Transfer Enhancement Research Articles

Partial magnetic field and segmental heating effects on hybrid nanofluidic convection in a tilted porous wavy cavity

The present study investigates the magneto-thermal convective process in an oriented porous wavy-walled geometry filled with Cu–Al2O3/water hybrid nanofluid, which is partially heated from the upper and lower walls under a partially active magnetic field. The sidewalls are cooled, while heating is carried out from the upper or lower walls or both. The flow-physics are greatly affected by the segmental heating and their positions, sidewall curvature, spatially active partial magnetic field, and all the flow-controlling variables. The transport equations are solved using the finite volume technique with SIMPLE and TDMA solver-based computing code. The hydro-thermal behavior of the thermal system is evaluated for several important variables, such as the Darcy-Rayleigh number, Hartmann number, Darcy number, concentration of hybrid nanofluid, partially active magnetic field strength, inclination and positions, geometry orientation, length of segmented heaters, and their position. It is revealed that the overall thermal transport phenomena can be precisely controlled by adjusting the position and dimension of segmented heaters, the active zone and direction of the imposed magnetizing field, and the cavity angle. Both the cavity angle and magnetic field angle of 90° enhance heat transfer. Top wall heating produces weak circulation. In the case of position study for segmental heating, the sidewall position is the best location for maximum heat transfer. The circulation strength and heat transfer are maximum for the bottom heated scenario, and the transfer enhancement goes up to 132.91%. In addition, an entropy generation analysis is conducted to understand the order of thermal, viscous, and magnetic effects on irreversibility production. The results demonstrate the effectiveness of the proposed approach in optimizing the system's performance.

Porous ionic polymers as a photocatalyst: Self-assembly of donor-acceptor by regulating the valence state of photo-responsive groups

The world is on high alert against trace but extremely hazardous pollution of heavy metals and organic dyes in wastewater. Among various treatments, porous photocatalyst with dual functions of adsorptive enrichment and photodegradation are highly desirable yet challenging. Herein, we demonstrate a robust donor-acceptor (D-A) self-assembly by regulating the valence state of photo-responsive groups to construct porous ionic. The density function theory calculations reveal that the excitons induced on the neutral pyridine group (D) can be attracted by its neighboring cationic pyridinium one (A), thus the distinct charges separation and transfer enhancement can be realized in one PIP-based photocatalyst. Guided by this, a partially ionized pyridine-pyridinium (PB-PIPs) photocatalysts are fabricated, which show excellent adsorption capacity for the heavy metal Cr(VI) anion on pyridinium cations and rhodamine B (RhB) on the pyridine rings. Significantly, the target-adsorptions promote the accurate deliveries of excitons, that the simultaneous photocatalytic reduction of Cr(VI) and oxidation of RhB are achieved. The photodegradation performance of PB-PIPs under visible-light irradiation is superior to the state-of-the-art organic photocatalysts. Therefore, this convenient strategy of the valence state regulation provides a promising solution to the focus of synergistically visible-light harvesting, charges separating and transferring, and target-delivering in photocatalysis.

Numerical Study on Thermal-Hydraulic Performance of Printed Circuit Heat Exchangers during Natural Gas Trans-Critical Liquefaction

Printed Circuit Heat Exchangers (PCHEs) are considered an excellent alternative for the main cryogenic heat exchanger of Floating Liquefied Natural Gas (FLNG) facilities due to their compact structure and strong heat transfer performance. However, it is unclear how to configure the geometry of the PCHE channels to achieve its optimal performance in the trans-critical liquefaction process of natural gas (NG), which is critical for the main heat exchanger. In this paper, we numerically studied the thermal-hydraulic characteristics of PCHEs with different channel types under the specified condition. The results elucidate that all channels have an enhancement of heat transfer near the pseudo-critical point of NG. All the wavy channels could improve the heat transfer performance of PCHEs, where the trapezoidal channel achieves the largest promotion. Compared with the straight channel, the local heat transfer coefficient could be increased by up to 53% in the trapezoidal channel. Additionally, vortex appeared at the bends of the wavy channels, which greatly increase the local friction loss. Among several channels, the total pressure drop of zigzag, fillet and the sinusoidal channel was almost the same, while that of the trapezoidal channel was the largest. Furthermore, we compared the comprehensive performance of different types of channels and found that the benefit of heat transfer enhancement could not offset the penalty of flow deterioration. Our work provides important guidance for the design of PCHEs employed in FLNG.

Modeling and Experimental Studies on Carbon Dioxide Absorption with Sodium Hydroxide Solution in a Rotating Zigzag Bed

The enhancement of mass transfer is very important in CO2 absorption, and a rotating zigzag bed (RZB) is a promising device to intensify the gas–liquid mass transfer efficiency. In this study, the mass transfer characteristics in an RZB in relation to the overall gas-phase volumetric mass-transfer coefficient (KGa) were investigated with a CO2–NaOH system. A mathematical model was established to illustrate the mechanism of the gas–liquid mass transfer with irreversible pseudo-first-order reaction in the RZB. The effects of various operating conditions on KGa were examined. Experimental results show that a rise in the liquid flow rate, inlet gas flow rate, rotational speed, absorbent temperature, and absorbent concentration was conducive to the mass transfer between gas and liquid in the RZB. It was found that the rotational speed had the largest impact on KGa in the RZB. The KGa predicted by the model agreed well with that by the experiments, with deviations generally within 10%. Therefore, this model can be employed to depict the mass transfer process between gas and liquid in an RZB and provide guidance for the application of RZBs in CO2 absorption.

Experimental Study of Ship Motion Effect on Pressurization and Holding Time of Tank Containers during Marine Transportation

Liquefied natural gas (LNG) is the cleanest fossil fuel available, producing less carbon emissions and fewer pollutants than other fossil fuels. Marine transportation is a key process in the LNG supply chain. The use of tank containers, which are portable equipment, can effectively facilitate multi-mode transportation. LNG evaporation causes pressurization, which is a safety concern during transportation. Ship motion and environmental temperature are the main factors affecting pressure variations. In this study, the effect of ship motion on pressurization and holding time was investigated through three types of experiments, namely, prototype, field, and self-pressurization experiments. The results showed that while increased boil-off gas was generated due to ship motion, this evaporation remained stable in dynamic cases. Higher evaporation rates were obtained under more severe dynamic conditions, and the holding time was shortened. The two different effects of ship motion on pressure development discussed here are the facilitation of pressurization due to the enhancement of heat transfer and the prevention of pressurization due to gas condensation at the vapor–liquid interface. These two effects show varied levels of predominance over the pressure variations depending on different stages of transportation. The holding time in the experiments was able to reach 87 days under the most severe condition, which is long enough for long-term shipping; the safety of transporting LNG in tank containers is further discussed based on the experimental results herein.

Enhancement of Heat Transfer in a Concentric Tube Counter Flow Heat Exchanger using CuO Nanofluids

Engineers and Scientists have always tried to increase the rate of heat transfer. The most commonly used base fluids do not provide a very high rate of heat transfer. This research work aims to investigate the enhancement of heat transfer rate in a concentric type (double pipe) counter flow heat exchanger using CuO nanofluids at different volume concentrations (0.01%, 0.05% and 0.1%). The experiments conducted on nanofluids showed that, at 0.1% volume concentration of nanofluid at 2.5 LPM, the heat transfer rate, Reynolds’s number and effectiveness were increased by 16.25%, 15.52% and 2.88% respectively compared to base fluid without nano-particles. Hence it was concluded that, CuO nanofluid is having a great potential to be used as a better heat transfer fluid in heat exchangers.

3D APT and NOE CEST-MRI of healthy volunteers and patients with non-enhancing glioma at 3\xa0T

ObjectiveClinical application of chemical exchange saturation transfer (CEST) can be performed with investigation of amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) effects. Here, we investigated APT- and NOE-weighted imaging based on advanced CEST metrics to map tumor heterogeneity of non-enhancing glioma at 3 T.Materials and methodsAPT- and NOE-weighted maps based on Lorentzian difference (LD) and inverse magnetization transfer ratio (MTRREX) were acquired with a 3D snapshot CEST acquisition at 3 T. Saturation power was investigated first by varying B1 (0.5–2 µT) in 5 healthy volunteers then by applying B1 of 0.5 and 1.5 µT in 10 patients with non-enhancing glioma. Tissue contrast (TC) and contrast-to-noise ratios (CNR) were calculated between glioma and normal appearing white matter (NAWM) and grey matter, in APT- and NOE-weighted images. Volume percentages of the tumor showing hypo/hyperintensity (VPhypo/hyper,CEST) in APT/NOE-weighted images were calculated for each patient.ResultsLD APT resulting from using a B1 of 1.5 µT was found to provide significant positive TCtumor,NAWM and MTRREX NOE (B1 of 1.5 µT) provided significant negative TCtumor,NAWM in tissue differentiation. MTRREX-based NOE imaging under 1.5 µT provided significantly larger VPhypo,CEST than MTRREX APT under 1.5 µT.ConclusionThis work showed that with a rapid CEST acquisition using a B1 saturation power of 1.5 µT and covering the whole tumor, analysis of both LD APT and MTRREX NOE allows for observing tumor heterogeneity, which will be beneficial in future studies using CEST-MRI to improve imaging diagnostics for non-enhancing glioma.

Numerical Evaluation for Spacer Vane Effects on Flow and Heat Transfer of Water at Supercritical Pressure in Annular Channel

ABSTRACT In the nuclear fuel structure, most spacers are constructed with vanes that increase turbulence flow mixing downstream of the spacer and therefore enhance the heat transfer rate. The objective of this work is numerical evaluation of the effects of a spacer without a vane and a spacer with a vane (hereinafter referred to as spacer/spacer with vane) on the flow and heat transfer of water at supercritical pressure downstream to the spacer of the annular channel. In this study, computational fluid dynamics (CFD) models of the annular channel have been developed considering spacer/spacer with vane. Experimental data for the heated annular channel have been used to validate the same CFD model (as the geometry used for the experiment) using the CFD code ANSYS Fluent. The CFD results show good agreement with the experimental data used, and hence, the developed CFD models of the annular channel that consider spacer/spacer with vane can be simulated with adequate precision for the flow and heat transfer downstream to the spacer. The effects of spacer/spacer with vane on heat transfer and flow behavior of water have been studied with numerical simulations for the following parameters: mass fluxes of 500 and 1000 kg/m2·s, heat flux of 400 kW/m2, pressure of 25 MPa, and inlet water temperature of 350°C. The results obtained through the simulations show that the spacer with vane has a remarkable influence on flow and heat transfer downstream to the spacer vane against spacer without a vane in an annular channel. Raising the flow velocity is an effective approach to reduce wall temperature and enhance the heat transfer in the channel. The range of the spacer effect in the enhancement of heat transfer is observed from X/D = 0 to 45 in the downstream direction. In addition, the simulation results for the Nusselt number ratio of the present CFD models have been compared with correlation data established by several researchers in a downstream direction to the spacer/spacer with vane, and qualitatively proper agreement has been found.

Numerical investigation of thermal radiation impact on gold–molybdenum disulfide/water hybrid nanofluids with convective condition

This analysis evaluates the characteristics of conventional nanofluid heat transfer with those of emerging hybrid nanofluid. Hybrid nanofluid, a new type of conventional fluid, has been used toward the enhancement of heat transfer in the boundary layer flow. This research also prompts that 0.001 solid volume fraction of Gold (Au) is fixed, then consequently, various solid volume fractions of Molybdenum disulfide (Mo) are added into the mixture with water as the base fluid to form Au - Mo/water hybrid nanofluid. Using the necessary similarity variables, the governing non-linear partial differential equations are resolved into a system of coupled ordinary non-linear differential equations. The transformed equations are numerically solved by employing the Runge-Kutta Fehlberg method with shooting technique. The numerical parametric analysis, which has been conducted to explore the effects of different physical parameters involved in the problem, provides comparisons. The present problem is new, original, with many substantial findings in the current industry for practical problems. It is found that dual solutions exist up to a certain value of the decreases as nanoparticle volume fractions for Molybdenum disulfide increase.

Effect of Nanofluids on the Enhancement of Boiling Heat Transfer: A Review

Boiling heat transfer can play a vital role in the two-phase flow applications. The analysis of the boiling hat transfer enhancement is of importance in such applications and the enhancement can be mostly conducted by using various active and passive techniques. One type of passive techniques is the enhancement of heat transfer by nanofluids. This article presents an extensive review on the effect of different nanofluids on the enhancement of heat transfer coefficient (HTC) and critical heat flux (CHF) for both pool as well as flow boiling. Nanoparticles addition to a working fluid is done arbitrarily to improve the thermophysical properties which in turn improves heat transfer rate. Numerous works have been done in the studies on nanofluid boiling. Among various nanoparticles, the most frequently used nanoparticles are Al2O3 and TiO2. In the case of binary nanoparticles, the most commonly used combination is Al2O3 and TiO2. After reviewing the relevant literatures, it is found that for pool boiling, the maximum HTC is increased to 138% for TiO2 nanoparticles and the maximum CHF is increased to 274.2% for MWCNTs. Conversely, in flow boiling the maximum HTC is increased to 126% for ZnO nanoparticles and the maximum CHF increased to as 100% for GO nanoparticles. In addition, when two or more nanoparticles in succession or binary nanofluids are used the CHF in pool boiling increased up to 100% for Al2O3 and TiO2 as well as the CHF in flow boiling increased up to 100% for Al2O3, ZnO, and Diamond. Though the information of the coefficient of heat transfer and the critical heat flux varied for different nanofluids and vary from experiment to experiment for each of the nanofluids. This variation happens because the coefficient of heat transfer and the critical heat flux in boiling is dependent upon several factors.

An Investigation of Heat Transfer and Pressure Drop Enhancement of Various Perforated Circular Finned Tubes at Different Tube Tilt Angles

The thermal and flow performance of the circular annular finned tube heat exchanger with perforated fins were investigated numerically using ANSYS Fluent 2020 software, RNG k-e model with enhanced wall treatment, global performance criterion was introduced as evaluation factor of the heat exchanger performance, the parameters to be investigated were the number of holes, size of hole, tilt angle of the finned tube, fin height and spacing between fins. Agreement was found with literature that the tilt angle causes increase in heat transfer rate and increase in the pressure drop as well, but the change the global performance criterion as function to tilt angle depends on the fin heights, for higher fin heights the effective change of the pressure drop become greater than the increase in the heat transfer rate and the contrast occur in the cases of smaller fin heights, we have found that the perforation in tilted annular circular finned tubes causes an increase in the heat transfer rate and an enhancement in the total heat exchanger performance, increasing the number of holes will enhance the performance of the heat exchanger and the spacing increase reduces the heat exchanger performance.

Toward applications of near-field radiative heat transfer with micro-hotplates

Bringing bodies close together at sub-micron distances can drastically enhance radiative heat transfer, leading to heat fluxes greater than the blackbody limit set by Stefan–Boltzmann law. This effect, known as near-field radiative heat transfer (NFRHT), has wide implications for thermal management in microsystems, as well as technological applications such as direct heat to electricity conversion in thermophotovoltaic cells. Here, we demonstrate NFRHT from microfabricated hotplates made by surface micromachining of hbox {SiO}_2/hbox {SiN} thin films deposited on a sacrificial amorphous Si layer. The sacrificial layer is dry etched to form wide membranes ({100},upmu hbox {m} times {100},upmu hbox {m}) separated from the substrate by nanometric distances. Nickel traces allow both resistive heating and temperature measurement on the micro-hotplates. We report on two samples with measured gaps of {610},hbox {nm} and {280},hbox {nm}. The membranes can be heated up to {250},^{circ }hbox {C} under vacuum with no mechanical damage. At {120},^{circ }hbox {C} we observed a 6.4-fold enhancement of radiative heat transfer compared to far-field emission for the smallest gap and a 3.5-fold enhancement for the larger gap. Furthermore, the measured transmitted power exhibits an exponential dependence with respect to gap size, a clear signature of NFRHT. Calculations of photon transmission probabilities indicate that the observed increase in heat transfer can be attributed to near-field coupling by surface phonon-polaritons supported by the hbox {SiO}_2 films. The fabrication process presented here, relying solely on well-established surface micromachining technology, is a key step toward integration of NFRHT in industrial applications.

Analysis of Tube in Tube Heat Exchanger Fitted with Twisted Tape with Square Cut

Numerical investigations of heat transfer and friction factor characteristics in swirling flow conditions using CFD simulation. A commercial CFD package, Ansys R1 2021, was used in this study. 3D models for circular tube fitted with Square-cut twisted tape (QCT) inserts with two pitch 100mm, 50 mm and different cut depths (d = 4 mm, 5mm and 7 mm) were generated for the simulation. Insertion of twisted tapes into the tubes of the heat exchangers is important for enhancement of heat transfer to increase the performance of heat exchangers. In the present Research work, computational analysis has been carried out to analyse the enhancement of rate of heat transfer using Square cut cross sectional twisted tape inserts in a pipe heat exchanger. Geometrical model of heat exchanger has been generated and computational mesh is created using ICEM CFD, an advanced meshing software. The analysis has been carried out for plain tube and with Square cut cross sectional twisted tape inserts with different twist ratio analyse the temperature distribution, velocity distribution and pressure distribution along the tubes and shell using ICEM CFD.

Performance analysis of a novel thermal transpiration vacuum cooling system

ABSTRACT A novel vacuum cooling system, which mainly consists of a 49-stage thermal transpiration based vacuum pump and a 100 L vacuum vessel, is proposed. The novel system can directly be driven by heat, while its structure and operation are similar to those of traditional mechanical vacuum systems. Then, a mathematic model is established to predict the performance of the novel system. The cooling capacity and coefficient of performance of the novel system increase with the rises of both parameters related to vacuum pump (the temperature difference between cold and hot chamber and pressure difference coefficient) and parameters related to vacuum vessel (mass transfer coefficient, chilled water temperature and supplement water temperature). It is a feasible way to raise system performance by cooling cold chambers, while heating hot chambers except for enhancement of mass transfer. The novel vacuum cooling system can produce relatively large cooling capacity exceeding 10,000 W at chilled water temperature over 289 K, the coefficient of performance (ranges from 0.71 to 1.48) of which is still comparable to that of the existing absorption refrigeration. It is clear that the novel thermal transpiration vacuum cooling is competitive among lots of emerging refrigeration technologies.

Enhancement of condensation heat transfer at aluminum surfaces via laser-induced surface roughening

Enhancement of condensation heat transfer at aluminum surfaces via laser-induced surface roughening

Bio-inspired evaporation from shaped interfaces: an experimental study

Evaporative interfaces help process heat and substances in a variety of technical realms, from electronic to architectural applications. Because geometry affects the hydraulics, thermal properties and aerodynamics of evaporative devices, their performance can be tuned through design. While non-smooth interfaces are widely exploited to enhance transfer passively, surface area extension in packed volumes is a predominant line of research. This leaves aerodynamic structure-transfer relations and the impact of geometry itself unclear. Meanwhile, protrusions in leaves such as lobes and toothed margins have been associated with enhanced vapor dissipation. This experimental study explores the design space of leaf-inspired structures with evaporating protrusions. Three sets of water-absorbing models with fixed evaporating surface area and unlimited hydraulic supply were tested: (1) paper strips with dimension-equivalent protrusions of varied shape and degree of elongation; (2) cellulose sponges with the same designs as their cross-sectional profile, extruded three-dimensionally; (3) ceramic tiles with grooves of varied cross-section, conceived as building elements for evaporative cooling. Overall, results demonstrate that protrusions affect mass transfer rate and surface temperatures and can be integrated in the design of evaporative exchangers with non-smooth geometries. For the paper models, evaporation rate correlated with protrusion aspect ratio, supporting a functional interpretation of leaf design and its utilization in low-wind plate-fin exchangers. However, the same transfer enhancement was not regained from simply extruding an effective design into three-dimensions. For the ceramic tiles, geometry-driven differences in evaporation depended on the aerodynamic roughness and size of the grooved pattern, and on ventilation. Their outdoor thermal behavior was complex due to a multifaceted interaction with the environment and geometry-related factors such as self-shading and thermal mass. Ultimately, this design effort illustrates the potential of structured interfaces for evaporative exchange and thermoregulating the built environment.

연성체를 이용한 열전달 향상 시스템 수치해석

열전달은 다양한 산업에서 시스템 설계 시 반드시 고려해야만 하는 중요한 분야이며, 많은 연구자들이 열전달을 향상시키기 위해 다양한 형태의 와류 생성기를 도입하였다. 강체 와류 생성기의 경우 높은 압력 강하로 인해 에너지 손실이 크게 발생하여 최근에는 연성의 성질을 갖는 와류 생성기를 이용하여 열전달 향상을 도모하는 연구들이 활발히 진행되고 있다. 본 연구에서는 채널 중심축에 대해 비대칭적으로 기울어진 연성 와류 생성기를 이용한 열전달 향상 시스템을 수치적으로 분석하였으며, 유체-연성체-열 상호작용을 고려하기 위해 가상경계기법을 사용하였다. 와류 생성기의 굽힘 계수가 일정할 때, 기울어짐 각도가 증가할수록 와류 생성기의 펄럭임 현상이 크게 나타났으며, 펄럭임 운동에 의해 와류 구조가 생성되어 열전달이 증가되었다. 기울어짐 각도가 1/4 π 및 3/4 π일 때, 열전달 값은 각각 2%, 116%증가함을 확인하였다.

Diffusion and reaction in pore hierarchies by the two-region model

The two-region (“Kärger”) model of diffusion in complex pore spaces is exploited for quantitating mass transfer in hierarchically organized nanoporous materials, consisting of a continuous microporous bulk phase permeated by a network of transport pores. With the implications that the diffusivity in the transport pores significantly exceeds the diffusivity in the micropores and that the relative population of the transport pores is far below that of the micropores, overall transport depends on only three independent parameters. Depending on their interrelation, enhancement of the overall mass transfer is found to be ensured by two fundamentally different mechanisms. They are referred to as the limiting cases of fast and slow exchange, with the respective time constants of molecular uptake being controlled by different parameters. Complemented with reaction terms, the two-region model may equally successfully be applied to the quantitation of the combined effect of diffusion and reaction in terms of the effectiveness factor. Generalization of the classical Thiele concept is shown to provide an excellent estimate of the effectiveness factor of a chemical reaction in hierarchically porous materials, solely based on the intrinsic reaction rate and the time constant of molecular uptake relevant to the given conditions.

Comparing single-phase thermal hydraulic performance of a right and left turn twisted tape insert in a tube

Single-phase heat transfer and pressure drop tests were conducted in a tube with two types of twisted tapes. Each tape had exactly similar physical parameters and were made of the same material except that each had an opposite twist that resulted in a clockwise and anticlockwise flow swirl, i.e., left turn and right turn, respectively. Each type had twist ratio of 4 and 5.5 on a 180° twist. The tapes were tested in a tube-in-tube heat exchanger having 2 m length. The internal tube of the heat exchanger had 19.05 mm outer diameter and 1.65 mm wall thickness. Fresh water and 30% water/glycol solution were used as cold and hot fluids. Experiments were performed with Reynolds number varying between 2500 and 11,500 at Prandtl numbers of 9 and 14. Heat transfer and pressure drop enhancement was observed compared to plain tube at all operating conditions with 6–7% higher thermal performance with tighter twist tape. The Left Turn tape with a twist ratio of 5.5 showed slightly better thermal performance beyond Re > 8000 and with a twist ratio of 4 beyond Re > 4000. Similar trends were observed for the pressure drop. This is the first time a study on the subject was initiated assuming that the earth’s rotational effect “could” play a role in the flow swirl pattern inside a conduit. It is recommended to carry out intensive work on the subject with different tape twist ratios, fluids and more importantly larger conduits. The information generated could be of interest to the Concentrated Solar Power industry that uses high-temperature thermal oils. Any improvement in performance could result in lowering the operational cost, and therefore suitable type of twisted tapes could be used for upper and lower hemispheres.

Review on Heat Transfer Enhancement by Louvered Fin

The heat transfer enhancement is recycled in many engineering uses such as heat exchangers, refrigeration and air conditioning structures, chemical apparatuses, and automobile radiators. Hence many enhancing extended fin patterns are developed and used. In multi louvered fin, in this segment for multi-row fin and tube heat exchanger, an increase in heat transfer enhancement is found 58% for ReH = 350. When the Reynolds number is 1075, the temperature gradient is more distinct for greater louver angle that is the higher heat transfer enhanced for large louver angle. For variable louver angle heat exchanger, the maximum heat transfer improvement achieved by 118% Reynolds number at 1075. In the vortex generator for the delta winglet vortex generator, the extreme enhancement of heat transfer increased to 16% compared to the baseline geometry (at ReDh = 600). For a compact louvered heat exchanger, the results showed that a regular arrangement of louvered fins gives a 9.3% heat transfer improvement. In multi-region louver fins and flat tubes heat exchanger, the louver fin with 4 regions and the louver fin with 6 regions are far better than the conventional fin in overall performance. At the same time, the louver fin with 6 regions is also better than the louver fin with 4-region. The available work is in experimental form as well as numerical form performed by computational fluid dynamics.