Adiabatic Index Research Articles

Optimization of thermophysical properties of nanofluids using a hybrid procedure based on machine learning, multi-objective optimization, and multi-criteria decision-making

The rheological and thermal behavior of nanofluids in real-world scenarios is significantly affected by their thermophysical properties (TPPs). Therefore, optimizing TPPs can remarkably improve the performance of nanofluids. In this regard, in the present study, a hybrid strategy is proposed that combines machine learning (ML), multi-objective optimization (MOO), and multi-criteria decision-making (MCDM) to select optimal parameters for water-based multi-walled carbon nanotubes (MWCNTs)-oxide hybrid nanofluids. In the first step, four critical TPPs, including density ratio (DR), viscosity ratio (VR), specific heat capacity ratio (SHCR), and thermal conductivity ratio (TCR), are modeled using two efficient ML techniques, the group method of data handling neural network (GMDH-NN) and combinatorial (COMBI) algorithm. In the next step, the superior models are subjected to a four-objective optimization by the well-known non-dominated sorting genetic algorithm II (NSGA-II), which aims to minimize DR/VR and maximize SHCR/TCR. This study considers volume fraction (VF), oxide nanoparticle (NP) type, and system temperature as optimization variables. In the final step, two prominent MCDM techniques, TOPSIS and VIKOR, were used to identify the desirable optimal points from the Pareto fronts generated by the MOO algorithm. ML results reveal the COMBI algorithm's superior reliability in accurately modeling various TPPs. The pattern of Pareto fronts for all oxide-NPs indicated that over one-third of the optimal points have a VF > 1.5 %. On the other hand, the distribution of optimal points across different temperature ranges varied significantly depending on the type of oxide-NPs. For Al2O3-based nanofluid, around 90 % of the optimal points were within 40–50 °C. Conversely, for nanofluids containing CeO2 NPs, only approximately 24 % of the optimal points were found within the same temperature range. Considering diverse scenarios for weighting TPPs in the MCDM process implied that combining CeO2/ZnO oxide-NPs with MWCNTs in water-based nanofluids is highly effective across various real-world applications.

Bioconvection flow of NEPCM and oxytactic microorganisms within a porous circular cylinder containing a circular cylinder fin using an artificial neural network in conjunction with the ISPH method

This article investigates the bioconvection flow within a porous circular cylinder filled with oxytactic microorganisms and incorporating nano-encapsulated phase change materials (NEPCMs). The circular cylinder, equipped with T-fins, is situated within the cylinder’s domain. The governing equations are solved using the ISPH method based on a time-fractional derivative. An ISPH simulation, coupled with an artificial neural networks (ANN) model, is employed to predict the values of the average Nusselt number ( Nu ¯ ). Utilizing bioconvection flow within a porous circular cylinder containing oxytactic microorganisms and integrating NEPCMs presents opportunities for progress in thermal management, environmental engineering, energy storage, and materials science. During the conducted simulations, we have investigated the impacts of Darcy, Lewis, Peclet, Rayleigh, and bioconvection Rayleigh numbers on a range of parameters, encompassing isotherms, heat capacity ratio, concentration profiles of oxygen and microorganisms, velocity field, and Nu ¯ . The results obtained highlight the significant influence of changes in the inner cylinder’s radius and fin length on regulating the intensity of bioconvection flow and improving heat transfer within a cavity. Additionally, the fusion temperature causes a shift in the heat capacity ratio toward the heat sources located within the cavity. The velocity field decreases by 97.39 % as the Darcy number decreases from 10 − 2 to 10 − 5 due to the challenges posed by porous media. Increasing the length of the T-fin enhances the cooling area, causing the isotherms to contract and altering the heat capacity ratio. In comparison to the target values, the ANN model demonstrates accurate prediction of Nu ¯ , bolstering confidence in its predictions.

Singularity‐Free Charged Compact Star Model Under F(Q)$F(Q)$‐Gravity Regime

AbstractIn this paper, the possibility of existing a novel class of compact charged spheres based on a charged perfect fluid within the realm of gravity theory is explored. The authors started by proposing physically meaningful explicit formulas for the potential, denoted , and the electric field to find a close‐form solution. More precisely, the change of the dependent variable approach by exploiting the transformation is applied. Successively, the field equations analytically are solved and generate the most general solution, which leads us to examine various significant aspects of the stellar system. These aspects comprise the regularity of gravitational potentials, energy density and pressure, electric charge, the mass‐radius relationship, subluminal sound velocities in the radial direction, and the adiabatic index for charged compact stars. For a more in‐depth system study, mass measurements using contour diagrams are carried out. This mainly involves varying the variable parameters and to distinguish their effect on the mass distribution within the stellar structure. What is more, the electric charge controls the stability of the stellar system is shown, which yields that a stable system can possess a maximum charge of order . The results strongly argue that charged stars could conceivably exist in nature and that such a deviation from traditional theories may be seen in future astrophysical observations.

Continuous and discontinuous compressible flows in a converging–diverging channel solved by physics-informed neural networks without exogenous data

Physics-informed neural networks (PINNs) are employed to solve the classical compressible flow problem in a converging–diverging nozzle. This problem represents a typical example described by the Euler equations, a thorough understanding of which serves as a guide for solving more general compressible flows. Given a geometry of the channel, analytical solutions for the steady states do indeed exist, and they depend on the ratio between the back pressure of the outlet and the stagnation pressure of the inlet. Moreover, in the diverging region, the solution may branch into subsonic flow, supersonic flow, or a mixture of both with a discontinuous transition where a normal shock occurs. Classical numerical schemes with shock fitting and capturing methods have been developed to solve this type of problem effectively, whereas the original PINNs are unable to predict the flows correctly. We make a first attempt to exploit the power of PINNs to solve this problem directly by adjusting the weights of different components of the loss function to acquire physical solutions and in the meantime, avoid trivial solutions. With a universal setting yet no exogenous data, we are able to solve this problem accurately; that is, for different given pressure ratios, PINNs provide different branches of solutions at both steady and unsteady states, some of which are discontinuous in nature. For an inverse problem such as unknown specific-heat ratio, it works effectively as well.

Viable and Stable Compact Stellar Structures in f(Q,T)$f(\mathcal {Q},\mathcal {T})$ Theory

AbstractThe main objective of this paper is to investigate the impact of gravity on the geometry of anisotropic compact stellar objects, where is non‐metricity and is the trace of the energy‐momentum tensor. In this perspective, the physically viable non‐singular solutions to examine the configuration of static spherically symmetric structures is used. A specific model of this theory to examine various physical quantities in the interior of the proposed compact stars (CSs) is considered. These quantities include fluid parameters, anisotropy, energy constraints, equation of state parameters, mass, compactness, and redshift. The Tolman–Oppenheimer–Volkoff equation is used to examine the equilibrium state of stellar models, while the stability of the proposed CSs is investigated through sound speed and adiabatic index methods. It is found that the proposed CSs are viable and stable in the context of this theory.

Possible existence of Bose–Einstein condensate compact stars

In this paper, we have model a compact star model composed of Bose–Einstein Condensate (BEC) matter that satisfy a polytropic equation of state (EoS) with γ=2 and a specific density profile. Then we tested the model through various physical criteria like non-singular pressure and density, energy conditions, causality condition etc. Further, we have checked the stability through Bondi criterion, hydrostatic equilibrium and static stability criterion. The stiffness of the EoS, stability, adiabatic index and Mmax depends upon a single parameter k. As k increases, the central Γ decreases near 4/3 and the compactness increases closer to 4/9 while the mass that can hold when increasing central density due to radial perturbation decreases, implies that the system will undergo gravitational collapse sooner if k increases. We have also found that this new category of compact star also follows that constraints provided by GW 170817 event. Hence, this work put forward the possibility of different category of compact star composed of BEC matters that can mimic neutron stars.

Modal Analysis of Combustion Chamber Acoustic Resonance to Reduce High-Frequency Combustion Noise in Pre-Chamber Jet Ignition Combustion Engines

<div>The notable increase in combustion noise in the 7–10 kHz band has become an issue in the development of pre-chamber jet ignition combustion gasoline engines that aim for enhanced thermal efficiency. Combustion noise in such a high-frequency band is often an issue in diesel engine development and is known to be due to resonance in the combustion chamber. However, there are few cases of it becoming a serious issue in gasoline engines, and effective countermeasures have not been established. The authors therefore decided to elucidate the mechanism of high-frequency combustion noise generation specific to this engine, and to investigate effective countermeasures. As the first step, in order to analyze the combustion chamber resonance modes of this engine in detail, calculation analysis using a finite element model and experimental modal analysis using an acoustic excitation speaker were conducted. As a result, it was found that there are two combustion chamber resonance modes in the 7–10 kHz band, both of which affect the high-frequency oscillation of the in-cylinder pressure. Both resonant modes have mode shapes that form a single nodal plane in the diametrical direction including the central axis of the cylinder, but the orientations of those nodal planes differ by 90 degrees. In addition, the two resonance frequencies are influenced by not only the bore diameter, temperature, and heat capacity ratio, but also the spatial shape of the combustion chamber. Therefore, when the piston descends and the spatial shape of the combustion chamber changes, the resonance frequencies change as well.</div>

Numerical investigations of spike velocity of microjetting from shock-loaded aluminum and tin

Microjetting is induced by the interaction between incident shock wave and material free surface. Moreover, spike velocity is one of the most important parameters to quantify the microjetting processes. The spike velocity over a wide range of shock and surface conditions for aluminum and tin is achieved via systematical Eulerian peridynamic simulations. The four popular spike velocity models are assessed according to the simulation data. The results indicate that the model proposed by Dimonte et al. based on Richtmyer–Meshkov instability (RMI) mechanism is in best agreement with the simulated spike velocities. The further analysis highlights that the dependence of adiabatic index on material states should be taken into account because it can impact the RMI flows. Then an improved spike velocity model is proposed and the comparative investigations indicate that it exhibits an overall better prediction compared to the original velocity model.

Dynamically Charged Spheres and their Stability in Einstein‐Gauss‐Bonnet Gravity

AbstractElectrically charged anisotropic fluid spheres with vanishing expansion scalar condition under the influence of a newly established gravitational scheme are investigated in this study, i.e., Einstein‐Gauss‐Bonnet (EGB) gravity. Glavan and Lin introduced this framework, in which they rescaled the coupling factor using and derived the gravitational field equations. The work of Herrera et al. is extended to explore the dynamical instability of charged spherically symmetric matter distribution in the context of EGB gravity. In this respect, dynamical equations, conservation equations, and junction conditions for charged sphere are computed. To study the evolution of considered system in the Newtonian and post‐Newtonian regimes against an expansion‐free background, several substantial restrictions are imposed employing a perturbation approach. This study showed that the adiabatic index () has no effect on the instability ranges in the aforementioned approximations. It is analyzed that the determination of these ranges solely attributed to the anisotropy of fluid surface pressures, radial profile, EGB factors, and charged intensity parameters along with the radial distribution of energy density.

EMHD stagnation point flow of dusty hybrid nanofluid over a permeable stretching sheet: Radiative solar applications

The primary objective of this paper is to investigate the impact of dusty hybrid nanofluid electromagnetohydrodynamics (EMHD) on the stagnation point flow in the presence of solar radiation. Base fluids contain ethylene glycol, water, silver, titanium alloy, and suspended dust particles. Nonlinear differential equations with two or more independent variables define fluid flow phenomena. The governing equations can be solved by the MATLAB solver by employing a suitable numerical method, like R–K fourth order via shooting method. The isothermals for various parametric values have been explained. Because it has the potential to greatly advance the disciplines of industrial and thermal engineering, this proposed model is useful. When compared to using a single base fluid, the combination of two additional base fluid qualities provides noteworthy results. Because we were able to acquire a lower freezing point than water and better heat conductivity than pure ethylene glycol when we employed the combination of the two base fluids. Glycol water is used in car coolant and solar heating systems for a variety of purposes. Impact of embedded physical quantities like electric field parameter, ratio of specific heat, porosity parameter, stagnation parameter, radiation parameter, heat source parameter, and fluid particle interaction parameter for both velocity and temperature are illustrated graphically. Dust particles have a notable impact on various sectors, including the food and pharmaceutical industries. Specifically, they are special importance in applications such as wastewater treatment, solids drying, and the presence of plastic-coated metal items. In the present work, we observe that the stagnation parameter enhances the momentum boundary layer (MBL) thickness because the dusty fluid dominates the dusty hybrid nanofluid while incorporating the Ag + Ti alloy/EG + Water. The radiation becomes more efficient at evenly spreading heat, potentially resulting in a more uniform temperature distribution. Silver and titanium alloy particles may affect the thermal conductivity of dusty hybrid nanofluid when compared to the dusty fluid. The porosity parameter enhances the fluid flow and penetration by the porous medium, which lowers friction between the skin and the surface and reduces resistance.

Magnetohydrodynamic free convection of nano-encapsulated phase change materials between two square cylinders: Mapping the thermal behavior using neural networks

The study focused on investigating the convective heat transfer of nano-encapsulated phase change suspensions in the presence of a non-uniform magnetic field within an annuli space between two square cylinders. The principal equations for the fluid flow and phase change heat transfer were formulated as partial differential equations and then represented into dimensionless format. The finite element method was used to solve these equations and simulate the free convection heat transfer. The effect of various factors, including Hartmann, Rayleigh, Eckert and Stefan numbers, geometry aspect ratio, nanoparticles’ concentration, and fusion temperature, on the heat transfer rate was examined. A neural network was also introduced and trained to establish the connection between the control parameters (inputs) and the heat transfer rate (output). The outcomes were presented in the form of the modified Nusselt number, along with isotherms, heat capacity ratio (phase change) contours, and streamlines. The results demonstrated that the neural network could accurately predict the heat transfer rate and provide a comprehensive map of heat transfer with respect to the control parameters. Nano-Encapsulated Phase Change Materials (NEPCMs) can be considered as a new type of nanofluids, in which the nanoparticle consists of a core and a shell. The core part is made of a Phase Change Material (PCM) which can undergo solid-liquid phase change at a certain fusion temperature, and absorb/release a significant amount of energy due to latent heat of the phase change.

Quantum effects on dynamic structure factors in dense magnetized plasmas

We extend the classical magnetohydrodynamics formalism to include nonlocal quantum behavior via the phenomenological Bohm potential. We then solve the quantum magnetohydrodynamics equations to obtain a new analytical form of the dynamic structure factor (DSF), a fundamental quantity linking theory and experiments. Our results show that the three-peak structure—one central Rayleigh peak and two Brillouin peaks—of the DSF arising from quantum hydrodynamic fluctuations becomes (in general) a five-peak structure—one central Rayleigh peak and two pairs of peaks associated with fast and slow magnetosonic waves. The Bohm contribution influences the positions and characteristics (height, width, and intensity) of the peaks by introducing three significant modifications: (i) an increase in effective thermal pressure, (ii) a reduction in the adiabatic index, and (iii) an enhancement of effective thermal diffusivity. The multiple DSF peaks enable concurrent measurements of diverse plasma properties, transport coefficients, and thermodynamic parameters in magnetized dense plasmas. The potential for experimental validation of our theory looms large, particularly through future experiments conducted at state-of-the-art laser facilities. Published by the American Physical Society 2024

Evaluation of weak discontinuity in rotating medium with magnetic field, characteristic shock and weak discontinuity interaction

Abstract In this article we investigated the characteristic shock and weak discontinuity wave in a rotating medium of perfect gas in the case of one-dimensional (1-D) adiabatic motion under an axial magnetic field governed by the system of PDEs (partial differential equations). We have obtained some classes of analytical solutions of the system of PDEs that demonstrates the time-space dependency. With change in the values of rotational parameter, adiabatic index and the ratio of initial magnetic pressure to dynamic pressure, effect on the acceleration wave’s amplitude and jump in the flow variables across the characteristic shock is analyzed in detail. We have obtained an expression for the jump in shock acceleration, the amplitudes of transmitted and reflected waves caused by the incident wave on the characteristic shock after the interaction of a weak discontinuity. It is investigated that the jump function across the characteristic shock decay effect, and goes to 0 as time t → ∞, whereas a weak discontinuity wave may culminate into a shock wave, depending on the initial amplitude value. It is also found that the shock formation time reduces due to the consideration of magnetic field or rotating medium.

Oscillating shocks in the transonic viscous, variable Γ accretion flows around black holes

ABSTRACT We investigate the time evolution of the transonic-viscous accretion flow around a non-rotating black hole. The input parameters used for the simulation are obtained from semi-analytical solutions. This code is based on the total variation diminishing routine and correctly handles the angular momentum transport due to viscosity. The thermodynamic properties of the flow are described by a variable adiabatic index equation of state. We regenerate the inviscid and viscous steady-state solutions, including shocks, using the simulation code and compare them with the semi-analytical solutions. The angular momentum piles up across a shock due to shock-jump conditions and viscous transport of angular momentum. This will push the shock-front outward and can result in shock oscillation or a complete destabilization of shock. We study how shocks behave in the presence of viscosity. As the viscosity parameter (α) crosses a critical value, the previously steady shock becomes time-dependent, eventually leading to oscillations. The value of this critical viscosity depends on the injection angular momentum (λou) and the specific energy (ϵ). We estimated the posteriori bremsstrahlung and synchrotron cooling, and the net radiative output also oscillates with the frequency of the shock. We also study the variation of frequency, amplitude, and mean position of oscillation with α. Considering a black hole with a mass of 10 M⊙, we observed that the power spectrum exhibits a prominent peak at the fundamental frequency of a few to about tens of Hz, accompanied by multiple harmonics. This characteristic is frequently observed in numerous accreting black hole candidates.

Theory and simulation of shock waves freely propagating through monoatomic non-Boltzmann gas

The effect of non-Boltzmann energy distributions on the free propagation of shock waves through a monoatomic gas is investigated via theory and simulation. First, the non-Boltzmann heat capacity ratio γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}, as a key property for describing shock waves, is derived from first principles via microcanonical integration. Second, atomistic molecular dynamics simulations resembling a shock tube setup are used to test the theory. The presented theory provides heat capacity ratios ranging from the well-known γ=5/3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma = 5/3$$\\end{document} for Boltzmann energy-distributed gas to γ→1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma \\rightarrow 1$$\\end{document} for delta energy-distributed gas. The molecular dynamics simulations of Boltzmann and non-Boltzmann driven gases suggest that the shock wave propagates about 9% slower through the non-Boltzmann driven gas, while the contact wave appears to be about 4% faster if it trails non-Boltzmann driven gas. The observed slowdown of the shock wave through applying a non-Boltzmann energy distribution was found to be consistent with the classical shock wave equations when applying the non-Boltzmann heat capacity ratio. These fundamental findings provide insights into the behavior of non-Boltzmann gases and might help to improve the understanding of gas dynamical phenomena.Graphical abstract

Efficiency and power enhancement strategies for methane direct injection argon power cycle engines

Argon Power Cycle (APC) is a novel concept for high efficiency and zero carbon emissions, which replaces the air by an argon-oxygen mixture. Previous studies have experimentally demonstrated that APC has a great efficiency enhancement potential for methane-fueled engines. However, the port methane injection tends to cause knock and limits thermal efficiency gains. In addition, few researches have focused on the power of APC methane-fueled engines. In this study, fundamental experiments are first conducted in a spark ignition methane direct injection engine with compression ratio = 9.6. Strategies such as lean combustion, dilution combustion (increasing argon mole ratio in argon-oxygen mixture), and boosting intake pressure are adopted. Results indicate that lean combustion has a more significant effect in efficiency enhancement under APC compared with air cycle due to the high specific heat ratio of argon. The combination of dilution combustion and boosting intake pressure is a feasible approach to further improve both efficiencies and powers. When argon mole ratio = 85 %, intake pressure = 0.12 MPa, and excess oxygen ratio = 1.37, the highest net indicated thermal efficiency reaches 59.0 % and the indicated mean effective pressure increases a factor of 1.61 than that at argon mole ratio = 79 % and intake pressure = 0.09 MPa. In this case, the ratio of gross indicated thermal efficiency to theoretical thermal conversion efficiency is 90.5 %. Based on thermodynamic calculation, when the ratio of gross indicated thermal efficiency to theoretical thermal conversion efficiency is assumed to be 90 %, a high net indicated thermal efficiency of 65 % is predicted to be obtained at compression ratio = 14.

Acousto- and acousto-optic effects in liquid crystals: An overview

An overview of the following three aspects of the acoustical and related optical behavior of liquid crystals, namely i) ultrasonic studies, ii) acousto-optical effects, and iii) surface wave induced optical effects have been discussed. The temperature dependent ultrasound velocity has been used for the evaluation of the adiabatic compressibility (kS) and the acoustic impedance (Z). A correlation between thermodynamic functions and thermo-elastic properties facilitated the evaluation of the specific heat at constant volume (CV), the ratio of specific heats (g) and the isothermal compressibility (kT) across liquid crystal-isotropic phase transition. Acousto-optical effect in liquid crystals has been described in terms of molecular reorientation related to flows and turbulences due to acoustic vibration and radiation pressure in the medium. One important aspect of the acousto-optical effects is the surface wave induced optical effects. The change in transparency of a normal layer of liquid crystal under crossed polarizers are discussed which is interpreted as a consequence of the rotation of the optic axis. In addition, the acoustic emission occurring from homeotropically-aligned liquid crystals irradiated by surface acoustic waves are also discussed.

Compact stellar model with vanishing complexity under Vaidya–Tikekar background geometry

We make use of the condition of vanishing complexity, based on the current definition proposed by Herrera (Phys Rev D 97:044010, 2018), to find exact interior solutions to the Einstein equations for describing compact stellar objects. In the framework of general relativity, the complexity factor is an outcome of the orthogonal splitting of the Riemann tensor from which structure scalars are obtained. By using the Vaidya–Tikekar (V–T) metric ansatz (J Astrophys Astron 3:325, 1982) for the spacetime of a static spherically symmetric matter distribution, we model superdense, relativistic stars. The interior spacetime is matched to the exterior Schwarzschild solution across the boundary of the star where the radial pressure vanishes. The physical viability of the model has been tested following the current data corresponding to the pulsar 4U1820-30\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ 4U 1820-30 $$\\end{document}. The stability of the model fulfilled the given criteria, namely the Tolman–Oppenheimer–Volkoff equation, the adiabatic index and the causality conditions.

Modeling of Stellar solutions in Einstein–Gauss–Bonnet gravity

This article addresses an entirely novel class of stable compact stellar configurations under Einstein–Gauss–Bonnet gravity. To analyze the compact objects, we have taken into account spherically symmetric metric and adopted the Krori–Barua geometries. For this theoretical framework to accommodate neutron stars, the incorporation of the Gauss–Bonnet term is very important. Numerous physical characteristics of compact models, involving material variable, and its stability, have been thoroughly examined for Gauss–Bonnet coupled parameter. We also examine the stability of these stellar models while taking into consideration a variety of parameter values. Additionally, we delve into an exploration of the hydrostatic equilibrium of the compact system, achieved by utilizing a modified form of Tolman–Oppenheimer–Volkoff equation. Furthermore, we have assessed the stability of the solution by examining the square of the speed of sound velocity, the adiabatic index, and its critical values. In addition to this, we demonstrate a correlation inside mass and radius to derive the values of compactness factor and surface redshift of our obtained model. This comprehensive approach allows us to ascertain that the obtained stellar model attach to the fundamental physical requisites essential for a viable and physically meaningful stellar object.

Viable and stable compact stars in f(Q)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f({\\mathcal {Q}})$$\\end{document} theory

In this paper, we study the viability and stability of anisotropic compact stars in the context of f(Q)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f({\\mathcal {Q}})$$\\end{document} theory, where Q\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathcal {Q}}$$\\end{document} is non-metricity scalar. We use Finch–Skea solutions to investigate the physical properties of compact stars. To determine the values of unknown constants, we match internal spacetime with the exterior region at the boundary surface. Furthermore, we study the various physical quantities, including effective matter variables, energy conditions and equation of state parameters inside the considered compact stars. The equilibrium and stability states of the proposed compact stars are examined through the Tolman–Oppenheimer–Volkoff equation, causality condition, Herrera cracking approach and adiabatic index, respectively. It is found that viable and stable compact stars exist in f(Q)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f({\\mathcal {Q}})$$\\end{document} theory as all the necessary conditions are satisfied.