases and the real combustor is a gas-turbine can-type combustor. The main focus is on investigating the effect of the swirl number, in the range 0.0–2.4, on entropy generation characteristics due to different phenomena, including viscous, mass transfer, heat transfer, heat-mass coupling, reaction, and specifically radiation. For this purpose, the surface and volumetric local entropy generation rates are formulated based on the first-order spherical harmonics model known as “P1,” a frequently used model in combustion applications. It is observed that heat transfer and reactions are dominant causes of entropy generation with the leading contribution of reaction at lower swirl numbers and heat transfer at higher swirl values. The radiation entropy generation is slightly affected by the swirl number and is of prime importance only in near stoichiometric conditions. Moreover, it is indicated how this local entropy generation analysis can be used to discover the weaknesses in the design of a real combustor.

Irreversibility analysis in unsteady flow over a vertical plate with arbitrary wall shear stress and ramped wall temperature

Abstract The present paper aims to report irreversibility analysis in unsteady flow of viscous fluid over a vertical flat plate with ramped wall temperature and arbitrary wall shear stress in the presence of thermal radiation. The equations which governing the problem are solved by the method of Laplace transform. The expression for Bejan number and volumetric entropy generation rate are calculated. The effects of different embedded parameters on the Bejan number and the entropy generation number are elaborated by graphs. It is noted that entropy production in thermal system can be minimized by decreasing thermal radiation. It is also observed that heat transfer increases the entropy of the system.

Exergetic performance comparison of air and hydrogen gas flowing through the annular curved duct

The main objective of this study is to parametrically compare the exergetic performance of air and hydrogen gas flow through the curved annular duct. For this purpose, it is assumed that, i) air and hydrogen are considered to be ideal gas, ii) the flow of these gases is steady state and laminar fully developed, ii) these gases have constant physical properties, iii) the channel inner and outer walls are exposed to constant wall boundary condition. Moreover, the following important parameters are taken into consideration: i) aspect ratio (four different values which are 5.50, 3.80, 2.90 and 2.36), ii) environment temperature (ranging from −30 to 30 with 10 °C intervals), iii) Dean number (varying between 24 and 208), and iv) operating pressure (=1 atm). Considering these parameters, exergy destruction and exergy efficiencies are calculated for each aspect ratio. Consequently, exergetic efficiency rises with the increase of Dean number, inner wall temperature, aspect ratio and the decrease of dead state temperature. Also, it is noticed that the gas specie highly affects the volumetric entropy generation rate, exergy destruction rate and exergy efficiency.