scholarly journals Heat Transfer Correlations for Star-Shaped Fins

2021 ◽  
Vol 11 (13) ◽  
pp. 5912
Author(s):  
Mladen Bošnjaković ◽  
Ante Čikić ◽  
Simon Muhič ◽  
Mario Holik
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Laboratory Tests ◽  
Correlation Coefficients ◽  
Test Results ◽  
Air Velocity ◽  
Staggered Arrangement ◽  
Fin Thickness

Star-shaped fins are a newer type of fin for which correlations for heat transfer and pressure drop do not yet exist in the literature. Therefore, correlation equations for air-side heat transfer and pressure drop in a finned heat exchanger with star-shaped stainless-steel fins in staggered arrangement were developed in this work. To obtain these correlations, a numerical analysis of the basic heat exchanger geometry and another 21 variants of heat exchanger geometry was performed using computational fluid dynamics, and then the results of laboratory tests of a model of heat exchangers with star-shaped fins were used. In the numerical analysis, the fin pitch, the fin thickness, and the air velocity at the inlet to the heat exchanger were varied. The Nusselt (Nu) and Euler (Eu) numbers were determined for each variation analyzed. Initial correlations for Nu and Eu were derived using the least-squares deviation method. The correlation coefficients thus obtained were adjusted to agree with the results of the laboratory tests. The deviation of the final obtained correlation for Nu from the experimental test results was up to 10% in the range of Re < 3500, whereas for higher values of Re, the deviation was less than 2%. The Eu correlation deviated from experimental results up to 19% in the range of Re < 4000, whereas in the range of Re > 5600, the deviation was less than 1%. The correlations were valid in the range 2000 < Re < 16,000.

scholarly journals Parametric study on heat transfer characteristics of waste heat recovery heat exchanger for automotive exhaust thermoelectric generator

2018 ◽  
Vol 7 (3.3) ◽  
pp. 6
Author(s):  
Ki. Hyun Kim ◽  
Mahesh Suresh Patil ◽  
Jae Hyeong Seo ◽  
Chan Jung Kim ◽  
Gee Soo Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Background/Objectives: The parametric study on heat transfer characteristics of waste heat recovery heat exchanger was carried out by varying different geometry parameters to suggest optimum model for automotive exhaust thermoelectric generator.Methods/Statistical analysis: The numerical analysis method was applied to compare the heat transfer characteristics of various heat exchanger models. For numerical analysis, various models were created using computer aided drawing considering different fin arrangements and guide plates. Commercial code ANSYS 17.0 was used to analyze the heat transfer and fluid flow behavior of various models. Mesh independency was conducted to enhance the accuracy of the results.Findings: The thermal performance analysis of waste heat recovery heat exchanger was conducted considering pressure drop and heat flux at cooling side. As the fin spaces were increased, the heat flux at cooling side increased, but pressure drop also increased.Improvements/Applications: The developed geometry can be further optimized considering other geometry parameters and efficient system could be developed for power generation using waste heat with heat recovery exchanger and the present study provides detailed numerical analysis considering pressure drop and heat flux. 

Study on the Air-Side Heat Transfer and Pressure Drop for Fin-Tube Heat Exchangers

2002 ◽  
Author(s):  
Ji Hwan Jeong ◽  
Keun Sun Chang ◽  
Young Chel Kweon ◽  
Sang Jae Lee ◽  
Min Kyu Lee
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Unit Area ◽  
Numerical Results ◽  
Experimental Measurements ◽  
Air Velocity ◽  
Fin Tube ◽  
Good Agreement

Experimental measurements and numerical analysis have been carried out in order to investigate performances of air-side heat transfer and pressure drop for six types of heat exhcangers with various fin shapes. An air-enthalpy calorimeter is used in this work. Numerical analysis shows a good agreement with experimental measurements. Measurements for six types of heat exchangers at various air-velocity are compared with each other. Heat transfer per unit area appears to be nearly the same in the range of 0.7~0.9 m/s while it varies within 3% at 1.5 m/s. The numerical results show that most of heat transfer takes place through fins for all types and majority of heat transfer happens from the 1st row.

Numerical analysis for heat transfer and pressure drop characteristics of "Shell-tube" heat exchanger with various baffle factor

2014 ◽  
Vol 38 (4) ◽  
pp. 367-375 ◽  
Author(s):  
Rong-Rong Hou ◽  
Hyeong-Seon Park ◽  
Jun-Kyu Yoon ◽  
Jong-Han Lim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Tube Heat Exchanger

Experimental Investigation of Flat Tube-Louver Fin Heat Exchanger Performance Working as a Cooler in Dry and Wet Conditions

2012 ◽  
Author(s):  
Sahil Popli ◽  
Yunho Hwang ◽  
Reinhard Radermacher
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Water Flow Rate ◽  
Ambient Air ◽  
Water Cooling ◽  
Air Velocity ◽  
Flat Tube ◽  
Side Pressure ◽  
Dry And Wet Conditions

An experimental study has been conducted to evaluate the performance of a flat-tube louver-fin heat exchanger working as a cooler, with frontal area of 0.25 m2 in both dry and wet conditions. Deluge water cooling at different flow rates was achieved by incorporating perforated tube-type distributor on top of the heat exchanger. Water at 35°C temperature was used as heat transfer fluid at cooler inlet. Ambient air and deluge cooling water were both maintained at 22°C temperature. Heat exchanger capacity and air-side pressure drop were measured with the heat exchanger angle set at 0° and 21° from vertical, with a frontal air velocity of 1.4 m/s and 3.5 m/s without deluge water cooling, and a frontal air velocity of 1.2 m/s, 1.4 m/s with deluge water cooling. Significant capacity enhancement could be obtained both with the use of deluge water cooling and with the heat exchanger angle set at 21° from vertical. Furthermore, it was found that approximately same capacity was obtained at both 0° and 21° angle when wetting water flow rate was reduced from 0.17 kg/s to 0.063 kg/s, without significant reduction in air-side pressure drop. This study highlights the importance of wetting of heat transfer surfaces of compact flat tube heat exchangers and provides motivation for further research in this area.

SIMULATION RESULTS FOR THE EFFECT OF FIN GEOMETRY ON THE PERFORMANCE OF A CONCENTRIC HEAT EXCHANGER

2014 ◽  
Vol 22 (04) ◽  
pp. 1450026 ◽  
Author(s):  
HONGGI CHO ◽  
TAEHUN KIM ◽  
JUNGHO KIM ◽  
CHANGSEON LEE ◽  
JAEYOUNG CHOI
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Working Fluid ◽  
Outer Diameter ◽  
Maximum Heat ◽  
Simulation Results ◽  
Fin Thickness

The present study is aimed to investigate the effect of fin geometry on the performance of a concentric heat exchanger with the commercial CFD software of Star CCM+. In general, the concentric heat exchanger consists of inner and outer tubes. The inner tube has a lot of serrated fins spirally manufactured on its surface in order to increase the heat transfer performance. A simplified simulation model has been applied to simulate the performance of the concentric heat exchanger in this study. Both inner and outer tubes have the same length of 60 mm. The inner diameter of outer tube is 17.05 mm. The outer diameter of inner tube before manufacturing fins is 11.5 mm. Water is used as a working fluid and the concentric heat exchanger has a counter-flow configuration. The simulation parameters were fin height, fin thickness and fin width. It was found that heat transfer rate increased by 3–4% as the fin height increased from 0.95 to 1.15 mm. However, pressure drop increased highly by 39–41%. The effectiveness, which could be evaluated by calculating the ratio of enhancement of heat transfer rate to that of pressure drop, was about 74% for the fin height of 1.15 mm. In case of fin height of 1.05 mm, the effectiveness was 88% due to the increase in pressure drop, about 15%, compared with the base fin height of 0.95 mm. Also, it was noted that the effectiveness was about 88% and 95% for the fin thickness of 0.5 and 0.4 mm, respectively, compared with the base fin thickness of 0.3 mm. In case of increasing the fin width from 0.8 to 1.2 mm, the heat transfer rates slightly increased by 1–2% and the pressures drops increased by 3–4%. Hence, the effectiveness was about 98% for the fin width of 1.2 mm. And the effectiveness for the fin width of 1.0 mm was 97%. Based on the simulation results, it was concluded that maximum heat transfer rate has been obtained when the fin height is 1.15 mm. However, pressure drop is considerably increased by 39–41%. Therefore, the fin height should be carefully determined according to the criteria of pressure drop.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

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