Average Nu Number Research Articles

Effect of internal crossflow on impingement cooling flow and heat transfer characteristics

The flow and heat transfer characteristics of a single-row impingement jet, fed by internal crossflow, are numerically investigated. The results showed that the internal crossflow propels a rapid coolant outflow on the leeward side of the hole, subsequently elevating the local impingement Reynolds number. Concurrently, the internal crossflow augments the heat transfer rate on the impingement target surface, with surges reaching up to 60 % in the local Nu number and 11 % in the average Nu number at low external crossflow. Counter-intuitively, the heat transfer enhancement due to the increase in local Reynolds number diminishes as the strength of the external crossflow increases. This phenomenon is attributed to the emergence of an in-hole counter-rotating vortex pair, whose interaction with the external crossflow induces elongation of the jet in the pitchwise direction. However, these enhancements in heat transfer rate are counterbalanced come at the expense of a more complex flow structure and higher flow losses. The weight of the internal and external crossflow on impingement cooling performance is also investigated using the overall thermal efficiency which considers both heat transfer and flow resistance and it is found that the external crossflow is the main culprit for the decrease in overall thermal efficiency.

Thermal performance of nanofluid natural convection magneto-hydrodynamics within a chamber equipped with a hot block

In this study, flow and free convection thermal performance within a chamber in the presence of a permanent magnetic field are simulated. Boussinesq approximation and the Lorentz force equation are used for the density variation in free convection, and the magnetic field, respectively. The steady-state, two-dimensional, and incompressible governing equations are simulated using the Semi-Implicit Method for Pressure Linked Equations (SIMPLE). The present study is simulated for different Rayleigh numbers (Ra) corresponding to the situation where the conduction mechanism was predominant (Ra = 100) and the convection heat transfer was predominant (Ra = 105). Also, different intensities of the magnetic field (0 ≤ Ha ≤ 40) and different directions of the magnetic field along with the effects of three different nanoparticles Ag, Cu, and Al2O3 are given. The present study showed that in the case of the dominant convection mechanism, the presence of the magnetohydrodynamics (MHD) condition decreases the Nusselt number (Nu). However, if the conduction is predominant, the applied magnetic field improves the average Nu number. The optimum state for the magnetic field strength was found in the low Rayleigh number. The presence of nanoparticles also intensifies the magnetic field effects. In the high Rayleigh number, the heat transfer rate reduces by 13.5% with the increase of the Hartmann number.

Local heat transfer measurements of the fin on the blade crown by infrared thermography

Current research on heat transfer of the labyrinth surface mainly focuses on the whole structure made of the same material, but the heat conduction from the tip to the root will affect the measurement of the heat transfer coefficient. To minimize the influence of heat conduction, copper strips are embedded on the surface of the fin made of bakelite. The inverse heat transfer problem is solved using the temperatures collected by an infrared thermal imager to determine the local convective heat transfer coefficient. The error of the lumped parameter method is smaller compared to the differential solution. Constant heat flux experiments are used to validate the experimental results, and numerical analysis is performed to analyze the heat transfer mechanism. The flow field, the Nu number distribution, and fitting correlations of the fins are obtained. By comparing and analyzing the heat transfer coefficients obtained by the three methods, it is found that the lumped parameter method can eliminate the influence of heat conduction on the surface. Taking the lumped parameter method as a reference, the errors of stable heat flow and numerical calculation were 21 % and 4.7 %, respectively. Due to the influence of the vortex direction, the Nu number distribution along the height of the windward surface of the second fin is different from the others. The Nu number distribution along the x-direction on the top surface of the fin is similar to the tip of the windward surface. Along the flow direction, the average Nu number on the top surface of the first fin is 1.2 times that of the second one.

Finite element method for natural convection flow of Casson hybrid (Al2O3–Cu/water) nanofluid inside H-shaped enclosure

The fundamental problem in electronic cooling systems is the implementation of a cavity such that it can be used to provide localized cooling to specific components, such as CPUs or GPUs, enhancing their performance and longevity. It can also be used in microfluidic devices for controlled drug delivery, where precise control of fluid flow is crucial. The present article numerically explores the free convection non-Newtonian Casson hybrid nanofluid phenomena that occur within an H-shaped cavity while heated from the middle. The heating efficiency and heat flow in a cavity are influenced by perpendicular hot walls that connect two vertical closed channels. A numerical solution is obtained by implementing the Galerkin finite element method to solve the partial differential equation. The numerical outcomes are depicted on the contour of streamlines and isotherms for different parameters in the following ranges: 0.1 ≤ η ≤ 0.4, 0.005≤ϕhp≤0.020, 0.1 ≤ γ ≤ 2, and 103 ≤ Ra ≤ 106 at fixed Pr = 6.2. In addition, line graphs show rate of heat transfer within the enclosure using the average Nusselt number for these parameters. Increased aspect ratios (η = 0.4) result in a minimal rate of heat transfer enhancement, whereas decreasing η leads to a significantly higher average Nusselt number and maximum heat transfer within the cavity. The convective rate of heat transfer increases with the presence of hybrid nanoparticles inside an H-shaped cavity for all Rayleigh numbers. The rotation of the Casson hybrid nanofluid also rises as the volume ratio of nanoparticles increases. For a fixed aspect ratio (A.R) of 0.1, the heat dissipation is 6.91% at a lower ϕhp value of 0.005 at a fixed Ra value of 105. However, it increases to 7.072% for a higher ϕhp value of 0.02 at Ra = 105. With increasing Ra number, ϕhp, and γ, the number NuAve increases.

Two-phase analysis of heat transfer of nanofluid flow in a wavy channel heat exchanger: A numerical approach

The heat transfer improvement by using CuO/water nanofluid (NF) in a wavy channel is evaluated numerically using the turbulent two-phase mixture and the κ - ε models. The numerical work is a 2-dimensional model created and analyzed in Gambit and Ansys Fluent software, respectively. The flow Reynolds (Re) numbers of 8000 – 40,000, wavelength ranging from 0 – 0.4 m, and solid volume fraction (SVF) of 0 % to 4 % are investigated. In all cases, a constant heat flux of q′′=5000 W/m2 is applied on the outer surface of the heat exchanger. The heat transfer and fluid flow were analyzed by the flow visualization method and heat transfer evaluation indexes. The results show that by increasing the Re number, the vortices increase and more turbulence are generated in the vicinity of the waves near the channel inlet. As the amplitude of the channel waves increased, the velocity at the top of the wave increased, and the resulting pressure gradient behind the wave is intensified and the reverse flow is generated. The improving effect of using NF is more prominent where the effect of other enhancing factors is weak. For wall amplitude of 0.1 m, by increasing the SVF from 1 – 4 % the average Nu number (Nuavg) increased by 35 % and 22 % in Re = 8,000 and 40,000, respectively.

Effect of ferro nanofluids on mixed convection in an open cavity with phase change material

Numerical analysis of mixed convection flow in an open channel cavity was performed by placing PCM and using ferro nanofluids (water based Fe3O4 nanofluid) with different volume fractions (1.0%, 3.0% and 5.0%) as working fluids. The effect of different Richardson numbers under laminar flow conditions with constant Reynolds number was analyzed to reveal how the nanofluid volume fraction and PCM position in the cavity affect the flow and heat transfer characteristics. The main reason for considering the use of nanofluid as a working fluid with the PCM layer is the thermal control of the cavity. It has been determined that the use of ferro nanofluids has a positive effect on the thermal control of the flow by increasing the thermal energy storage capacity of the PCM. As the Ri number increased, the importance of mixed convection effects increased, and for the highest Ri number, natural convection played a dominant role, causing a 65.5% decrease in the heated wall dimensionless temperature. Since the heat flux applied for pure water at highest Ri number is one third of that applied for 5.0% nanofluid, the specified temperature increase is quite lower by comparing heat flux thanks to the nanofluid high convection capability. Different than pure water, in all PCM cases the rate of melting is higher for 5.0% ferro nanofluid due to the higher convective heat transfer. In the case of the PCM on the bottom wall, the highest thermal energy storage capacity was obtained for each working fluid and 50% more energy was stored compared to the right heated wall at the same Ri number. Moreover, the maximum average Nu number was determined for the bottom heated case and for the same Ri number at 5.0% ferro nanofluid which was obtained approximately twice as much as pure water when flow reached steady state.

Influence of a Built-in Finned Trombe Wall on the Indoor Thermal Environment in Cold Regions

This study focuses on energy conservation, reducing the amount of energy consumed to heat a room, and decreasing the intensity of carbon emissions. The research object is a room heated by a floor with a built-in finned Trombe wall (TW) located in Lanzhou, Gansu Province. ANSYS software was employed to conduct a simulation study on parameters such as fin height, transverse spacing, longitudinal spacing, arrangement mode, and fin apex angle. The simulation results were used to determine the fin parameters’ thermal impact on the TW’s thermal performance, including with respect to a room’s thermal environment (TE). The results show that the heat transfer performance of a TW with respect to the thermal environment of a room is the greatest when the height of the heat-absorbing surface is 20 mm, the transverse spacing is 0.20 m, the longitudinal spacing is 0.533 m, and in-line 90° top-angle fins, that is, isosceles right triangle fins, are used. The average Nu number of the fin-type TW is 154.75. Compared with the average Nu number of the finless TW, which is 141.43, the average Nu number increases by 13.32 due to the addition of fins. The optimized fin-type TW has 7.77% higher convective heat supply efficiency than the finless TW. Although the PMV-PPD results of the two TW-type rooms are not very different, the comfort period of the fin-type TW room is longer. At the same time, the LPD3 of the non-finned TW and the finned TW rooms is less than 10%, the wind speed at the head and ankle is less than 0.12 m/s, the air gust sensation is not strong, and the thermal comfort is good, indicating that the addition of fins is beneficial to the improvement of indoor thermal comfort. Compared to standard rooms, finless TW rooms and fin-type TW rooms have energy-saving rates of 36.38% and 44.63%, respectively. Thus, fin-type TW rooms’ energy saving rate is 8.25% higher, resulting in effective savings in heating energy consumption. Therefore, the indoor TE and auxiliary heating conditions are improved, and the integration of solar building technology can be facilitated, which offers significant reference value for energy transformation.

Experimental investigation of water vapor condensation from flue gas in different rows of a heat exchanger model

Condensing heat exchangers (HE) are used in many applications because of their usability with different fluids and a wide operating range in terms of pressure, temperature and power. Despite that, the thermal design of condensing heat exchangers is still not optimized, due to the complexity of the condensation process and lack of related research.This paper presents results of experimental investigations of biofuel flue gas water vapor condensation on vertical tubes in different rows of a tube bundle in a crossflow. The effects of water vapor mass fraction, inlet flue gas temperature and the Reynolds number on heat transfer when the inlet cooling water temperature and flow rate are constant were analyzed. The results obtained showed that the main parameters which had the most influence on the condensation process were the water vapor mass fraction in the flue gas and its temperature at the inlet to the test section. In the range of inlet flue gas Reynolds numbers investigated, the Re effect on heat transfer was not as significant as the effect of the parameters indicated above. However, the Re number had some influence on the heat transfer variation along the inline tube bundle. A comparison of the average Nu number in the case of dry air with the experimentally determined average Nu number, even with low condensable gas mass fraction (6 %), showed that it increased considerably. A correlation was proposed, which helps to determine the average Nu number for the heat exchanger in the range of experiments performed.

Investigation of effect of cooling water characteristics on flue gas condensation along vertical tube heat exchanger

Flue gas condensing heat exchangers obtain the highest thermal efficiency of power boilers through the recovery of sensible and latent heat of condensation from flue gases containing certain amount of water vapor. Many parameters influence the operation of economizers, among them the amount of water vapor in the flue gas and cooling water parameters. This paper presents experimental results obtained for various local parameters of vertical tube bundle economizer when the flue gas water vapor mass fraction is 6 % and 14 % and when different cooling water inlet flow rates and temperatures are applied. The results showed that the change in the water flow rate had negligible effect on variation of the local flue gas and cooling water temperature along heat exchanger. However, its effect on the condensate flux and the local Nusselt number was significant. The cooling water temperature and, especially, water vapor mass fraction had a great impact on the average Nu number, but the effect of the flue gas Re number was less evident. It was determined that there exists a ratio of cooling water to flue gas mass flow rate, where the operation of the economizer is optimal in terms heat transfer and condensation efficiency.

Studying Alumina–Water Nanofluid Two-Phase Heat Transfer in a Novel E-Shaped Porous Cavity via Introducing New Thermal Conductivity Correlation

Investigating natural convection heat transfer of nanofluids in various geometries has garnered significant attention due to its potential applications across several disciplines. This study presents a numerical simulation of the natural convection heat transfer and entropy generation process in an E-shaped porous cavity filled with nanofluids, implementing Buongiorno’s simulation model. Analyzing the behavior of individual nanoparticles, or even the entire nanofluid system at the molecular level, can be extremely computationally intensive. Symmetry is a fundamental concept in science that can help reduce this computational burden considerably. In this study, nanofluids are frequently conceived of as a combination of water and Al2O3 nanoparticles at a concentration of up to 4% by volume. A unique correlation was proposed to model the effective thermal conductivity of nanofluids. The average Nusselt number, entropy production, and Rayleigh number have been illustrated to exhibit a decreasing trend when the volume concentration of nanoparticles inside the porous cavity rises; the 4% vol. water–alumina NFs yield 17.35% less average Nu number compared to the base water.

Experimental study on air impinging jet for effective cooling of multiple protruding heat sources

Air Impinging Jet is an effective cooling method for various applications, ensuring optimal performance and reliability of heat-generation systems. In the present work, a novel technique of cooling discrete protruding heat sources mounted in a rectangular channel by using a double air jet is introduced experimentally. A constant and uniform heat flux is produced from protruding heat source surfaces where the bottom and the upper channel walls are insulated. The effects of various parameters on the heat source cooling performance such as the Nusselt number for single and double air jets are obtained. Various parameters such as the air Reynolds number, aspect ratio, double jet position ratio, and jet inclination angle are investigated. The results show that those parameters effectively affect the average temperatures and the standard deviation of all protruding heat sources. It is indicated that the maximum value of the average Nu number occurs at the heat source just underneath the impinging air jet compared to other downstream heat sources. The highest average Nu is achieved at a position ratio of 3/7 and an inclination angle of 10o. The cooling system accomplishes an acceptable Nu and temperature uniform distribution for a position ratio of 4/7 compared to the other position ratios. The improved performance and longevity of heat sources are achieved by the innovative double-air jet method, which archives a consistent temperature distribution for all projecting heat sources.

Comparative evaluation of oscillatory behavior and cooling performance of twin and single self-excited jets in a confined heated enclosure

This study presents numerical simulations to investigate the oscillatory behavior and cooling performance of twin self-excited impinging jets in a heated enclosure. Simulations were carried out by a computational code developed on the OpenFOAM platform, and the shear stress transport (SST) model was used to consider turbulence characteristics. Flow field characteristics are evaluated at different nozzle spacing-to-width ratios S/e of 0, 3, 6, and 9 and inlet flow rates (Q) of 0.04, 0.06, and 0.08 m3/s. The effects of S/e and Q on the flow pattern, oscillation frequency, and the average Nusselt number Nuave on the enclosure’s impingement wall were examined. Results showed that, for S/e≤6, the two jets merge and oscillate as an equivalent single jet, while for S/e>6, two jets oscillate with the same frequency but are unsynchronized. The results also indicated that at Q=0.04m3/s, the use of a twin jet with S/e=0 can increase the Nuave by 12% compared to a single jet. By increasing the flow rate, the cooling performance of these two jets becomes more similar. The study found that increasing the nozzle spacing at a constant flow rate does not significantly affect the oscillation frequency, but it can reduce Nuave by about 50%.

CFD simulation of effect spacing between lithium-ion batteries by using flow air inside the cooling pack

The CFD simulation of this study shows the impact of airflow with varying Reynolds numbers on heat transfer improvement with cooling lithium-ion batteries at varied battery row spacing. Air was used as a cooling fluid to remove heat from lithium-ion batteries by flowing within the cooling pack during testing of four different spacing ranges (S = 1–4 mm). The Reynolds numbers vary from15,000 to 30,000 in the current analysis. The average Nu numbers are augmented through increasing Reynolds numbers for all types of cooling fluids. The CFD results show that the Nu number increases as spacing increases. The temperature of the single cell drops with increasing the Re or the flow rate since the liquid in the pack exchange with a new cold HTF at a faster rate. The average Nu number is directly proportional to the Re number and the spacing between the neighbor cells. Further, the temperature of the cells located closer to the inlet section is always lower than those closer to the outlet section because of the temperature differences between the cells and the HTF. This study has confirmed that the flowing air with high Re and highest spacing S = 4 mm has a major impact on thermal dissipation and rapid heat transfer improvement from lithium-ion batteries in the cooling pack, which leads to improved electrical performance and increase the life of lithium-ion batteries.

Experimental investigation of heat transfer characteristics of magnetic nanofluids (MNFs) under a specially designed revolving magnetic field effect

This study investigated the heat transfer characteristics of magnetic nanofluids (MNFs) under external magnetic field effects. Magnetic nanofluids used in the experiments were synthesised with Fe3O4 (iron oxide) nanoparticles (at mass ratios of 0.5, 1, and 2 %) in deionised water. Then, the thermal conductivity and viscosity values that directly affect the heat transfer results were measured after a comprehensive study on the stability of magnetic nanofluids. A unique set of experiments was designed to determine the effects of magnetic fields on different magnetic nanofluids. This system, which creates a rotating magnetic field effect, can be used stationary and with the effect of revolution at a certain speed. Heat transfer experiment results were evaluated considering average Nusselt numbers obtained from 3500 to 15,000 Reynolds numbers. The magnetic field acting on the magnetic nanofluids in heat transfer experiments was investigated for three circumstances. It was determined that the increasing rates of average Nu numbers in magnetic nanofluids with mass ratios of 0.5, 1 and 2% under the influence of constant magnetic field effects were 25, 38, and 60%, respectively, compared to deionised water. Moreover, when the magnetic field effects were constant, the increasing rates of average Nu numbers obtained 15, 20, and 33% in nanofluids with mass ratios of 0.5, 1, and 2%, respectively, compared to the case without magnetic field effects.

Effects of isothermal-adiabatic boundary conditions on the transition characteristics in two-dimensional turbulent Rayleigh–Bénard convection

In this article, two-dimensional (2-D) Rayleigh–Bénard (RB) convection with isothermal-adiabatic boundary conditions is simulated by using the double distribution function approach of lattice Boltzmann method. The effects of isothermal-adiabatic boundary on the flow and the heat transfer characteristics in the RB system under instability, transition and turbulence are discussed in detail. The effect of the isothermal-adiabatic boundary on the scaling of Nusselt (Nu) number as a function of Rayleigh (Ra) number is analyzed. The 0.3 scaling is observed in the mixed boundary system when the Ra number is in the range of 107–108. The scaling is well consistent with that in the RB system with uniform boundaries. A comparison of the influence on the root mean square of Nu number between uniform isothermal boundary and isothermal-adiabatic boundary demonstrates that in both “transition” region and “turbulence” region, the intensity of the fluctuation of average Nu number at uniform isothermal boundary is higher than that at the isothermal-adiabatic boundary. The comparison of the fluctuation of the average Nu number between “transition” region and “turbulence” region shows that the isothermal-adiabatic boundary has a better suppression effect on the fluctuation of heat transfer in the “transition” region. The supression is related to ratio of the scale of plume and the “heat source core.” When the scales are comparable, the fluctuation of average Nu number will be significantly suppressed. Flow field and temperature field further show the plumes are generated at these “heat source cores,” which effectively supports the “heat source core” assumption.

Free convection analysis for a nanofluid in a wavy porous domain subject to shape of nanoparticle and internal heat generation

Natural convection takes up the attention of researchers due to its expansive industrial and engineering utilizations i.e., heat exchangers and electronic cooling. In this work, free convection of Cu-H2O nanoliquid flow and heat transfer (HT) in porous circular wavy domain under the internal heat generation has been perused by finite element method (FEM). The shape factor of nanomaterials is also considered. The influences of active factors like Rayleigh number Ra, nanofluid concentration, wavy wall’s contraction ratio A, number of undulations D, and shape factor of nanomaterials m are explored on flow and HT specifications. Moreover, the correlations for average Nusselt number Nuave have been attained with regard to impressive parameters of current study. Findings show that Nuave soars with soaring nanofluid concentration and nanoparticles’ shape factor. Further, the outcomes characterize that Nuave may lessen up to 15.11% and 9.95% by detracting A from 0.1 to 0.3 and by mounting D from 4 to 12, respectively.

A study on microchip cooling performance increment by using air jet impingement with one and double rows

The impinging jet technique is a high-performance cooling technology for microchips which are basic elements of computer systems and have high heat generation rates in small volumes. In this study, the improvement of heat transfer of the desktop microchips used in all technological products today by air-impinging jet flow was examined. For this purpose, numerical research was carried out on the cooling of copper plate surfaces with two different patterns, concave and roof shaped having 1000 W/m2 constant heat flux in rectangular cross-sectional ducts by one and double air jets with distances of Dh and 2 Dh between them. Numerical analysis was performed steady and in three dimensions with the k– ε turbulence model by the Ansys–Fluent program. The obtained results were compared with the numerical and experimental results of the study in the literature and it was seen that they are determined to be compatible. The results were presented as the mean Nu number for each of both patterned surfaces and the mean outlet temperature of the jet flow ( Tmoj) and the mean Nu number ( Num) of all patterned surfaces in single and double jet channels with different distances. Besides, pressure drop (Δ P), friction factor ( f), thermal resistance ( Rt) and thermo-hydraulic performance (THP) of concave and roof-patterned surfaces in the channels with different jet setup configurations were analyzed. Streamline and temperature contour distributions of the jet flow along the channel for different H/ Dh ratios and jet numbers were evaluated for both patterned surfaces. In H/ Dh = 4 and at Re = 7000, the average Nu number for roof-patterned surfaces was found to be 30.52% higher than concave patterned surfaces in the case of double jets with a distance of Dh. Rt reduction values of the roof and concave pattern surfaces with a double jet arrangement having 2 Dh distance at Re = 5000 and H/ Dh = 8 are 163.7% and 36.23% when compared to single jet, respectively.

Effects of different working gases on the heat transfer enhancement performance of a heating tube with spiral insert under oscillatory flow

The working gas type had an important effect on the heat transfer performance of the turbulence device in the heater of Stirling engine, but the related researches were scarce, especially under the oscillatory flow. This work investigated the effects of four working gases (i.e., H2, He, N2, and CO2) on the heat transfer characteristics of a heating tube with spiral insert compared with a smooth tube under oscillating flow for a Stirling engine. The transient physical fields under different phase angles in an oscillatory cycle were analyzed, and the Nusselt (Nu) number, pressure loss and outlet temperature of working gas were studied. The results show that the cycle average Nu number of the enhanced tube with H2, He, N2, and CO2 as working gas increased to 1.67, 1.62, 1.61 and 1.72 times when comparing with those of the smooth tube. The cycle average friction coefficient increased to 1.96, 2.37, 2.36 and 2.62 times, respectively. Moreover, the performance evaluation criterion (PEC) values of the enhanced tube using the four types of working gas were all greater than 1 (1.21∼1.33). This implies that the comprehensive heat transfer performance of the heating tube with spiral insert was all improved with the four types of working gas. Moreover, the heat transfer enhancement effect was best when hydrogen was used. While considering the thermodynamic performance and safety reliability, the helium was more recommended. The findings are beneficial to enhance the operating efficiency of a Stirling engine.

Thermal performance assessment by using a wavy porous obstacle in a circular vented cavity under non-uniform magnetic field during forced convection of hybrid nanofluids

In this study, effects of using a wavy porous object on the thermal performance improvement in circular vented cavity are numerically assessed during hybrid nanofluid convection under non-uniform magnetic field. Numerical analysis is conducted for varying values of Reynolds number (Re, between 200 and 1000), Hartmann number (Ha between 0 and 50), magnetic field inclination (γ between 0 and 90) while Darcy number is taken between and . The amplitude is considered between 0 and 0.5 while wave number of the corrugated porous object is taken between 2 and 16. Significant impacts of the porous object parameters and permeability on the flow pattern distribution and thermal performance improvements are obtained. The magnetic field improves the heat transfer for the lower permeability object case at Ha = 10 while the average Nusselt number (Nu) is reduced for the case with higher permeability object case. Average Nu number improvement up to 33.5 is obtained with the imposed non-uniform magnetic field effects. Average Nu variations of 27.3 and 15 are obtained when the corrugation wave number and amplitude are varied. The Constrained Optimization BY Linear Approximations optimization is used to achieve the highest thermal performance of the configurations.

Research of cooling performance in combined jet flow channels using different nanofluids

In this work, heat transfer from the cube and circular hollow-shaped copper plate surfaces with a constant heat flux of 1000 W/m2 was numerically investigated by using a combination of the cross-flow-impinging jet. Numerical research was performed by solving the energy and Navier-Stokes equations as three-dimensional and steady, using the Ansys-Fluent computer program with the k-ε turbulence model. In order to direct the combined jet flow in the channel to the heated surfaces, the fins with 30o and 60o angles were placed in the channel horizontally with the impinging jet surface. While the channel height ( H) is 4D, the distance of the fin from the jet inlet ( N) is 2D. Fluids used in the channels are water, 0.02% GO-water and 2% diamond-water. The upper and lower surfaces of the channel and the fin are adiabatic and the flow Reynolds number range is 5000–15,000. The results of the work were compared with the experimental results of the studies in the literature and they were found to be consistent with each other. The results were presented as the mean Nu number and mean surface temperature variations for each model surface. Besides, the velocity and temperature contour distributions of the combined jet flow along the channel for diamond-water nanofluid were evaluated. Also, performance evaluation coefficient and average Nu number (Num), and surface temperature values (Tm) were evaluated at different Reynolds numbers for all three patterned surfaces in the channels. At Re = 15,000, there are 18.42% and 17.08% increments in Num value for cube and circular hollow model surfaces in the channel with 60o fin and GO-water nanofluid compared to the channel with water flow and without fin.