Baffle Arrangements Research Articles

EXPLORING THE IMPACT OF GEOMETRIC PARAMETERS ON HEAT TRANSFER AND FLUID FLOW CHARACTERISTICS IN CROSS-TRIANGULAR GROOVED CHANNELS: A COMPUTATIONAL STUDY

In this study, the impact of geometric parameters of rectangular baffles with varying location angles and heights is investigated on the heat transfer and fluid flow characteristics of cross-triangular grooved channels. Computational methods are employed to explore these effects, utilizing the Ansys-Fluent program to solve the Navier-Stokes and energy equations, incorporating the k-ε turbulence model for numerical simulations. The inlet temperature of the air, serving as the working fluid, is set at 293 K, while the wall surface temperature of the lower triangular grooved channel remains fixed at 373 K. Rectangular baffles are tested with angles of 30°, 60°, and 90°, and heights of 0.25H, 0.5H, and 0.75H, respectively. The numerical results show good agreement with a 3.53% deviation compared to existing empirical data in the literature. The obtained findings are presented in terms of mean Nusselt (Num) number, fluid temperature, and Performance Evaluation Criterion (PEC) number variations taking into consideration of pressure drop for each rectangular baffle angle and height. Additionally, contour distributions of temperature and velocity are evaluated for different Reynolds numbers (Re) and arrangements of rectangular baffles. It has been determined that the Nu number value increases by 197.56% at a 90° angle and 0.75H height, compared to the 0.25H baffle height at Re=6000. Furthermore, at Re=1000, the PEC number is 84.50% higher with a baffle height of 0.25H and a baffle angle of 30° compared to the condition with a 90° angle.

Performance increasement in shell-and-tube heat exchangers reinforced with dimpled tubes: A correlation-based approach

Shell-and-tube heat exchangers (STHEs) are pivotal components in various industries, facilitating efficient heat transfer across fluid streams. The simulation of STHEs often demands a substantial number of computational cells, significantly when augmenting heat transfer surfaces by incorporating additional tubes or dimples. This study introduces a novel approach to mitigate the computational cost associated with STHE simulations. Correlations are designed to predict heat transfer within and outside the tubes, both in the presence and absence of dimples. These correlations are developed using the P-NTU thermal analysis method and a turbulence model that is carefully selected to align with the specific characteristics of STHEs. Following the validation of our approach, the correlations are applied to analyze the performance of various baffle arrangements within STHEs. Precisely, segmental, disk and donut baffle configurations, each featuring elliptical and teardrop dimples on the tube surfaces, are investigated. Furthermore, the impact of variations in shell and tube inlet mass flow rates on the overall performance of the heat exchanger is explored. The results reveal compelling findings. Elliptical dimples contribute to a remarkable enhancement in the performance evaluation criteria (PEC), yielding improvements of 36.7 % and 19.7 % for segmental as well as disk and donut baffle arrangements, respectively. Similarly, teardrop dimples exhibit their effectiveness, elevating the PEC by 51.5 % and 32.6 % in these same configurations under the specified working conditions. These findings contribute to the optimization of heat exchanger designs in diverse applications, fostering greater energy efficiency and environmental sustainability.

Finite element based computational analysis to study the effects of baffle and fin on the performance assessment of solar collector

The present work aims to develop an ideal solar collector layout through a finite element-based parametric study. The thermohydraulic performance factor of the solar collector was investigated with the placement of baffles and fins on the absorber plate. The cross-flow, channel, and twist designs of three alternative baffle/fin configurations were parametrised, and the heat transfer throughout the collector was analysed using COMSOL Multiphysics software. The parametrised design for cross-flow was the angle of solid baffle as 30°, 35° and 40°; whereas, for channel and twist design, the distance between the fins was varied at 50, 100 and 150 mm. The simulated result manifested that channel design had highest convective heat transfer coefficient of 21–27 W m−2 K−1, followed by cross-flow and twist design. Contrarily, twist and cross-flow design had lowest pressure drops of 0.6–1.27 Pa and 0.60–1.06 Pa, respectively, while channel design showed maximum pressure loss (35–467 Pa). The average overall thermal efficiency for cross-flow, channel, and twist design was 76.16 %, 74.26 %, and 70.65 %, respectively. The average thermohydraulic performance factor for cross flow and twist design was 11.25 % and 0.48 % higher, whereas 248.22 % lower for channel design compared to flat plate collector. The performance of the cross-flow 30 design was best out of all the designs in terms of the thermohydraulic performance factor, outlet temperature, pressure drop, and flow homogeneity inside the collector. Cross-flow 30 demonstrated a minimum friction factor of 0.004, comparable to a flat plate collector and had a double heat transfer coefficient.

Baffle structure effects on mass transfer and pressure drop of HT-PEMFC with orientated flow channels

Flow field design is critical to improving the overall performance of high-temperature proton exchange membrane fuel cells. Adding baffles in the flow channel has been proven to be effective in enhancing mass transfer. In this study, fuel cells with different baffle numbers, heights, and arrangements are numerically simulated to investigate the effects of reactant velocity, concentration distribution, and pressure drop on mass transfer and output performance. The results show that baffles are beneficial in improving cell performance, especially under high current density. With the increase in baffle number and height, the concentration of the reactant at the outlet decreases and the output power increases with the increase in pressure drop. The net power density growth rate is defined to characterize the cell performance. A lower pressure drop reduces the pumping power loss generated during reactant transfer, resulting in a staggered baffle structure with the highest net power density of 4329.65 W/m2. Compared with the traditional and parallel baffle channels, this value is improved by about 11.74% and 4.83%, respectively. Therefore, the optimized baffle channel can enhance the mass transfer, reduce the pumping power, and further improve the cell performance, providing an effective guide for the optimal design and development direction of the orientated flow channel.

RESEARCH OF TRIANGULAR BAFFLE PLACEMENT EFFECT ON THE HEAT TRANSFER AND FLOW FEATURES IN CROSS-CIRCULAR GROOVED TRIANGULAR CHANNELS

In this study, heat transfer performance and fluid flow properties for cross-circular grooved triangular ducts having different location angles and heights of the triangular baffles are studied numerically. The ANSYS Fluent program is applied to solve the equations of energy and the Navier-Stokes equations by employing the <i>k</i>-ε turbulence model in computational calculations. While the inlet temperature of the working fluid (air) is 293 K, the surface temperature of the lower circular grooved channels is taken constant at 373 K. Triangular baffles have different angles of 30°, 60°, and 90° and heights of 0.25H, 0.5H, and 0.75H. The range of the Reynolds number (Re) employed in this study is 1000-6000. Numerical results agreed with a 3.53% deviation according to empirical work that existed in the literature. The attained outcomes are presented as mean Nusselt number (Nu<sub>m</sub>), fluid temperature, turbulence kinetic energy, pressure, and performance evaluation criterion (PEC) variations for each triangular baffle angle and height. Contour distributions of the temperature, velocity, turbulence kinetic energy, and velocity vector are also evaluated for distinct Re numbers and triangular baffle arrangements. For Re = 3000, the Nu<sub>m</sub> number in the channel with a 90° baffle angle and 0.75H baffle height is 136.73% higher than that in the channel with 0.25H baffle height. In the channel with 0.25H baffle height, the PEC value is 91.91% higher in the 30° baffle angle condition than in the 90° one.

Estudo experimental acerca da influência do espaçamento na absorção Sonora de arranjos de baffles a base de PET

Abstract In rooms with unsatisfactoryauditory comfort, materials can be added to reduce the reflection of sound energy. These materials can be wools shaped in the form of panels, baffles or clouds, and the type of mounting in relation to the reflective surface greatly impacts their sound absorption performance. Therefore, the objective of this study is to verify the effect of row spacing in the sound absorption capacity of PET baffle arrangements. Sound absorption tests were performed in a reverberation room, testing PET wool baffles with a height of 50 cm and mounted in rows spaced 25 cm, 50 cm, 75 cm and 100 cm apart. The sound absorption results strongly correlate that the increase in row spacing in increments of 25 cm achieves considerable gains in sound absorption capacity of the baffles at each configuration starting from a spacing of 25 cm and up to 100 cm.

Thermal analysis and performance investigations of shell and tube heat exchanger using numerical simulations

The steam condenser is a crucial component in power plants, playing a vital role in influencing the overall performance of steam power plants. This paper delves into a detailed assessment of the thermal aspects and evaluation of steam surface condensers. To conduct this rigorous evaluation, we meticulously crafted a three-dimensional (3D) model of a multi-tube single-pass counter-flow heat exchanger using ANSYS Design-Modeller. Within this model, a multiphase mixture model was harnessed to replicate the condensation process that takes place within the condenser. After the model’s development, a series of computational fluid dynamics (CFD) simulations were expertly executed utilizing ANSYS Fluent Workbench. The simulations encompassed diverse cooling water flow rates and steam inlet velocities. Notably, two sets of CFD simulations were carried out: the initial set featured a velocity inlet in the condenser, while the second set involved CFD simulations with a pressure steam inlet. The findings derived from these simulations unveiled a noteworthy correlation between the condensation rate within the shell and both the rate of circulating water flow and the operational pressure of the condenser. Additionally, it was discerned that the condensation rate could be further influenced by the specific geometry of the condenser. In sum, this study concludes that optimizing the geometrical configuration and baffle arrangements holds promise for increasing the condensation rate and overall performance of steam condensers employed within steam power plants.

Effect of structure parameters on internal mass transfer and performance of PEMFC with spider-web flow field using multi-physical simulation

Optimizing the flow field structure is an important means to enhance gas transport and improve the proton exchange membrane fuel cell (PEMFC) performance. Based on the structural features of the spider-web, a three-dimensional multiphase flow model of the PEMFC with a spider-web biomimetic flow field (SWFF) was established firstly, and the influence of inlet and outlet positions on the performance of the PEMFC was investigated, then the cathode side catalytic layer (CL) oxygen utilization as an evaluation index based on the cluster model was proposed, which is used to investigate the effect of inlet and outlet positions on internal mass transfer and performance of PEMFC. Finally, the influence of different structural parameters on the performance of PEMFC with SWFF was investigated based on the orthogonal experimental design method. The results show that a reasonable arrangement of inlet and outlet positions can effectively increase the peak current density by 2.31% and reduce the pressure drop by 96.07% compared to a serpentine flow field. The placement of baffles at the intersection of the main channel and divergent channels can significantly improve the PEMFC performance. The results of the research provide a new evaluation index and a theoretical basis for the optimal design of flow field structures.

Experimental investigations on the thermal efficiency of a solar air collector with transverse rectangular baffles inclined by an angle of 135°

This work is experimental investigation on the impact of rectangular baffles on the thermo-hydraulic performance of a solar thermal collector. The study was conducted under moderate weather conditions and six cases were studied, including 2M135, 6M135, 10M135, 14M135, 18M135, and a smooth plate case. The results showed that the number and placement of baffles plays a crucial role in improving heat transfer and the best cases in terms of thermal performance were cases V and IV, with maximum values of h = 15.84 W/m2.k, and h = 17.46 W/m2k. The study also found that the heat transfer was greatest at the beginning of the channel and decreased towards the end. The highest thermal efficiency was recorded in case 18M135 with a maximum value of Ƞ=0.73.

Solidification analysis in an ice-on-coil ice storage system: Experimental and numerical approaches

Rapid economic growth has led to energy resources shortages, creating unique challenges for developing countries whose activities depend on energy. Thermal energy storage is an important field of technology that can be deployed as a reliable method to decrease net energy usage. For example, ice storage systems are one of the most efficient methods for saving cold energy. In this work, a combined experimental and numerical study has been carried out on the freezing process or solidification as charge mode in a novel ice-on-coil cold storage system with coil tube. Initial experimental results show that the initially designed evaporator, horizontal shell and coil tube heat exchanger (used to transfer cold energy between a mixture of water/ethylene glycol and refrigerant) failed to form uniform ice on the outer surface of the coil tube inside the ice tank. Also, the thickness of ice decreases from the top to the bottom of the coil, while trying to create a uniform thickness of ice around the coil is one of the main challenges in improving the performance of the proposed cold storage system. In the second part of this work, baffles are inserted inside the evaporator to create transverse fluid flows and to prevent shortcut flow, which leads to better heat transfer rates and, consequently, more uniform ice production around the coil tube. The results depict that although baffle placement demonstrates a slightly positive impact on improving the ice thickness along the coil, overall, it fails to eliminate the non-uniformity of ice production along the entire length of the coil tube. In the third section, a modified evaporator with four connected horizontal-placed coils is employed. According to the obtained results, it can be concluded that after 180 min, by employing the modified evaporator, ice thickness has increased by 14.71, 13.51, and 3.39 % in the bottom, middle, and top of the coil, respectively. It can be seen that utilizing the modified version of evaporator with four horizontal-placed coils leads to enhancement in the ice thickness specially at the bottom of the coil where the ice thickness is less than for the rest of the examined points, which was considered as one of the weaknesses of the primary system. Finally, in the last section, to realize better the solidification process around the coil tube inside the ice storage tank, the ice production process is modeled by performing three-dimensional simulations based on the finite volume method. The proposed model is then validated by using the experimental results.

RETRACTED: Performance and exergy analysis of an inclined solar still with baffle arrangements

This study presents the details of performance and exergy investigations on an inclined solar still with baffle arrangements. The shortage of consumable water creates the transformation of accessible brackish water into consumable water an unavoidable one and this can be accomplished utilizing sun-oriented refining. To remove drinkable water from pungent water, sun-oriented still is broadly utilized. To build the contact season of the pungent water with sunlight-based brilliance, perplex course of action is set to expand the opposition in the stream. This prompts more vanishing of brackish water. Therefore, the objective of this study is to improve freshwater yield. The experimental study is performed for two different mass flow rates (mf1 = 0.0833 kg/min and mf2 = 0.166 kg/min). An increase in the mass flow of water directly deteriorates the yield of fresh water. Highest accumulated freshwater yield is achieved as 2.908 kg/m2 day during the month of May for mf1 = 0.0833 kg/min. The accumulated freshwater yield improved by 4.23% in comparison with inclined solar still designs. Moreover, the yield is better by 3.49%–61.56% in comparison with various solar still designs. Using RSM, a polynomial statistical model is specified to estimate as well as maximize the freshwater yield of ISSB. The exergy analysis for mf1 = 0.0833 kg/min shows a maximum hourly exergy efficiency of 6.82%.

Multi-scale flume investigation of the influence of cylindrical baffles on the mobility of landslide debris

Debris flows travel downslope at high speed and often cause damage to the infrastructure of societies around the world. With increasing extreme rainfall events and urbanization in mountainous regions, effective structural countermeasures are in increasing demand. Over recent years, engineers have proposed the installation of an array of cylindrical columns, called baffles, to reduce the velocity of debris flows in catchments. However, existing design methods are highly empirical in nature, so it is unclear whether they are adequate or over designed, and appropriate specifications and arrangement of cylindrical baffles have still not been suggested. Moreover, previous experimental studies have predominantly modeled debris flows as dry granular flows at a laboratory scale. In this study, to investigate the effect of cylindrical baffles on the dynamic characteristics of debris flow, a series of small-scale flume tests was conducted using a flume equipped with devices to measure the flow interaction between baffles and the dynamic loads of debris flow. In addition, to investigate the scale effect of debris flows and cylindrical baffles on flow characteristics, large-scale tests were also performed according to different numbers of rows of baffles for similar baffle configurations confirmed by small-scale tests. Using the small- and large-scale test results, this study analyzed the energy dissipation and dynamic impact characteristics according to the height and number of rows of baffles. The analysis results showed that the use of baffles increased the energy dissipation of debris flows, and an additional row of baffles produced greater effects on the energy dissipation in the debris flows. Based on the test results, the average dynamic pressure coefficient for cylindrical baffles was 0.31.

NUMERICAL STUDY OF TURBULENT HEAT TRANSFER PROCESS IN DIFFERENT WAVY CHANNELS WITH SOLID AND PERFORATED BAFFLES

This study numerically investigated the effects of different baffle arrangements on heat transfer enhancement and flow in channels with different wave profiles. Four different wave profiles - rectangular, trapezoidal, triangular, and circular - were considered for the wavy channels. Analyses were made on the solid and perforated baffles that were installed vertically in the channel's central area to determine their hydrodynamic performance and convective heat transfer. Pressure-velocity coupling in discretized equations was handled with the SIMPLE algorithm, and analyses were carried out using the ANSYS Fluent solver. The standard <i>k-ε</i> turbulence model was used to solve the simulations. In this study, the channel geometry, the baffle arrangement, and the Reynolds number (4000 ≤ Re ≤ 12,000) were changed. The wavy surfaces were preserved at <i>T<sub>ω</sub></i> = 360 K. The results were presented with different dimensionless parameters such as Nusselt number (Nu), friction factor (<i>f</i>), and thermal performance factor (TPF). Analyses indicated that the Nu number increased with increasing Re in all channel flows. In all wave profiles, the highest heat transfer was obtained in the solid baffle arrangement. The heat transfer increased by 2.12 times in the rectangular channel with solid baffle at Re = 4000 compared to the channel without a baffle. The highest average Nusselt number and relative friction factor were obtained about 143.34 and 1.24, respectively, in rectangular profile with solid baffle at Re = 12,000. The variation of the friction factor differed according to the wave profile and the baffle arrangement. The triangular profile with two-perforation baffles had the lowest TPF value, 1.09, and the rectangle profile with a solid baffle had the highest TPF value, 2.02. The results of the present study showed that the flow and heat transfer behaviors were similar in trapezoidal and circular channels.

Thermal cooling of li-ion cylindrical cells battery module with baffles arrangement for airflow cooling numerical analysis

The demand for electric cars continues to grow every day due to their benefits, such as zero emissions, and the downsides of traditional internal combustion engines, such as toxic pollutants. There are some complications in the practical use of batteries, like thermal runaway and decreased battery life cycles and usage. Hence, this research introduced an innovative method to achieve uniform temperature distribution in the battery module and decrease the maximum temperature obtained in the battery cells. The new battery module has been designed by considering the cell holders at different cell heights. These cell holders are like a tray to hold the battery cells and act as fins, enhancing the uniform temperature distribution within the battery module. Base and new battery modules are analyzed at different discharge conditions with the same boundary conditions and physical parameters. The significance of cell holders acting as fins has been evaluated by analyzing the temperature contours and profiles for every cell of the battery module. The analysis of numerical results found that at 1, 2 and 3C rate, the maximum temperatures of 301.5, 303.9 and 308.8 K for base model and whereas for new model these are 300.6, 302.1, and 304 K, respectively. At 1C rate discharge, the temperature gradient among the cells (Tcell4-Tcell6) in the flow directions has been observed as 0.26 °C and 0.04 °C for the base and novel battery model, respectively.

Passive Control in Baffled Liquid storage Tank under Bi-directional Earthquakes

A comprehensive study of a 3D baffled concrete liquid storage tank (LST) is conducted to find out the maximum reduction in responses of the LSTs under a set of important parametric variations. They include (i) the type of earthquake; (ii) the optimum position and number of coupled baffles (top-mounted and bottom supported); and (iii) the angle of incidence earthquakes. Further, the percentage reductions of different responses of interest for the optimum baffled LST are investigated. The numerical study is performed in ABAQUS software for a square LST of 6m X 6m X 4.8m having a water height of 3.6m. The response quantities include the maximum mean values of base shear, overturning moment, top board displacement, hydrodynamic pressure, and sloshing height. The results of the study show that (i) with the optimum arrangement of baffles, significant reduction of in the sloshing height can be achieved; (ii) the type of earthquake does not have significant effect response reductions; and (iii) both PGA and angle of incidence of the earthquake have a moderate effect on response reductions.

Thermal-hydraulic analysis of Syltherm 800 thermal oil / γ-AlOOH nanofluid in a baffled shell and tube heat exchanger equipped with corrugated helical tube with two-phase approach

Present investigation studies two phase Syltherm 800 thermal oil / γ-AlOOH nanofluid flow and heat transfer in a baffled shell and tube heat exchanger equipped with corrugated helical tube numerically. Effects of using helical tube, corrugations, baffles and also their geometrical parameters are analyzed in thermal-hydraulic viewpoint. The governing equations are solved using finite volume method. The Eulerian-Eulerian single fluid two phase approach is used due to simulate the nanofluid flow. The code validation is done using valuable experimental and numerical references in literature and based on results there is a remarkable coincidence among the numerical results obtained from this work and the attained data of references in Nusselt number and pressure drop terms. According to obtained results, the configuration with 200 mm coil pitch, 70 mm coil diameter, Four-Obstacle arrangement, 20 mm obstacle diameter and novel baffle arrangement filled with nanofluid at 4% nanoparticle volume fraction (ϕ) and 30 nm nanoparticles diameter is suggested as the most efficient model among all configurations with performance evaluation criterion, (PEC)= 9.32, at Reynolds number of 54,000.

CFD modeling of ethylene degradation in gas-phase photocatalytic reactors.

Photocatalytic oxidation is a promising technology to degrade volatile organic compounds. The performance of photocatalytic reactors is affected by the hydrodynamics, radiation transfer, mass transfer and reaction kinetics. Baffles may improve the hydrodynamics. The effect of baffles on heterogeneous photocatalytic oxidation of gas-phase ethylene in three annular reactors is simulated using computational fluid dynamics. ANSYS Fluent is used to solve all governing equations. Baffles can improve the uniformity of flow and prolong the residence time. The residence time of the C-type reactor and B-type reactor is 0.5% greater than the unbaffled reactor. Baffles have little effect on the radiation distribution. The concentric arrangement of lamp and the reactor leads to a radial dominance of radiation. The effect of baffles on the diffusion of ethylene is complex. The effective diffusion coefficient at the catalyst surface in the C-type reactor decreases 9.5% and that in the B-type reactor increases 3% with respect to the unbaffled reactor. The outlet ethylene concentration is 4.19 ppmv for the U-type reactor, 3.93 ppmv for the C-type reactor and 3.62 ppmv for the B-type reactor. The optimal performance in the B-type reactor is due to the large diffusion coefficient of ethylene. The arrangement of baffles should enlarge the effective diffusion coefficient at the catalyst surface as far as possible.

A Numerical Study on the Effects of Perforated and Imperforate Baffles on the Sloshing Pressure of a Rectangular Tank

Sloshing has many industry applications, namely in offshore engineering, aerospace, ship building, and manufacturing. Sloshing simulation is essential to better understand the sloshing pattern and consequently to improve the tank design to reduce noise levels, stresses on the structure, and optimize the baffle configurations and arrangements. Thus, the aim of this study is to determine the effects of perforated (porous) and imperforate (solid) baffles on the sloshing pressure using ANSYS FLUENT software based on Volume of Fluid (VOF) method where a rectangular tank with 25% and 60% filling ratios was considered. In the first case, an unbaffled rectangular tank with 60% filling ratio was used for the validation purpose, while in the second case, a 25% filling ratio was investigated considering two scenarios, namely a unbaffled tank and a baffled tank case with perforated and imperforate baffles. The outcomes of the results indicate that perforated baffle can significantly reduce the sloshing pressure in the tank. The validation of the results also shows a good agreement with the published experimental results.

Numerical analysis of the return flow solar air heater (RF-SAH) with assimilation of V-type artificial roughness

A novel design of Return Flow Solar Air Heater (RFSAH) with different arrangements of baffles especially V-Type Artificial roughness is simulated and numerically analyzed with energy balance equations. To enhance the effectiveness of baffles, numerous studies have been conducted. The performance of the RFSAH is studied in terms of thermal efficiency, thermo-hydraulic efficiency, and optimization of baffle parameters. Maximum Thermal efficiency and thermo-hydraulic efficiency are found in RFSAH with baffle on both sides of the absorber plate and mass flow rate above 0.2kg/s. Sensitivity analysis of the influencing parameters is carried out and reported the best performance of the system on selective geometrical parameters (ψ=0.7, β=20%, e/H=1, p/e=0.8, α=60∘). The results obtained from the present model are validated with the published experimental results and have been found in quite reasonable agreement with an average error of 16.45%. Thermal and Thermohydraulic efficiency of RFSAH with a baffle on both sides of the absorber plate is maximum among baffles below, above, and on both sides of the absorber plate. It is observed that the thermal efficiency of RFSAH is greater than SF-SAH. The proposed optimum baffles roughness is suggested to increase the air upholding time period for more efficient output.

Study of Baffles Arrangement Influence on the Natural Convection into a Heated Square Channel

The present experimental paper is officiated to study the heat characteristics and performance of air flow through a square cross-sectional heated channel under natural heat convection conditions. The influence of baffles arrangement and perforated baffles on the rate of heat transfer through a channel are studied. Four cases of a heated channels are studied, one is a plain channel and other three channels with a baffle namely, three inline baffles, three staggered baffles and three staggered perforated baffles arrangements. The outer tested channels surfaces are electrically heated with a constant surface heat flux condition. All tested channels are fabricated by cold forming with constant dimensions using aluminum plate has thickness of 1.0 mm. The heat performance is assessed for all tested channels. The results of present paper are approved than the available data in the previous paper and a good convergence are noticed. Obtained experimental results appear that a three staggered perforated baffles arrangement is a best selection as it improves heat transfer rate in expression of Nusselt number, it higher about 22% to 27% than that the plain channel for same conditions.