Heat Transfer Nusselt Number Research Articles

Assessment of heat transfer characteristics of a corrugated heat exchanger based on various corrugation parameters using artificial neural network approach

The complexity of the fluid flow process involved makes it difficult to estimate the characteristics of corrugated tubes. Heat exchangers are often designed to be more efficient by using numerical techniques. Recently, machine learning algorithms have become a viable method for assessing the behaviors of flow and heat transfer in corrugated tubes. Based on a set of data, machine learning algorithms can better estimate how efficient a heat exchanger is. In the present study, an artificial neural network is conducted to figure out the Nusselt number, friction factor, and performance evaluation criteria for heat transfer in straight corrugated tubes based on flow rate and corrugation parameters. The Reynolds number varies between 480 and 6100, spanning various flow regimes in the corrugated tubes, while the corrugation pitch and corrugation depth change between 6 mm and 18 mm and 0.6 and 1.0 mm, respectively. After totaling 220 data points, the network structure with a multilayer perceptron structure is trained. The Levenberg-Marquardt algorithm is performed for training with 17 neurons in the hidden layer. The established neural network structure forecasts Nusselt number, friction factor, and performance evaluation criteria parameters with deviation rates of 0.11 %, −0.63 %, and 0.17 %, respectively. The neural network exhibits higher performance when compared to related correlations from the literature. This study is a novel one in open sources due to using artificial neural networks to estimate the flow and thermal behaviors in corrugated tubes operating at low flow rates. The current recommended approach may be regarded as a beneficial tool particularly for thermal systems as it aids designers in enhancing the system efficiency with accurate estimations.

An efficient numerical scheme for solving the melting transportation of energy with time dependent Carreau nanofluid

The current work is categorized into the following formatBackground: Heat transfer controlling through therapy and blood flow has clinical importance in different levels of the human body. Biological faculties utilize blood in which iron oxide nanoparticles are incorporated for contrast agents and in the biomedical fields as they possess key and intrinsic characteristics, like low toxicity, capability of blood carrying nanoparticles, surface engineering and colloidal stability. This paper has a unique approach for analysis of blood flow containing nanoparticles with mathematical model of Carreau nanofluid. Furthermore, heat transport analysis has been provided by using the melting heat conditions and free convection.Carreau nanofluid for blood flow gives a set of partial differential equations (PDEs), which are handled by using the Keller Box scheme to obtain the numerical performances of the results. The obtained results are compared with Bvp4c, which is MATLAB built in program and found smooth agreement. The graphical plots and statistical tables have been provided for various dimensionless parameters to get the numerical simulations of the problem against velocity, temperature, and heat transfer Nusselt number. From the obtained results, the velocity and temperature of the fluid diminishes by the virtue of an amplification in unsteady parameter A. A positive variation in melting parameter M in the case of Prandtl number Pr and unsteady parameter A magnifies the heat transfer Nusselt number. This article shows the novelty in the sense that the effect of Tiwari and Das model accompanied with melting heat transfer phenomenon in the case of unsteady Carreau fluid has not investigated before in the available literature related to the Carreau fluid.

Heat transfer characteristics of the innovative spray-type packed bed thermal energy storage: An experimental study

The shift to clean energy and the promotion of renewable energy sources are the dominant trends in the sustainable development of global energy employment. Thermal energy storage (TES) technology can help reduce the mismatch between thermal energy supply and demand by smoothing out peak demand periods. The spray-type packed bed thermal energy storage is an innovative heat storage technology that reduces the use of liquid heat transfer fluid (HTF) by introducing a spray device. However, the mechanism of flow and heat transfer inside the spray-type packed bed thermal energy storage is not yet clear. Therefore, in this study, a 10 kW/10 kWh spray-type packed bed TES test rig was established using aluminum spheres as storage media and thermal oil as HTF, and the heat transfer performance was studied experimentally. The results indicate that higher charging temperatures and flow rates lead to a higher liquid-to-particle heat transfer coefficient. An empirical correlation for heat transfer in spray-type packed bed TES was developed. With substantial reduction in HTF usage, the heat transfer Nusselt number of spray-type packed bed can basically approach that of a fully-filled packed bed.

Experimental investigation on the impact of fin structure factors on the finned-Trombe wall thermal performance

By increasing surface area, fins can enhance the heat transfer and improve the Trombe wall thermal performance. However, there is still a lack of detailed experimental research on the impact of fin structure factors on the thermal performance of finned-Trombe wall (F-TW). This experiment establishes a platform under laboratory conditions to investigate the impact of fin height and spacing on the F-TW thermal performance. Electric heating is used to simulate the solar radiation. The results indicate that in areas with relatively low solar radiation intensity, the F-TW is more cost-effective for improving F-TW thermal performance. The F-TW thermal parameters including air temperature rise, mass flow rate, thermal efficiency and overall natural convective heat transfer coefficient are enlarged as the fin height increases and fin spacing decreases, while the heat loss coefficient of glass cover is opposite. The fin spacing has a more significant influence on the F-TW thermal performance and natural convective heat transfer in the channel than the fin height does. The maximum thermal efficiency of 63.75% is obtained at heat flux of 860W/m2, relative fin height of 0.75 and relative fin spacing of 0.06. Finally, for the engineering design and performance assessment of F-TW, the experimental correlation is provided to calculate the average natural convective heat transfer Nusselt number in the channel.

Quadratic regression analysis for nonlinear heat source/sink and mathematical Fourier heat law influences on Reiner-Philippoff hybrid nanofluid flow applying Galerkin finite element method

BackgroundScientists across the world have tried to explore the effect of non-Newtonian fluids moving over a symmetric stretchable sheet with the presence of diverse influences revealed in this study due to its tremendous applications in various engineering and industrialized sectors like aerodynamics extrusion of plastic surfaces, condensation procedure of metal symmetric plate in a refrigeration immersion, and extrusion of a polymeric surface from a dye.Proposed modelReiner-Philippoff fluids flowing related to a symmetric stretch surface with the inclusion of effects like Forchheimer velocity, thermal radiative, and Cattaneo Christov heat fluxing are considered in the momentum and temperature equation. Novel tetra hybrid nanoparticles are considered to check the thermo physical behaviour of the proposed model. MethodologyThe showed PDEs are transformed into ODEs with the utilization of symmetric and self-similarity variables and further attempted numerically with the assistance of the Galerkin finite element methodology (G-FEM). The obtained findings are scrutinized in the form of figures and tables.FindingsFrom obtained outcomes, it is perceived that the heat transfer Nusselt magnifies extra in the instance of tetra hybrid nanofluids (THNFs) in disparity to tri and di hybrid nanoparticles. Darcy Forcheeimer effect Fr diminishes the fluid velocity and the temperature outline amplifies owed to amplification in thermal radiative variable Rd. The insertion of nanoparticles supports in the stabilizating of a nanofluid's flowand provides the symmetric of thestructure. Error in heat transfer Nusselt number diminishes by the virtue of magnification in Rd and the heat deliverance phenomenon magnifies as a consequence of enlargement in the thermal relaxation constraint.Practical application of the proposed modelDue to its particle use in manufacturing and engineering for shells that expand and contract, like stretchable (shrinkable) packaging, bundle wrapping, hot roll, sheet material extrusion, wire roll, glass fiber manufacturing, metallic packags, and aluminum bottles manufacturing, parabolic tough surface collectors, cooling of thermal reactors, polymer production, etc., the examination of two-dimensional flowing over an extending shallow has attracted attention. The proposed model outcomes are utilized in order the enhance heat transfer of the various liquids by utilizing tetra hybrid nanoparticles and effects like nonlinear based thermal radiation, Cattaneo-Christov heat flux and heat source/sink phenomenon.NoveltyThe effort is novel in its sagacity that no nanofluid model has been developed yet to examine the effect of tetra hybrid nanoparticles on liquid moving over any sort of surface.

On the energy transport and heat transfer efficiency in radiatively heated particle-laden Rayleigh–Bénard convection

We investigate the energy transport and heat transfer efficiency in turbulent Rayleigh–Bénard (RB) convection laden with radiatively heated inertial particles. Direct numerical simulations combined with the Lagrangian point-particle mode were carried out in the range of density ratio $854.7\le \rho _p/\rho _0 \le 8547$ and radiation intensity $1\le \phi /\phi _{solar}\le 100$ for both two-dimensional (2-D) and three-dimensional (3-D) simulations. The Rayleigh number ranges from $2\times 10^6$ to $10^8$ for 2-D cases, and is $10^7$ for 3-D cases for $Pr=0.71$ . It is found that particles with small density ratio that encounter strong radiation significantly alter the flow momentum transport and fluid heat transfer, so the fluid temperature of bulk is remarkably heated. We then derived the theoretical relation of the Nusselt number for interphase heat transfer in the heated particle-laden RB convection, which reveals that the heat transfer difference between the top and bottom plates stems from the interphase heat transfer. We further found that both the interphase heat transfer and the interphase thermal energy transport exhibit universal properties. They are both increased linearly with the reciprocal of the normalized density ratio. Additionally, both the interphase heat transfer and the interphase thermal energy transport increase linearly with the increase of radiation intensity. The growth rates exhibit specific scaling relations versus Rayleigh number and density ratio. Two different regimes distinguished by the critical density ratio, i.e. the exothermic particle regime and the endothermic particle regime, are observed. We further derived the power-law relation of the critical density ratios versus Rayleigh number and radiation intensity, i.e. $\rho _p/\rho _c \sim (\phi /\phi _{solar})^{1/2}\,Ra^{1/3}$ , which is in remarkable agreement with the 3-D simulations.

The measurement of friction factors and heat transfer Nusselt numbers for the flow of air and CO2 through micro tubes

The measurement of friction factors and heat transfer Nusselt numbers for the flow of air and CO2 through micro tubes

Energy integral equation for premixed flame-wall interaction in turbulent boundary layers and its application to turbulent burning velocity and wall flux evaluations

An integral form of the energy conservation equation has been derived from the first principle for low Mach number conditions for statistically steady premixed flame-wall interaction within turbulent boundary layers. The validity of this equation has been demonstrated based on three-dimensional Direct Numerical Simulation data of statistically stationary oblique quenching of a turbulent premixed V-shaped flame in a channel flow configuration as a result of its interaction with an inert isothermal wall. It has been found that the wall heat flux and the integral of chemical heat release in the wall normal direction within the turbulent thermal boundary layer are the major contributors in the energy integral equation, and their difference is accounted for by the advection contribution. The magnitudes of the wall heat flux increase, and integral of heat release rate across the thermal boundary layer decrease with increasing distance from the leading edge of the boundary layer as a result of flame quenching. The integral form of the energy conservation equation has been utilised to demonstrate that the Nusselt number (or Stanton number) for wall heat transfer is intrinsically related to the turbulent burning velocity in the case of flame-wall interaction within turbulent boundary layers. A Flame Surface Density based reaction rate closure, modified to account for the near-wall behaviour, has been utilised to estimate the mean Nusselt number in the case of flame-wall interaction within turbulent boundary layers, which revealed that the modelling limitations of the mean reaction rate closure may give rise to inaccuracies in the estimation of the mean Nusselt number. By contrast, the measurements of mean velocity, temperature, and wall heat flux can be utilised to estimate the turbulent burning velocity within the turbulent boundary layer using the newly derived energy integral equation.

Investigation of convective heat transfer from a high temperature prolate spheroid to moving fluid

Most of the currently used fluid-solid heat transfer models assume that solid particles are perfect spheres. Heat transfer between non-spherical particles and flowing fluids acquires great importance in many engineering appliances. A numerical study is performed on airflow past a stationary confined prolate spheroid under the forced convective heat transfer regime, and the influence of non-sphericity of the particle on their heating rate is examined. The prolate spheroid is assumed to be maintained at a constant wall temperature. The effect of Reynolds number (Re) and Aspect Ratio (AR) on convective heat transfer rate and Nusselt number was investigated by solving steady-state Navier-Stokes and energy equations. The influence of the flow in terms of Reynolds number and the prolate spheroid aspect ratio was investigated. The spheroid’s surface temperature (Ts) was varied between 294 K and 1500 K. The simulations show that the mean Nusselt number has a positive dependence on Ts, AR, and Re. A new correlation was developed to predict the mean Nusselt number for a wide range of temperature differences. The new correlation consolidates the influence of aspect ratio, surface temperature, and Reynolds number, in contrast to the existing correlations that assume merely isothermal conditions to calculate the mean Nusselt number for spheroid particles.

Flow and Heat Transfer Mechanisms in a Rotating Compressor Cavity Under Centrifugal Buoyancy-Driven Convection

Abstract This paper presents a systematic study of flow and heat transfer mechanisms in a compressor disk cavity with an axial throughflow under centrifugal buoyancy-driven convection, comparing with previously published experimental data. Wall-modeled large-eddy simulations (WMLES) are conducted for six operating conditions, covering a range of rotational Reynolds number (3.2×105−2.2×106), buoyancy parameter (0.11–0.26), and Rossby number (0.4–0.8). Numerical accuracy and computational efficiency of the simulations are considered. Wall heat transfer predictions are compared with measured data with a good level of agreement. A constant rothalpy core occurs at high Eckert number, appearing to reduce the driving buoyancy force. The flow in the cavity is turbulent with unsteady laminar Ekman layers observed on both disks except in the bore flow affected region on the downstream disk cob. The shroud heat transfer Nusselt number–Rayleigh number scaling agrees with that of natural convection under gravity for high Rayleigh numbers. Disk heat transfer is dominated by conduction across unsteady Ekman layers, except on the downstream disk cob. The disk bore heat transfer is close to a pipe flow forced convection correlation. The unsteady flow structure is investigated showing strong unsteadiness in the cavity that extends into the axial throughflow.

Thermodynamic and hydraulic design characteristics of the fin tube heat exchanger

Heat exchangers are crucial devices that are used to exchange heat between two different fluids: one that is hot and one that is cold. Amongst them, finned tube heat exchangers play a vital role in today’s thermal industry. Due to the increased surface area of the tubes' outer surface (or fins) when utilizing finned tube heat exchangers, the heat transfer rate may be improved as a consequence of the increased surface area of the fins. It is often referred to as a compact heat exchanger in order to highlight the comparatively large heat transfer surface area to volume ratio of the exchanger. They have many vital applications in the field of refrigeration, air conditioning, IC engines, and power plants. The fin and tube heat exchanger has been analyzed for three different cases in the present study: preheater, condenser, and evaporator. The Engineering Equation Solver (EES) software has been used to analyze the heat exchanger for the various thermal, hydrodynamic, and design parameters. Results have been plotted by comparing the various thermal parameters such as overall and inside heat transfer coefficient, Nusselt number, and rate of heat transfer with respect to Reynolds number. Similarly, the hydrodynamic parameters such as Colburn factor, friction factor, and the design parameters such as the number of fins and fin spacing.

Thermo-hydraulic performance evaluation of heat exchanger tube with vortex generator inserts

This work is undertaken as a scientific experiment to test a new design of a turbulent generator. The current research experiments the influence of novel vortex generator inserts on heat transfers within a tube under a uniform heat flux. A Cu tube with a 45 mm inner diameter and 1350 mm length is used along with a solid disc injector (swirl generator) that comprises ten crescent holes with equal circumferential distribution angles around the disk canter. Subsequently, a swirl flow is generated by deviating the stream flow 45? causing it to spin in the direction of the axial flow. Flow directors are on 45? angles toward the axial direction for each of the crescent holes. This study is an example of flow degradation. Reynolds numbers range from 6000 to 13500. Therefore, fluid-flow is treated as a turbulent system. All experiments done with air are regarded as a power fluid and Prandtl number is fixed at about 0.71. Thermo-hydraulic performance of heat exchanger is analyzed. The average heat transfer Nusselt number is calculated and discussed. The experiment found out that Nusselt number increases with an increase in Reynolds number as well as the number of swirl generators. At four vortex generators, the maximum augmentation in heat transfer is around 4.3 times greater than the plain tube and friction factor is about 1.28 with 5 vortex generators insets. The results indicate a promising heat exchanger enhancement in the local petroleum industries.

Studies on Enhanced Brake Disc Cooling using Wheel Rim with Axial Ventilators

The purpose of this study is to improve the cooling of brake disc by modifying the wheel rim by fitting it with an axial ventilator. The orientation angle of these blades in axial ventilator is varied between 0 and 10. The numerical investigation is carried out using commercial CFD code ANSYS Fluent. The pressure difference induced in 5 model is maximum leading to a better air flow through the wheel rim resulting with enhanced cooling of the brake disc. The 5 model reduced the brake disc temperature from 450C to 207.84C which is nearly 54%. The surface heat transfer coefficient and Nusselt number of 5 model is found to be maximum. The resulting improvement in heat dissipation enhances the performance and hence the lifetime of the brake disc. Therefore, the wheel rim with axial ventilator 5 model is found to the suitable configuration so as to achieve enhanced convective cooling of brake disc.

Pore-scale numerical simulation of convection heat transfer in high porosity open-cell metal foam under rotating conditions

High porosity open-cell metal foam can be used in rotating machinery to improve its performances. The interstitial heat transfer coefficient is a key parameter to describe heat transfer in porous media under local thermal non-equilibrium conditions. A pore-scale numerical simulation is performed to obtain the interstitial heat transfer coefficient between air and high porosity open-cell metal foam under rotating conditions in this study. To this end, the convective heat transfer in a radially rotating channel filled with Weaire-Phelan foam cell is investigated numerically. The interstitial heat transfer coefficients are calculated at different Reynolds numbers, Rotation numbers, foam porosities and locations. And the correlation for porous-fluid interstitial heat transfer Nusselt number is established. The results show that the increasing of Reynolds and Rotation number will gradually increase the interstitial heat transfer Nusselt number. The location also has a positive effect on the interstitial heat transfer coefficient. However, the interstitial heat transfer Nusselt number gradually decreases with the increase of porosity. The established correlation can predict the interstitial heat transfer Nusselt number with a deviation within 10% at the studied ranges of the corresponding parameters. It can also be applied to the cases for larger location, larger channel size and larger Rotation number.

Ionanofluids natural convection heat transfer and entropy generation in a rectangular cavity: Viscosity influence

Ionic liquids suspensions with nanoparticles are a new class of heat transfer fluids and this study aim is to outline and discuss the behavior of a new ionanofluid in a real life configuration. If it shortly describes the considered ionic liquid, its main drawback is the high viscosity, thus limiting its applicability in natural convection and turbulent flow applications. In this regard, this research is focused on the study of several suspensions based on a mixture between water and [C2mim][CH3SO3] and alumina nanoparticles behavior in natural convection. The study is considering different high aspect ratio cavities up to 4 and the Rayleigh number varies from 103 to 105. Nusselt number and Bejan number for heat transfer and entropy generation are evaluated. As a main conclusion, it may affirm that heat transfer decreases while the entropy generation increases with the addition of nanoparticles. Finally, even more studies are mandatory, it is recommended to use these new fluids in forced convection instead of natural convection.

Effect of new punched vortex generators in a rectangular channel on heat transfer using Taguchi method

ABSTRACT In this study, the effects of New Punched Rectangular Vortex Generators (NPRVGs) and Punched Rectangular Vortex Generators (PRVGs) inside a rectangular channel on heat transfer augmentation, Nusselt number, and friction factor were experimentally investigated. Temperature contours and average Nusselt numbers analyzed heat transfer characteristics resulting from the use of vortex generators. Furthermore, this study investigated the optimum values of the design parameters within the system of vortex generators by using the Taguchi method, and the orthogonal experimental plan was made for L16 (43x21). Reynolds numbers (5181, 10363, 20328, 25510), winglet arrangement, winglet attack angles (15°, 30°, 45°, 75°) and a distance of punched winglet from the channel bottom (b) to constant winglet height (e = 25 mm) (b/e = 0.04, 0.12, 0.2 and 0.36) were determined the working parameters in the experiments. Measurements are carried out for a rectangular channel with aspect ratio AR = 2, winglet transverse pitch (S) to longitudinal winglet height (e) ratio of S/e = 0.67 and a winglet height (e) to channel height (H = 25 mm) ratio of e/H = 1. Heat transfer rates of NPRVGs and PRVGs were compared to the obtained results for a smooth channel. The heat transfer performance is improved considerably by the NPRVGs. The maximum thermal performance factor increased from 0.99 to 1.89 owing to the combination of the vortex generator and the newly punched hole.

Effect of multibanded magnetic field on convective heat transport in linearly heated porous systems filled with hybrid nanofluid

The paper attempts to enhance the control of convective transport phenomena in magnetothermal devices applying a technique of multibanded magnetic field. For this demonstration, a typical cavity-like thermal system is considered involving linear heating, porous substance, hybrid nanofluid, and magnetic field. Four identical bands of magnetic fields are applied horizontally with uniform inactive zones between the bands. The transport equations of the coupled multiphysics evolving from the thermal buoyancy (due to linear heating at one sidewall and isothermal cooling at the opposite sidewall), filled porous medium, spatially intermittently active magnetic fields, and the engineered working fluid of Cu–Al2O3/water hybrid nanofluid are solved by an indigenously developed computing code. The study is conducted using the pertinent dimensionless parameters for the following ranges: Darcy–Rayleigh number (Ram = 1–104), Darcy number (Da = 10−5 − 10−1), Hartmann number (Ha = 0–70), and concentration of hybrid nanoparticles ϕ (= 0–2%). The convective phenomena are analyzed using the heatlines (for heat transport), streamlines (flow pattern), isotherms (static temperature), and the average Nusselt number (for heat transfer). The outcomes of this technique of multibanded magnetic field are rigorously compared with other established application methods of magnetic fields. It establishes different local behaviors along with an improved heat transfer. Heatline visualization reveals the definite portraits of heat flow paths depending upon parametric values. Furthermore, the presence of linear heating is in particular treated to explore the insight of linear heating (that featuring multiple heating and cooling zones along with the linear heater), utilizing the local Nusselt number and heatlines. One of the important advantages of this new technique is it is more energy-efficient particularly for the square or shallow cavity. The multibanded magnetic field shows a promising technique for the control of convective transport phenomena involving coupled multiphysics used during sophisticated applications (such as materials processing, biomedical applications, etc.).

Forced Convection Heat Transfer from a Cross Yawed Tube with Back Splitter Plate.(Dept.M)

An experimental investigation has been presented to study the forced convection heat transfer from a cross yawed circular tube with back splitter plate. The course of the experimental work covers Reynolds number range from 9500 to 54700, the wake splitter length varied from b = 0 to 1.5d° and the yaw angle of tube changes from 0° to 30° with respect to the cross slow orientation. The obtained results are compared with the available data in the literature. The heat transfer from the yawed tube with splitter plate is fitted as a correlation between the Nusselt, Reynolds and Prandtl numbers. This correlation indicates that the Nusselt number is a significant function of Reynolds number, yaw angle and splitter plate length. It is also seen that the effect of the yaw angle on the convective heat transfer from the tube is less than the effect of the splitter plate length, and the yawed tube with back splitter plate of length b=0.75d° and θ=30° has higher results than the other cases. A dimensionless correlation is obtained to calculate the convective heat transfer Nusselt number as a function of yaw angle, splitter plate length, Reynolds number and Prandtl number.

Scale analysis for water jet impingement over a horizontal flat plate under film boiling configuration

A scale analysis has been performed to investigate the film boiling heat transfer associated with cooling of a horizontal flat plate through water jet impinging. The forced convection film boiling of water is treated by classifying a wide spectrum of subcooling regime by two extreme situations of low and high subcooling dominated by mass evaporation and sensible heating respectively. A simple expression of heat ratio is derived for executing the classification. The ratio is derived by considering the heat and mass transport phenomena and vaporization effect. The radiation heat effect is considered, while obtaining the scale of wall Nusselt number for convective and total heat transfer under both low and high subcooling cases. The comparison of the developed correlations, based on scaling, are made for the wall superheat between 290 and 1100 °C and jet velocity of water between 0.4–3.2 m/s along with the variation of water subcooling between 5 and 45 °C. The proper coefficient of the scaling is developed by making overall comparison of the data from the analysis with experimental data to predict the heat transfer. The effect of liquid to vapor viscosity ratio indicates a substantially higher Nusselt number for the jet impingement of plate under film boiling condition. The density ratio influences the heat transfer only at low subcooling condition. A lower Jakob superheat number, higher Jakob liquid subcooling number, and higher jet Reynolds number increases Nusselt number.

A review on latest development in heat transfer through porous media in combination with nanofluids and wavy walls

Heat flow through porous media and different phenomenon in these media are studied widely in recent years due to their extraordinary applications in different fields of engineering, bio-engineering and energy systems etc. In this report, recent advances in the numerical investigation of completely or partial filled porous media alone or in combination with wavy walls and nanofluids/nanoparticles have been reviewed. The main emphasis of this is to review the theoretical and numerical aspects of the effect of position of porous insert, nanoparticle volume concentration and the amplitude of the waves associated with wavy channels on the Nusselt number, pressure drop, entropy generation and efficiency of heat transfer. The conditions which define the boundary for the use of LTE (Local thermal equilibrium) and LTNE (Local thermal nonequilibrium) equations for evaluation of the porous media have also been reviewed. The LTE equations were found to be appropriate for the systems in which the temperature different between the solid and fluid phase is very small whereas, if the temperature difference between the two is large, then only LTNE can be employed. The porous media along with wavy walls and nanofluid combinations was found to exhibit better results in terms of Nusselt number and heat transfer efficiency but to obtain bets results, minimum amplitude in case of wavy walls and volume concentration of nanoparticle concentration should be optimized.