Thermal Diffusion Ratio Research Articles

Analytical and numerical study of thermo-solutal convection in pulsating flows between two coaxial cylinders

This research reports an analytical and numerical study of thermo-solutal convection in pulsating flows between two coaxial cylinders under a pressure gradient and subject to Dirichlet-type boundary conditions for temperature and concentration along the vertical walls of the annulus. The numerical procedure used in this work is mainly based on the solution of the momentum equations and coupled with the energy and concentration equations. The finite difference method is adopted to solve governing equations using the implicit Crank-Nicolson time marching scheme in the fluid domain and the alternating direction implicit method inside the inner cylinder. The effect of the various parameters such as the fluid-solid conductivity ratio, thermal diffusivity ratio, buoyancy ratio, Lewis number, Richardson number, aspect ratio, and radius ratio on the heat and mass transfer characteristics and the flow structure is presented and discussed. The governing equations are solved analytically after separating into a steady case and an oscillatory case, where an analytical solution for velocity profile, temperature, and concentration distributions is obtained in terms of Bessel’s functions, while the analytical solutions of temperature and concentration profiles are keeping symmetry with the increase of the radius ratio. The results show that the analytical profile can reproduce the three fields obtained numerically and thus for the whole range of parameters.

Weakly nonlinear analysis of rotating magnetoconvection with anisotropic thermal diffusivity effect

The influence of anisotropic thermal diffusive coefficient on the stability of the horizontal fluid planar layer rotating about its vertical axis and permeated by the horizontal homogeneous magnetic field is studied. The linear stability analysis is carried out using the normal mode method. The stationary cross/oblique and parallel modes are calculated for different ranges of control parameters arising in the system. The SA (Stratification Anisotropy) parameter, α (the ratio of horizontal and vertical thermal diffusivities), plays a key role in deciding the boundaries between these modes and their instability regions when there is a combination of high and low rotation with weak and strong magnetic fields. The obtained isotropic results coincide with those obtained by pioneers in the literature. The weakly nonlinear behavior of the stationary convective motion in the vicinity of primary instability threshold is studied using the two-dimensional Landau–Ginzburg (LG) equation with cubic nonlinearity. This equation derived using the multiple scale analysis is similar to the one obtained in the literature having different relaxation time, nonlinear coefficient, and coherence lengths. These coefficients are used to study the heat transfer rate. In the case of high rotation, Nusselt number gets decreased from atmospheric (α < 1) to oceanic (α > 1) SA types. The domain for secondary instability of Eckhaus is obtained using the spatiotemporal LG equation and it is observed that the Eckhaus instability region decreases with increasing α.

Effects of O2 concentration of O2/CO2 co-flow on the flame stability of non-premixed coaxial jet flame

Greenhouse gas emissions should be reduced to stop the advance of global warming. Oxy-fuel combustion is one of the methods to reduce CO2 emissions. This paper aims to study the stabilization of CO2-diluted oxy-methane non-premixed jet flames and compare this with the results of methane-air flames. The lower the co-flow velocity and the higher the oxygen concentration in the co-flow, the higher the stability. If the flame stability is strong enough to withstand flame shape changes from the over-ventilated flame to the under-ventilated flame, the flammable range without blowout increases significantly under the under-ventilated flame. Otherwise, by decreasing the liftoff flame stability, the over-ventilated flame cannot change to the under-ventilated flame and blows out near the globally stoichiometric condition. The flame stability of a CO2-diluted oxy-fuel flame can differ from that of methane-air flames due to the properties of CO2 and N2. The effective velocity proposed by Guiberti et al. shows a good collapse of the dimensionless liftoff height among the O2/CO2 co-flow, but the dimensionless liftoff height under the air co-flow is not on the same line with the O2/CO2 co-flow. This study suggests a modified dimensionless liftoff height equation considering the fuel and co-flow mixture kinematic viscosity instead of the fuel kinematic viscosity and the ratio of the thermal diffusivity of the mixture. The thermal diffusivity ratio does not affect the result of the air co-flow. Additionally, the new coefficient β and turbulent Schmidt number are suggested because these numbers are factors depending on the burner geometry. The modified effective velocity using new coefficients and the modified dimensionless liftoff height show a good collapse for not only O2/CO2 co-flows but also air co-flow. Also, the modified effective velocity shows the possibility of the critical liftoff velocity prediction.

Plasma sprayed K2Ti6O13 as thermal barrier coatings with high thermal swing for diesel piston enabled by inter-splat bonding and porosity tailoring

Thermal swing coatings with high thermal diffusivity but low thermal conductivity could increase the efficiency of diesel engines by minimizing the piston surface thermal gradient. However, the thermal diffusivity is usually positively related to the thermal conductivity and thus it is generally difficult to deposit thermal barrier coating with a low thermal conductivity but high thermal diffusivity by plasma spraying. In the present work, K2Ti6O13 with intrinsic low thermal conductivity and low melting point (1350 °C) was used as the coating material to prepare a coating with a high ratio of thermal diffusivity to thermal conductivity. Results revealed that due to the low melting point feature of K2Ti6O13 all plasma sprayed coatings have high inter-splat bonding quality which resulted in a high thermal diffusivity close to the sintered counterpart. K2Ti6O13 coatings of high porosity were plasma sprayed by optimizing powder structure, which leads to a low thermal conductivity but influences little the thermal diffusivity. It is also found that the preferential evaporation of potassium oxide from the K2Ti6O13 molten droplets leads to the formation of the TiO2 phase and generates global pores in the coating. At optimized spray conditions by using sintered porous powder, the K2Ti6O13 coating with a porosity of 21 % and single K2Ti6O13 phase reveals the lowest thermal conductivity of 0.85 W/m·K and a high diffusivity of 0.43 mm2/s. The coating exhibits the highest thermal swing of about 91 °C, having much higher performance than the conventional thermal barrier coatings used for enhancing the thermal swing effect.

Influence of variable viscosity and local thermal non-equilibrium on nanofluid flow stability in an inclined porous channel

This study delves into the influence of local thermal non-equilibrium and changing viscosity on the stability of nanofluid flow in an inclined porous channel. The flow in the porous region governs Brinkman’s equation as well as a three-field model for temperature, with each field constitute the fluid, particle, and solid-matrix phases individually. Eigenvalue problem for a perturbed state is obtained using a normal mode analysis, and the problem is afterwards solved by the utilization of the Chebyshev spectral collocation method. Impact of various local thermal non-equilibrium parameters, critical Rayleigh number, and associated wavenumber are graphically displayed. Increasing values of the modified thermal capacity ratios, modified thermal diffusivity ratios, variable viscosity parameter, and channel inclination decrease the system’s stability for the interphase heat transfer parameter, which means these parameters destabilize the flow. Flow is most unstable when the channel is vertically oriented and the variable viscosity parameter ([Formula: see text]) = 0.5.

Transport Coefficients for the Simple Reacting Spheres Kinetic Model II: Thermal Conductivity, Diffusion, Thermal-Diffusion Ratio

We investigate the transport coefficients for a dilute reactive mixture of four constituents undergoing a chemical reaction of type A+B⇌C+D\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$A+B \\rightleftharpoons C+ D$$\\end{document}, which is described by the Simple Reacting Spheres (SRS) kinetic model. The dynamics of the SRS model is very interesting and relatively simple. Both reactive and inert collisions obey to the hard spheres potential and the collisional operator incorporates a “correction” term that singles out those pre-collisional pairs of particles having enough energy to react chemically. Starting from this setting, we consider the mixture in a chemical regime for which both elastic and reactive collisions occur with comparable characteristic times and use the Chapman–Enskog method to determine the first-order approximation of the non-equilibrium solution to the SRS system. In a preceding paper (part I), the focus was on the coefficients associated to reaction rate and shear viscosity and in the present work we are interested on the coefficients associated to thermal conductivity, diffusion, and thermal-diffusion ratio. These coefficients are analysed numerically for both exothermic and endothermic reactions. The analysis allows to investigate the influence of the chemical reaction and the impact of the “correction” term proper of the SRS model on the transport coefficients.

Heat transfer in drop-laden turbulence

Heat transfer by large deformable drops in a turbulent flow is a complex and rich-in-physics system, in which drop deformation, breakage and coalescence influence the transport of heat. We study this problem by coupling direct numerical simulation (DNS) of turbulence with a phase-field method for the interface description. Simulations are run at fixed-shear Reynolds and Weber numbers. To evaluate the influence of microscopic flow properties, like momentum/thermal diffusivity, on macroscopic flow properties, like mean temperature or heat transfer rates, we consider four different values of the Prandtl number, which is the momentum to thermal diffusivity ratio: $Pr=1$ , $Pr=2$ , $Pr=4$ and $Pr=8$ . The drop volume fraction is $\varPhi \simeq 5.4\,\%$ for all cases. Drops are initially warmer than the turbulent carrier fluid and release heat at different rates depending on the value of $Pr$ , but also on their size and on their own dynamics (topology, breakage, drop–drop interaction). Computing the time behaviour of the drops and carrier fluid average temperatures, we clearly show that an increase of $Pr$ slows down the heat transfer process. We explain our results by a simplified phenomenological model: we show that the time behaviour of the drop average temperature is self-similar, and a universal behaviour can be found upon rescaling by $t/Pr^{2/3}$ . Accordingly, the heat transfer coefficient $\mathcal {H}$ (respectively its dimensionless counterpart, the Nusselt number $Nu$ ) scales as $\mathcal {H}\sim Pr^{-2/3}$ (respectively $Nu\sim Pr^{1/3}$ ) at the beginning of the simulation, and tends to $\mathcal {H}\sim Pr^{-1/2}$ (respectively $Nu\sim Pr^{1/2}$ ) at later times. These different scalings can be explained via the boundary layer theory and are consistent with previous theoretical/numerical predictions.

Role of applying PCMs on thermal behavior of innovative unit roof enclosure

As a technical approach, using Phase Change Materials (PCM) can be an effective method to prevent energy losses through building enclosures. In the present paper, different roof structures containing PCM have been examined to analyze their thermal behavior. The governing equations were developed and solved for a sample unit extracted from a typical roof. The control volume based finite element method has been applied for solving coupled equations governing heat transfer through the roof and flow of melted PCM. The effect of key parameters including thermal diffusivity of the PCM and the wall, Prandtl number (Pr), Rayleigh number (Ra) and solid wall thickness to total thickness has been examined. The main results indicate an enhancement of heat transfer through the increase of the thermal diffusivity of the PCM with respect to the building material. Increasing the thermal diffusivity ratio from 1 to 25 doubles the heat transfer rate and decreases the full melting time by 80% for high Rayleigh. Pr affects the mode of heat transfer but has little impact on PCM melting rate. Raising Ra improves heat transfer under the condition of high thermal diffusivity in the PCM. Increasing Rayleigh number from 104 to 106 doubles the heat transfer rate and reduces the melting by 67% for high thermal diffusivity ratio. Finally, increasing the size of the wall thickness does not affect the fraction of melted PCM but reduces the heat transfer rate. The heat transfer rate can be increased by up to 75% when the non-dimensional thickness of the solid layer is reduced from 0.5 to 0.005.

The Combined Effect of Coriolis Force and Double Diffusive for the Convention in a Rectangular Isotropic and Anisotropic Porous Channel

The combined effects of Coriolis force, heat, and mass diffusion for the convection in a horizontal rectangular channel filled with fluid in both isotropic and anisotropic porous channels is studied in the three-dimensional case for which the governing equations with the boundary conditions are derived with the help of the following assumptions: the fluid is incompressible; the flow is axisymmetric about the y-axis; the fluid is steady; thermal diffusion is larger than the viscous diffusion. With the help of the stream function, the resultant equations are made dimensionless, and non-dimension parameters like Rac, Rs along with anisotropic aspect ratio of permeabilities and thermal diffusivities are introduced. Later, the resulting linear partial differential equations are solved by the method of Fourier series analysis. The effect of the non-dimensional numbers plays a vital role in controlling parameters like velocity, temperature, and concentration for both isotropic and anisotropic cases. The expression for critical Rayleigh number has been established for both isotropic and anisotropic cases. Various computations are carried out in order to study the effects of velocity, temperature, concentration, and Critical Rayleigh number for different values of non-dimensional parameters. The obtained results are in good agreement with previous literary works and also have a wide application in the real world which can be seen in different industries.

Revised Enskog theory for Mie fluids: Prediction of diffusion coefficients, thermal diffusion coefficients, viscosities, and thermal conductivities.

Since the 1920s, the Enskog solutions to the Boltzmann equation have provided a route to predicting the transport properties of dilute gas mixtures. At higher densities, predictions have been limited to gases of hard spheres. In this work, we present a revised Enskog theory for multicomponent mixtures of Mie fluids, where the Barker-Henderson perturbation theory is used to calculate the radial distribution function at contact. With parameters of the Mie-potentials regressed to equilibrium properties, the theory is fully predictive for transport properties. The presented framework offers a link between the Mie potential and transport properties at elevated densities, giving accurate predictions for real fluids. For mixtures of noble gases, diffusion coefficients from experiments are reproduced within ±4%. For hydrogen, the predicted self-diffusion coefficient is within 10% of experimental data up to 200 MPa and at temperatures above 171K. Binary diffusion coefficients of the CO2/CH4 mixture from simulations are reproduced within 20% at pressures up to 14.7 MPa. Except for xenon in the vicinity of the critical point, the thermal conductivity of noble gases and their mixtures is reproduced within 10% of the experimental data. For other molecules than noble gases, the temperature dependence of the thermal conductivity is under-predicted, while the density dependence appears to be correctly predicted. Predictions of the viscosity are within ±10% of the experimental data for methane, nitrogen, and argon up to 300bar, for temperatures ranging from 233 to 523K. At pressures up to 500bar and temperatures from 200 to 800K, the predictions are within ±15% of the most accurate correlation for the viscosity of air. Comparing the theory to an extensive set of measurements of thermal diffusion ratios, we find that 49% of the model predictions are within ±20% of the reported measurements. The predicted thermal diffusion factor differs by less than 15% from the simulation results of Lennard-Jones mixtures, even at densities well exceeding the critical density.

Unified formulation of convective heat flux and mass flux vectors with thermodynamic coupling and related transfer coefficients

Based on the inherent thermodynamic relations of compressible species in binary mixtures at constant pressure, the general three-dimensional (3D) convective heat flux and mass flux vectors are formulated including the contributions of simultaneous advection, thermal diffusion and mass diffusion and their coupling effects between temperature and concentration gradients. The novel expressions for the diffusion-thermo and thermo-diffusion effects do not require the meager data of thermal diffusion ratio and are valid for both gas and liquid mixtures in laminar flows. The unified flux forms of the Maxwell's electromagnetic equation type are obtained in convective processes. It is further shown that the surface convective heat and mass transfer coefficients can be expressed in terms of the convective heat fluxes and mass fluxes away from surfaces in steady laminar flows, and that the expression of each transfer coefficient yields the identical form on both impermeable and permeable surfaces.

Role of edge-localized neoclassical tearing modes in quiescent H-mode plasmas in the DIII-D tokamak

The edge-harmonic oscillations (EHOs) in standard quiescent H-mode (QH-mode) plasmas in DIII-D are consistent with edge-localized neoclassical tearing modes (NTMs) based on nonlinear two-fluid MHD simulations. Using kinetic equilibria constrained by edge profile measurements, the MHD simulations show that the n = 1 NTM and its harmonics can be destabilized at the pedestal top of QH-mode plasma by the edge bootstrap current. The simulations further show that the unstable NTMs can saturate either at small (<2% ψN) or large (>4% ψN) island width depending on the magnitude of the edge bootstrap current, where ψN is the normalized radius in poloidal flux. The onset of the EHO also results in a prompt decrease in the pedestal width and height, consistent with simulation results for the onset of the NTM at the top of the QH-mode pedestal. This suggests that the avoidance of edge-localized modes (ELMs) in QH-mode can be attributed to the enhanced local transport induced by the NTM that is sufficient to prevent the expansion of the pedestal to an unstable width, analogous to the mechanism explored for ELM suppression by resonant magnetic perturbations. Nonlinear MHD simulations scanning the E × B frequency and the ratio of parallel and perpendicular thermal diffusivity (χǁ/χ⊥) at the pedestal top show that edge-localized NTMs are destabilized for conditions of high E × B frequency, high pedestal temperature, and low pedestal density, qualitatively consistent with experimental conditions required for observing the EHO.

HEAT AND MASS TRANSPORT IN A NANOFLUID LAYER USING A THERMAL NONEQUILIBRIUM MODEL CONFINED WITHIN A HELE-SHAW CELL UNDER THE EFFECT OF GRAVITY MODULATION

The local thermal nonequilibrium (LTNE) condition is the temperature difference between the base fluid and the nanoparticle. In the present research article, linear analysis was done to know about the onset of convection in the system, and a weakly nonlinear stability analysis was done to know about heat and mass transport in the system for both the unsteady and steady case. Here we have taken temperature to be constant and nanoparticle flux to be zero at the upper and lower boundaries of the system. The normal mode technique is used for linear analysis, and the truncated Fourier series method is used for nonlinear analysis; plot streamlines, isotherms, and isohaline are used to visualize the conduction, convection, and steady state. We found that the behavior of Hele-Shaw cell is the same in the case of LTNE and local thermal equilibrium (LTE). The effect of Hele-Shaw number, interphase heat transfer coefficient, modified thermal capacity ratio, thermal diffusivity ratio, amplitude, and frequency of modulation on the onset of convection, heat, and mass transfer are depicted graphically. We found that the effect of LTNE can be seen only for the intermediate values of the interphase heat transfer coefficient, and this region is called the LTNE region. We also discuss the result of thermal Nusselt number, streamlines, and isothermals of fluid and particle phase for steady case and plot the graphs with respect to the Hele-Shaw cell Rayleigh number. Rate of heat transfer for the particle phase is higher than the fluid phase for both the unsteady and steady state. In this research paper we find the result for both LTE and LTNE conditions with unsteady and steady cases, while in the previous study we analyzed only for the LTE condition.

THE EFFECT OF LOCAL THERMAL NON-EQUILIBRIUM AND MAGNETIC FIELD ON THE STABILITY IN A VERTICAL CHANNEL FILLED WITH NANOFLUID

In this investigation, the influence of local thermal non-equilibrium (LTNE) on the onset of convection in a channel occupied with nanofluid was examined. The flow took place in the presence of a transverse magnetic field. The Buongiorno and two-field models (each independently signifying the fluid and particle phases) were used for the nanofluid and energy equation, respectively. A normal mode analysis was applied to obtain the eigenvalue problem for the disturbed state, which was solved using the Chebyshev spectral collocation technique. The effects of the governing parameters on the Rayleigh number and corresponding wavenumber are presented graphically. It was noticed that the concentration Rayleigh number, inter-phase heat transfer parameter, and modified diffusivity ratio had a destabilizing effect, while the modified thermal capacity ratio, thermal diffusivity ratio, Lewis number, and modified particle density increment had a stabilizing effect on the system.

Numerical study on the effect of thermal diffusivity ratio in phase change heat transfer of crude-oil using lattice Boltzmann method

When the long distance crude-oil pipe-line is stopped, the crude-oil will solidify gradually with the decrease of the temperature in the pipe-line. The solid-liquid thermal diffusivity can reflect the ability of heat diffusion in the phase change heat transfer process of crude-oil stop-transport. Based on the mathematical model of oil phase transition heat transfer established by enthalpy method, the lattice Boltzmann method is used to solve the governing equations of oil phase transition heat transfer. According to the simulation results, the phase change heat transfer process of crude-oil is divided into three-stages, and the mechanism of the phase change heat transfer process of crude-oil is studied. The results show that the influence of solid-liquid thermal diffusion ratio increase gradually with time. When Fourier number ?0.043, Nusselt number and convective heat transfer intensity of mobile phase interface slightly decrease with the increase of solid-liquid thermal diffusivity ratio. The research results of this paper can provide a reference for controlling the stoppage time of pipe-line.

UNSTEADY TRIPLE-DIFFUSIVE CONVECTION EMBEDDED WITH DARCY-BRINKMAN THREE-TEMPERATURE MODEL

The theory of binary nanofluid layer heated and soluted from below under the effect of local thermal non-equilibrium has been investigated by applying the technique of superposition of basic feasible modes with one-term Galerkin residual method. The so-called Darcy-Brinkman model for the top-heavy distribution of nanoparticles has been employed. A three-temperature local thermal non-equilibrium (LTNE) model, assuming one-temperature field for the solid matrix, one for the base fluid, and one for the suspended nanosized particles, is employed, incorporating the effects of Brownian and thermophoretic diffusions. Numerical computations are carried out with the software Mathematica (version 12.0). The novelty of the problem lies in the fact that destabilizing influence of nanoparticles and solute is countered with stabilization due to the presence of Darcy-Brinkman porous medium. Further, it has been observed that the two LTNE parameters namely, Nield parameter for particles and modified solute thermal capacity ratio, have destabilizing effects which are balanced by the other two parameters, viz. Nield parameter for solute and modified thermal capacity ratio for particles. The impact of nanofluid parameters is found to destabilize this top-heavy configuration of nanoparticles. Due to the consideration of Darcy-Brinkman model, Darcy number came into existence, which postpones the onset of instability. Similar is the effect of porosity and modified thermal diffusivity ratios for the particles as well as the solute.

Local Thermal Non-Equilibrium Dominant Darcy-Rayleigh-Benard-Magneto-Marangoni Convection in a Composite Layer

The domination by Local Thermal Non-Equilibrium (LTNE) with regard to the onset of Darcy-Rayleigh-Benard-Marangoni (DRBM) convection swayed by magnetic field in a composite layer set-up is studied pertinent to incompressible fluid. The precinct above the fluid layer is presumed to be free and that below the porous layer is presumed to be rigid. Regular perturbation technique is exercised on the acquired problem to achieve the analytical solution taking adiabatic-adiabatic conditions into account at the boundaries. Effects of parameters such as solid phase thermal expansion ratio, solid phase thermal diffusivity ratio and inter-phase thermal diffusivity ratio that influences LTNE are discussed. The impact of change in measures of variables viz. fluid phase thermal expansion ratio, fluid phase thermal diffusivity ratio, porous parameter, thermal ratio, Chandrasekhar number and Marangoni number with respect to both LTNE and LTE situations are together explored and portrayed graphically. It is to be noted that for smaller values of fluid phase thermal expansion ratio and fluid phase thermal diffusivity ratio, the LTNE effects are prominent and cannot be ignored.

Repercussions of Local Thermal Non-Equilibrium in Conjunction with Uniform/Non-Uniform Thermal Gradients and Magnetic Flux on the Onset of Darcy-Rayleigh-Benard-Marangoni Convection in a Composite Layer

Repercussions of uniform/non-uniform thermal gradients such as linear, parabolic, inverted parabolic, piecewise linear gradient heated from below (PLHB), piecewise linear gradient cooled from above (PLCA) and step function (SF) thermal gradients in conjunction with magnetic flux on the onset of Darcy-Rayleigh-Benard-Marangoni (DRBMM) convection in a composite layer involving incompressible fluid and holding horizontal adiabatic boundaries, rigid beneath the porous layer and free aloft the fluid layer is performed apropos to Local Thermal Non-Equilibrium (LTNE). Regular Perturbation method is exercised to attain the analytical solution of the acquired problem. For all the six thermal gradients, (i) The strength of variables such as solid phase thermal expansion ratio, solid phase thermal diffusivity ratio and inter-phase thermal diffusivity ratio that boosts LTNE are analysed and (ii) The influence of change in measure of physical quantities viz. fluid phase thermal expansion ratio, fluid phase thermal diffusivity ratio, Chandrasekhar number and Marangoni number are studied.

Non-Uniform Temperature Gradients Impact on Rayleigh-Darcy Convection : A Composite System with Couple Stress Fluid

The impact of non-uniform temperature gradients on Rayleigh-Darcy convection in a composite system of couple stress fluid is discussed. The composite system is bounded by stress-free surfaces and adiabatically insulated, and the fluid-porous layers are coupled by employing appropriate interfacial boundary conditions. To determine the eigen value, the regular perturbation method is used. The effect of dimensionless parameters on Rayleigh-Darcy convection is analysed graphically, and it is demonstrated that the couple stress parameter and couple stress viscosity ratio stabilise the system, while the opposite effect is observed for the Darcy number and thermal diffusivity ratio.

Impact of Magnetic Field on the Onset of Double Diffusive Rayleigh-Benard Convection Governed by Local Thermal Non-Equilibrium in a Double Layered System

Onset of Double Diffusive Rayleigh-Benard-Magneto (DDRBM) convection is studied for a double layered system composed of incompressible fluid confined by adiabatic rigid peripheries under the governance of Local Thermal Non-Equilibrium (LTNE). Result of the acquired problem is obtained analytically through the mode of Regular Perturbation. Consequence of physical factors such as solid phase thermal expansion ratio, solid phase thermal diffusivity ratio and inter-phase thermal diffusivity ratio that favours LTNE are being analysed. The outcome of altering the constraints namely fluid phase thermal expansion ratio, solute Rayleigh number, Chandrasekhar number, thermal ratio, concentration ratio, fluid phase solute diffusivity ratio, solute diffusivity ratio in fluid layer and porous layer subject to LTNE set-up are paralleled with that of LTE set-up with diagrammatic representation.