High Heat Transfer Performance Research Articles

Unsteady Numerical Investigation Strategy of Natural Convection in an Isosceles Superimposed Triangular Enclosure

In energy applications, convection plays a dominant role in the transport of energy for the proper design in order to achieve higher heat transfer rates. Where the fluid motion is simply induced by density gradients. This study is concerned with transient natural convection in an isosceles-superimposed triangular enclosure. The inclination of the inclined partitions walls was θ =45°. Critical Rayleigh numbers have been obtained: Ra=106, especially for the fluid crushed between the two triangles where we can visualize the critical convection transaction between the air and water. The results in quantitative measurement of average Nusselt number change and qualitative visualization of streamline and isotherms are examined. The air and water streamlines and the temperature fields were obtained for the Rayleigh numbers 103 ≤ Ra ≤ 108 for both cases studied. Besides, the highest heat transfer performance is observed during the natural convection case of the water fluid, and the lowest heat is transferred when the fluid is dilatant. The triangular shape can greatly enhance the heat transfer from the bottom to the top at first in a smooth and harmonious manner, and then it turns into a more complex and disorderly shape when the water reaches high temperatures.

Effect of wall curvature on heat transfer and hydrodynamics in a ribbed cooling passage

Simplified rectangular ribbed cooling passages with a flat wall are extensively considered in exploring the internal cooling features of turbine blades, but the realistic blade has a twisted shape inherently. The effects induced by the curved wall have not been clarified in detail. In this work, adopting a verified v2f turbulence model, numerical investigations are completed to evaluate the effects of the curved wall on the internal cooling characteristics of a ribbed channel. Adopting the unified ribbed channel, flat, convex, and concave walls with distinct curvatures are comprehensively evaluated and compared in a wide Re range for the turbulent flow and heat transfer features as well as the flow and thermal performance. It is found that using the flat wall, ribs can typically induce recirculation vortices having a two-dimensional nature. In contrast, the curved wall significantly contributes to the counter-rotating vortex pairs on the spanwise plane. Combined with recirculation vortices offered by the ribs, the turbulent flow of the cooling channel with the curved wall has a remarkable three-dimensional feature. Hence, the turbulent activity and fluid mixing are enhanced greatly along with the raised heat transfer enhancement and friction loss. Particularly, the convex wall with a curvature of K = 4 provides 28.6 % higher heat transfer performance (Nu/Nu0) but 88.4 % higher resistance (f/f0) than the flat wall. Considering the overall cooling performance, the concave wall with a relatively small curvature is suggested with an improvement of up to 32.8 % concerning the factor (Nu/Nu0)/(f/f0) and 9.5 % on (Nu/Nu0)/(f/f0)1/3. Finally, it is highlighted that considering the effect of the wall curvature, the current study stimulates the mechanistic understanding and provides a design guideline for high-performance blade internal cooling.

Experimental and simulation study on a zeotropic ORC system using R1234ze(E)/R245fa as working fluid

Organic Rankine Cycle (ORC) is a highly promising technology for converting heat to power, which has a widespread application in renewable energy utilization and waste heat recovery. Zeotropic working fluids are widely investigated to enhance the performance of ORC. In the present study, an experimental study on zeotropic mixture R1234ze(E)/R245fa is conducted under specified operating conditions and the operating behaviors of the ORC system are evaluated. An ORC simulation model (BP-ORC) based on a back propagation neural network and heat exchanger simulation modules is developed. The contribution factors that trigger the differences in heat transfer and system performance among the various working fluids are investigated. The operating behaviors of the heat exchangers and system are simulated for the working conditions beyond the experimental study. R1234ze(E)/R245fa (0.25:0.75 and 0.50:0.50) features a wider operating range of mass flowrate than R245fa due to their relatively lower density. The net power output of R1234ze(E)/R245fa (0.50:0.50) is 4.63 % higher than that of R245fa at a mass flow rate of 0.164 kg/s due to its relatively higher heat transfer performance. The variation of density and operating pressure plays a significant role in influencing the heat transfer behaviors and system performances.

Elliptical vibration chiseling: a novel process for texturing ultra-high-aspect-ratio microstructures on the metallic surface

Highlights Elliptical vibration chiseling is proposed based on a game-changing process principle for the high-efficient texturing of ultrahigh-aspect-ratio surface microstructures. Uniformed microstructures with an aspect ratio of 2–12 in the spacing scale of 1–10 μm have been successfully fabricated using elliptical vibration chiseling. The developed process model of elliptical vibration chiseling has been verified by the measured results of the microstructures’ geometric parameters. An inclined elliptical trajectory of tool vibration is more suitable for elliptical vibration chiseling than the standard elliptical trajectory. The deterministic process effects on the surface generation of microstructure in elliptical vibration chiseling have been demonstrated.

Thermal energy storage system based on nanoparticle distribution optimisation for enhanced heat transfer

As a new type of heat transport medium with high efficiency and high heat transfer performance, nanofluids can effectively improve the heat transfer performance of thermal systems. In this paper, a lattice Boltzmann method is employed to propose a novel thermal storage system with optimised nanoparticle distribution using spacer-separated nano-enhanced PCM with spacer arrangement. The thermal energy storage units are separated by thermal insulation and heated by means of thermally conductive fluid channels. The effects of Rayleigh number, volume fraction and layout pattern are investigated. It is shown that the larger the Rayleigh number is, the more intense the reaction of the heat storage system is; it is concluded that the strong convection phenomenon in the upper left side region is more than that in the lower left side, and the volume fraction in the lower left side can be reduced to enhance the efficiency of this heat transfer in order to achieve a faster melting rate. The various distributions studied in this paper all have the effect of accelerating the melting rate to varying degrees compared to Type 1. The present study shows that increasing the volume fraction of phase change material in the upper left side of the square cavity has a promoting effect on the melting rate when compared to the lower side, and the larger the difference between the two, the better the effect is.

FLOW BOILING HEAT TRANSFER IN MICROCHANNEL HEAT EXCHANGERS WITH MICRO POROUS COATING SURFACE

This study experimentally investigated the heat transfer and pressure drop performance of refrigerant HFC-245fa flow boiling in microchannel heat exchangers with and without microporous coating. The flow boiling heat transfer performance at various mass fluxes, heating rate, exit vapor qualities, and surface coating thickness was compared. The test results showed that the 52 μm coating thickness porous surface exhibited 65-148% higher heat transfer performance than the smooth surface, while the 98 μm microporous coating surface showed a lower improvement of 41-90% at various mass fluxes. Partial dry out was observed at high and moderate mass fluxes on both smooth and porous coating channels. It happened at lower exit vapor qualities in microporous coating channels than that in smooth channels. The partial dry-out exit vapor qualities increased with decreasing mass fluxes. For the lowest mass flux, because of the low heat flux and low nucleation suppression, no significant partial dry out was investigated. The pressure drops in microporous coating channels were around 25-47% higher than those in smooth channels. There was no significant influence of microporous coating layer thickness on flow boiling pressures drops.

Experimental study on flow boiling of HFE-7100 in rectangular parallel microchannel

With the rapid development of microelectronic technology, the integration and power of chip are increasing. Heat dissipation with high heat flux in limited space has become a bottleneck restricting the efficient and stable operation of the microelectronic devices. Flow boiling in microchannel heat sink is one of the most essential candidates for solving this problem. It has been shown that remarkable high heat transfer performance can be achieved through the liquid-to-vapor change process, which can dissipate a large amount of heat from a small area. In addition, dielectric fluorinated fluids, such as HFE-7100, HFE-7200, and FC-72, are especially suitable for cooling microelectronic devices, because of their excellent safety and environmental characteristics. However, dielectric fluorinated fluids have poorer thermophysical properties than water. Thus, the flow boiling heat transfer characteristics of dielectric fluorinated fluids can be different from those of water. In this work, flow boiling heat transfer and flow characteristics of HFE-7100 in a rectangular parallel microchannel are investigated. The tests are conducted at mass fluxes from 88.9 to 277.8 kg·m<sup>–2</sup>·s<sup>–1</sup>, inlet subcooling temperature from 20.5 to 35.5 ℃ and effective heat flux from 12 to 279 kW·m<sup>–2</sup> at nearly atmospheric pressure. The effects of mass flux, inlet subcooling temperature, effective heat flux and vapor quality are examined and analyzed. Additionally, flow visualization is also obtained to explain the heat transfer mechanism during the experiments. The results show that the boiling hysteresis is observed for HFE-7100 at low inlet subcooling temperature, and the increasing inlet subcooling temperature and mass flux can delay the onset of nucleate boiling. The increases of inlet subcooling temperature and mass flux can enhance the two-phase heat transfer coefficient. And the two-phase heat transfer coefficient is significantly dependent on the inlet subcooling temperature in the slug flow, while it is significantly dependent on the mass flux in the annular flow. The two-phase pressure drop increases drastically as the effective heat flux increases. And the two-phase pressure drops with different mass fluxes at constant vapor quality are obviously different between the slug flow and the annular flow. Furthermore, the experimental data are compared with four predicted values of the literature. It is found that the correlation of Lockhart has the best statistical agreement with an MAE of 19.6% and over 85% of points in the deviation bandwidth of ±30%. The results in this paper give valuable theoretical guidance for designing and optimizing heat dissipation equipment for microelectronic devices. By utilizing HFE-7100 as the coolant and microchannel heat sinks in flow boiling, it is possible to enhance the stability and reliability of the electronic devices. Additionally, the heat transfer performance associated with different heat fluxes can be improved by regulating the inlet subcooling and mass flow rate. Finally, the two-phase pressure drop correlation proposed by Lockhart can be employed to predict the pump power for heat dissipation equipment.

Numerical Study and Structural Optimization of Impinging Jet Heat Transfer Performance of Floatation Nozzle

A floatation nozzle can effectively transfer heat and dry without touching the substrate, and serves as a vital component for heat transfer to the substrate. Enhancing the heat transfer performance, and reducing its heat transfer unevenness to the substrate play an important role in improving product quality and reducing thermal stress. In this work, the effects of key structural parameters of the floatation nozzle on the heat transfer mechanism are systematically investigated by means of a numerical simulation of computational fluid dynamics. The findings demonstrate that the secondary vortex structure induced by the floatation nozzle with effusion holes increases heat transfer performance by 254.3% compared with the nozzle without effusion holes. The turbulent kinetic energy and temperature distribution between the jet and the target surface are affected by the jet angle and slit width respectively, which change the heat transfer performance of the float nozzle in different degrees. Furthermore, to improve the comprehensive heat transfer performance of the floatation nozzle structure, taking into account the average heat transfer capability and heat transfer uniformity, the floatation nozzle’s design is optimized by the application of the response surface method. The comprehensive heat transfer performance is increased by 26.48% with the optimized design parameters. Our work is of practical value for the design of floatation nozzles with high heat transfer performance to improve product quality in industrial systems.

Numerical evaluation of the heat transfer performance of water-cooled system for electric vehicle drive motor based on the field synergy principle

Thermal management of drive motors is a challenging design for transport electrification industries such as electric vehicles. Due to the high heat transfer performance, water-cooled system have become one of the technologies to meet the needs of these industries. Meeting the synergy between the heat transfer performance of the water-cooled system and the heat generated by the motor is key to taking advantage of the performance of drive motors. This study numerically evaluates and experimentally investigates the heat transfer performance of the electric vehicles drive motor water-cooled system based on field synergy principle, discussing the synergy between the temperature gradient field and velocity field of the water-cooled system under different cooling conditions, and the calculated results are consistent with the test results. By observing the interaction between the fluid vortexes and the main flow, the distribution pattern of the synergy angle in the cooling channels was determined. The results show that when the heat transfer capacity of the water-cooled system reaches its peak, the increase in Reynolds number instead leads to the increase in the average synergy angle of the whole field, which ultimately causes a deterioration of synergy between the velocity and temperature gradient fields.

Thermodynamic optimization in laminar and fully developed flow in double pipe heat exchanger with arrow-shaped extended surfaces: A novel design

An innovative design of extended fins in the form of arrow fins is optimized for high performance heat transfer in a double pipe heat exchanger (DPHX). The arrow fins are designed within the trapezoidal fin to save material, weight, cost and making energy-efficient DPH. The arrow fins are investigated for the first time in DPHX. The FEM approach is used for computational simulation of the present work. A thermal boundary condition of constant heat flux is imposed on the arrow fins and inner pipe assembly. The results are computed in terms of fRe, Nusselt number and j-factor. The results dictate that the geometrical configurations of arrow DPHX for a significant rise in the values of the Nusselt number are: 80 % height of arrow fins is recommended when the number of arrow fins varies from 6 to 24, 20 % height for 30 arrow fins in the case of smaller values of radii ratio (Rˆ). For larger values of Rˆ, 20 % height of arrow fins may be selected for M=6&30, while for arrow fins varying from 12 to 24,H*=0.8 is recommended. On comparison of the thermal performance of the arrow-finned DPHX with the trapezoidal-finned DPHX, the maximum rise of the Nusselt number and j-factor are 113.2 % and 124.2 %, respectively. The proposed design of arrow-finned DPHX has advantages over the design of trapezoidal finned DPHX due to the significant decrease both in manufacturing cost and weight, increased thermal performance, and saving energy.

Machine Learning Assisted Microchannel Geometric Optimization—A Case Study of Channel Designs

At present, microchannel heat exchangers are widely applied in the fields of air-conditioning and heat pumping applications given their high heat transfer performance, compact size, and low material cost. However, designing and optimizing the channel geometries remain challenging, as they require balancing multiple competing objectives to achieve the optimal performance. This study investigates various parameters, including the channel count, wetted perimeter, cross-sectional area, and mass flow rate for each channel, to achieve the optimal efficiency. The optimization objectives include maximizing the heat transfer rate, minimizing the refrigerant convective thermal resistance, maximizing the refrigerant heat transfer coefficient, and minimizing the pressure drop. A multi-objective genetic optimization algorithm, in conjunction with artificial neural network (ANN)-based machine learning models, was used to predict the heat transfer rate to speed up the calculation process during the optimization. We identified that a gradient reduction in the wetted perimeter from the air inlet along the airflow direction could enhance the heat transfer rate. Additionally, the results indicate that an increase in the number of channels leads to an enhanced heat transfer efficiency rate. However, with the increase in the number of channels, the cross-sectional area of each channel is correspondingly reduced to maintain a consistent overall cross-sectional area. This reduction increases the fluid resistance, leading to an increased pressure drop across the system. This observation is critical for a microchannel design optimization, highlighting the importance of attaining a balance between achieving a higher heat transfer efficiency and maintaining a favorable fluid dynamic performance.

An experimental investigation on the heat transfer characteristics of cascaded thermal storage units based on multichannel flat tubes

A latent heat storage unit made of a two-stage phase change material (PCM) can decrease the mismatch between supply and demand of energy. The cascaded phase change thermal storage stores and utilizes energy hierarchically. A two-stage cascaded thermal storage unit based on multichannel flat tubes and compact fins is developed in this study. The device uses water as the heat transfer fluid (HTF). Melting/solidification time, charging/discharging power, thermal efficiency, and exergy efficiency are evaluated for different HTF inlet temperatures and PCM volume flow rates. At the charging conditions of 70 °C and 1.5 L/min, the melting time for paraffin and lauric acid are 21and 20 min, respectively. The thermal efficiencies of the first and second stages of the thermal storage unit are 70.62 % and 70.40 %, respectively, and the exergy efficiencies are 81.25 % and 81.19 %. Given the small pressure loss of the pump and the high heat transfer performance of the heat storage system, using 70 °C and 1.5 L/min as experimental conditions for HTF is the key to obtaining short PCM melting times and high power.

Experimental Investigation on Affecting Air Flow against the Maximum Temperature Difference of a Lithium-Ion Battery with Heat Pipe Cooling

Research on battery thermal management systems (BTMSs) is particularly significant since the electric vehicle sector is growing in importance and because the batteries that power them have high operating temperature requirements. Among them, heat pipe (HP)-based battery thermal management systems have very high heat transfer performance but fall short in maintaining uniform temperature distribution. This study presented forced air cooling by an axial fan as a method of improving the cooling performance of flat heat pipes coupled with aluminum fins (FHPAFs) and investigated the impact of air velocity on the battery pack’s maximum temperature differential (ΔTmax). All experiments were conducted on lithium nickel manganese cobalt oxide (NMC) pouch battery cells with a 20 Ah capacity in seven series connections at room temperature, under forced and natural convection, at various air velocity values (12.7 m/s, 9.5 m/s, and 6.3 m/s), and with 1C, 2C, 3C, and 4C discharge rates. The results indicated that at the same air velocity, increasing the discharge rate increases the ΔTmax significantly. Forced convection has a higher ΔTmax than natural convection. The ΔTmax was reduced when the air velocity was increased during forced convection.

Effects of the ground surface thermal boundary condition on the long-term thermal performance of energy diaphragm walls

Energy diaphragm walls have attracted increasing attention due to their high heat transfer performance. Thus, the factors that affect the thermal performance of energy walls have been investigated to provide insights for further practical applications. Numerical simulation is widely used in energy wall analysis due to the complexity of conducting field tests. Therefore, the choice of boundary conditions in the simulations is crucial; it refers to whether the model reflects reality and has a significant impact on the results. In most cases, the assumed ground surface thermal boundary is not the same (e.g., thermal insulation, constant temperature), and the ground temperature is also assumed to be constant with depth, which may result in a large loss of thermal energy or inaccurate assessment of thermal performance for the energy wall. In this respect, this paper investigates the long-term differences in thermal performance under these boundaries and considers the ground temperature that varies with depth and time, which has not been comprehensively considered before in the analysis of energy walls. The results show that accounting for air temperature or ground temperature variations with depth and time can result in a great increase in thermal performance, e.g., a 34% increase in the cooling thermal load compared with the thermal insulation boundary. In the performed parametric analysis, the results highlight the significant influence of the thermal load and wall height on the thermal differences between these boundaries. These findings provide a reference for choosing ground surface thermal boundaries and better thermal design of energy diaphragm walls.

Review of enhancing boiling and condensation heat transfer: Surface modification

Data centers have tended to develop towards large scale and high density, with overall power consumption reaching up to 3 % of the total national electricity consumption. It is vital to establish energy-efficient electronic cooling devices for data center improvement. Phase-change heat transfer has emerged as a highly efficient method for addressing the heat dissipation problem. As the demand for micro-electronic cooling devices grows, enhancing the phase-change heat transfer has been a key focus of engineering research for several decades. Surface modification can effectively facilitate heat transfer favored by the surface area expansion and free energy transition. This review delved into the multiple processes involved in phase-change heat transfer, containing boiling and condensation. Considering the surface roughness and free energy, the wettability theories and manipulations of hydrophilic and hydrophobic surfaces were presented. The fabrication techniques available for modified surfaces mainly comprise coating, etching, template, sol-gen, and layer-by-layer assembly methods. The effects of patterned surface, wettability gradient surface, electrowetting surface, and wettability controllable surface on phase-change heat transfer enhancement were elaborated, particularly for the critical heat flux and heat transfer coefficients. This review of experimental and simulation results showed that surface wettability modification possesses a promising prospect in improving heat transfer performance. In this review, recommendations for the design of surface modification to promote the development of energy-efficient technologies in specific artificial environments were proposed. Further theoretical and experimental efforts need to create novel surfaces that can facilitate high-performance phase-change heat transfer across a range of applications.

Tube bundle evaporators with LGWP refrigerant R1234ze(E)

With new low-GWP HFO refrigerants, the heat transfer performances and methods for decreasing system refrigerant inventory are receiving increasing interest. In shell-and-tube heat exchangers, refrigerant distribution via pressurized liquid spray has the potential for high heat transfer performance while reducing refrigerant charge. However, no published studies have investigated LGWP refrigerants with spray evaporation on tube bundles. A test apparatus was constructed to measure the shell-side heat transfer coefficients of R1234ze(E) on bundles of tubes with two different enhanced-surface types and in two different bundle geometries at various refrigerant saturation temperatures. The results showed strong dependence on refrigerant properties, tube heat flux, enhanced-surface type, bundle geometry, and refrigerant inlet subcooling. The bundle heat transfer coefficients of R1234ze(E) were similar to that of R134a in the same test setup, usually within ±15% for similar conditions. In both cases, they first increased with the heat flux until a local maximum value was achieved. A localized dryout of the tubes at the bottom of the bundle penalized the overall bundle heat transfer coefficient at very high heat flux. For the condensing surface, bundle heat transfer coefficients rarely exceeded 10 kW/m2-K, whereas values in excess of 30 kW/m2-K were sometimes seen for the evaporating surface.

Numerical Investigation of the Heat Transfer Characteristics of Liquid Lithium Metal in Spiral Tubes

Abstract The application of liquid lithium as a coolant for the forthcoming era of space nuclear reactors exhibits significant potential, and spiral tube heat exchanger components are commonly used in steam generators for reactors. However, the heat transfer characteristics of liquid lithium in spiral tubes are not yet fully understood. This research establishes a non-isothermal heat transfer model incorporating a modified turbulent Prandtl number to analyze the flow of liquid lithium through spiral tubes with varying geometries. Numerical analysis is carried out focusing on the influence of inlet velocity, the distribution of related parameters, and the geometry of spiral tubes. The results demonstrate that in the range of the dimensionless Dean number 8165–13,063, the Nusselt number and the pressure drop present approximately linear relations with the Dean number. For the distribution law of relevant physical quantities, the inner side of the tube displays an eye-anatomy low-flowrate area and a high-temperature area, while a low-pressure area forms on the inner pipe wall. Finally, the pitch and spiral radius are found to be reduced as much as possible to ensure high liquid lithium-based heat transfer performance with a small pressure drop. The optimized design parameters reveal that within the actual design range of non-dimensional pitch of 0.667–10.667 and curvature of 0.0556–0.1667, the non-dimensional pitch and curvature are 0.667–2.667 and 0.1667, respectively. This study offers valuable insights into the heat transfer properties of liquid lithium within heat exchangers of the spiral tube design, promoting its application in space nuclear reactor power supply.

Numerical investigation on characteristics of the onset of nucleate boiling in petal-shape fuel rod bundle assembly

The helical structure of the petal-shape fuel element results in a high heat transfer performance. Therefore, it is crucial to analyze its thermal–hydraulic characteristics. However, research on subcooled boiling in the petal-shape fuel rod bundle assembly is few. The characteristic of subcooled flow boiling in rod bundle assembly with a 2 × 2 petal-shape fuel rod was investigated numerically by Computational Fluid Dynamics. The results show that the wall superheat at the onset of nucleate boiling (ONB) decreases with the increasing mass flux and inlet subcooling degree, but has the opposite effect with pressure. The prediction accuracy of existing ONB correlations was investigated. The majority of correlations, however, deviate from the simulated values. Because they were not intended for the ONB of the petal-shape fuel rod, they did not account for the effects of enhanced heat transfer

Rational design process for gas turbine exhaust to supercritical CO2 waste heat recovery heat exchanger using topology optimization

Advances in additive manufacturing (AM) technologies and topology optimization methodologies are enabling sophisticated novel designs for heat exchanger performance. These tools have been demonstrated for development of high-performance heat sinks considering local or component-level performance factors (e.g., heat transfer per volume). To leverage such capabilities in larger-scale energy systems, structured design methodologies are needed that consider system-level factors, such as production cost, cycle-level efficiency, and operational constraints. This study seeks to develop and assess a rational approach for designing thermo-economically optimal heat exchangers for such applications. The methodology is illustrated through development of the Primary Heat Exchanger (PHX) for a supercritical carbon dioxide (sCO2) power cycle recovering exhaust heat from a 6 MW-scale natural gas turbine. The proposed approach begins with a detailed thermodynamic cycle model, which is then extended to account for techno-economics. Next, an optimal PHX heat transfer capacity target is identified, and a high-level geometry is selected based on operating characteristics. This geometry is then divided into repeating 2D prismatic unit cells, for which topology optimization is applied to identify high-performance heat transfer geometries. A key aspect of this process is that the unit cell geometries are optimized using the total PHX mass as the objective function, which represents a surrogate for production cost. This leads to distinct designs compared with approaches that optimize local heat transfer and flow resistance factors. A second topology-optimized design is developed using a representative local thermal-fluid performance objective function and is found to require 1.6× the mass of the design generated with the system-level techno-economic objective for the same unit cell size. Conventional-type PHX designs with simple longitudinally finned tubes are developed for comparison, and are found to require total masses 1.5× or greater than the design obtained with the proposed process. Integrating this approach with detailed additive manufacturing costing models and experimentally validated fabrication constraints can yield a streamlined workflow for HX design for future energy systems.

The Effect of Angled Fins in Generating Swirling Flows with Vortices That Augment Heat Transfer Performance in an Annular Conduit

This paper examined the usage of thermally conductive angled fins within an annular conduit through numerical simulation. Despite the thermally conductive nature of the fins increasing heat transfer surface area, this investigation found that using an optimal fin angle can promote the generation of vortical structures which aid heat transfer. Using ANSYS-Fluent with the SIMPLEC algorithm and the SST κ − ω turbulence model, this research found that heat transfer performance improved considerably when the generated vortices were sufficiently large and robust. However, the type of generated vortex had a profound impact when optimising for higher performance evaluation criterion (PEC) values. Longitudinal vortices improved heat transfer performance with a low impact on pressure drop increase, unlike transverse vortices, which increased pressure drop significantly. The fin angles of 50° and 60° yielded high heat transfer performance without much increase in pressure drop, thus resulting in higher PEC values. Additionally, using fin heights that correlate to 20% to 60% of the gap between the concentric walls was ideal when designing heat exchangers to achieve higher PEC values. The results of this numerical investigation have been validated both theoretically and experimentally to ensure accurate reporting of the findings.