Jun Du^1,*, Xin Wu¹, Ruonan Li¹, Ranran Cheng¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 77-87, 2019, DOI:10.32604/fdmp.2019.05949

Abstract In this paper, we take the mid-temperature gravity heat pipe exchanger as the research object, simulate the fluid flow field, temperature field and the working state of heat pipe in the heat exchanger by Fluent software. The effects of different operating parameters and fin parameters on the heat transfer performance of heat exchangers are studied. The results show that the heat transfer performance of the mid-temperature gravity heat pipe exchanger is the best when the fin spacing is between 5 mm and 6 mm, the height of the heat pipe is between 12 mm and More >

AlemKarima^a,*, Sahel Djamel^b , Nemdili Ali^c, Ameur Houari^d

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-7, 2018, DOI:10.5098/hmt.10.27

Abstract In the present paper, the effects of a new baffle design on the efficiency of a tubular heat exchanger are numerically investigated. It concerns butterfly baffles inserted in a cylindrical tube heat exchanger. We focus on the influence of the shape of baffles, the space between baffles (pitch ratio, PR) and the baffle size (i.e. the blockage ratio, BR) on the heat transfer and flow characteristics. Three geometrical configurations with different PRs are realized (PR = 1, 2 and 4) and five others with different blockage ratios (BR = 0.1, 0.2, 0.3, 0.4 and 0.5). More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-19, 2018, DOI:10.5098/hmt.10.6

Abstract Convective heat transfer, pressure loss and thermal performance in a heat exchanger tube inserted with the modified V-shaped baffle are investigated numerically. The influences of the flow attack angle (α = 20o , 30o and 45o ), baffle height in term of blockage ratio (b/D = BR = 0.05, 0.10, 0.15, 0.20 and 0.25) and arrangement (The V-tip pointing downstream is called “V-Downstream”, while the V-tip pointing upstream is named “V-Upstream”.) on heat transfer and friction loss are presented for the Reynolds number in range 100 – 1200 (laminar region). The numerical study (finite volume… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-16, 2018, DOI:10.5098/hmt.11.29

Abstract Numerical predictions on flow and heat transfer in a square channel heat exchanger placed with V-baffle are examined. The gap spacing between the V-baffle and channel wall is varied for all baffle heights. The laminar regime with Re = 100 – 1000 is considered. The numerical model for the square channel heat exchanger placed with V-baffle is validated. The preliminary result reveals that the computational domain has reliability to predict flow and heat transfer in the channel. The mechanisms on flow and heat transfer in the heat exchanger channel are illustrated at the numerical result… More >

Xiang Zhang, Hadi Keramati, Martinus Arie, Farah Singer, Ratnesh Tiwari, Amir Shooshtari, Michael Ohadi^*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-14, 2018, DOI:10.5098/hmt.11.18

Abstract Heat exchangers are key components of most power conversion systems, a few industrial sectors can particularly benefit from high temperature heat exchangers. Examples include conventional aerospace applications, advanced nuclear power generation systems, and high efficiency stationary and mobile modular fossil fuel to shaft power/electricity conversion systems. This paper provides a review of high temperature heat exchangers in terms of build materials, general design, manufacturing techniques, and operating parameters for the selected applications. Challenges associated with conventional and advanced fabrication technologies of high temperature heat exchangers are discussed. Finally, the paper outlines future research needs of More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-14, 2018, DOI:10.5098/hmt.11.10

Abstract Numerical analysis on flow configuration, heat transfer behavior and thermal performance in the heat exchanger tube equipped with various flow attack angles of the inclined wavy surface are presented. The laminar flow (Re = 100 – 1200) and turbulent flow (Re = 3000 – 10000) are considered for the present investigation. The flow attack angles of the inclined wavy surface are varied as 15o – 60o . The finite volume method with SIMPLE algorithm is selected to evaluate the current problem. The numerical results are reported in terms of flow and heat transfer mechanisms. The More >

V. Venkatachalam^{1, *}, D. Prabhakaran¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.3, pp. 321-334, 2018, DOI:10.3970/cmes.2018.114.321

Abstract This paper presents, using Lyapunov-Krasovskii functional technique combined with reciprocal convex lemma is considered for a networked control temperature control system with additive time-varying-delays. In the stability analysis, a new LK functional is assumed, and take the time-derivative of the (LK) functional, using reciprocal convex combination technique was employed to obtain less conservative stability criteria. Finally, the proposed stability analysis culminates into a stability criterion in the LMI (linear matrix inequalities) framework. The results obtained are in accordance with the theoretically obtained in the temperature control system and they are closer to the standard benchmark More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-8, 2017, DOI:10.5098/hmt.8.35

Abstract Numerical investigations on flow and heat transfer characteristics in a circular tube heat exchanger inserted with right triangular wavy surfaces are reported. The configurations of the wavy surfaces; incline and V-shape, are studied with flow attack angles of 30o, 45o and 60o for the Reynolds numbers, Re = 100 – 2000. The numerical results are compared with the smooth circular tube. The mechanisms on flow and heat transfer in the tube heat exchanger with the wavy surface are presented. As the results, the wavy surface can generate the vortex flow and impinging flow through the test… More >

Stephen K. Ogbonnaya, Oluseyi O. Ajayi^*

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-12, 2017, DOI:10.5098/hmt.9.31

Abstract Heat exchangers as a heat transfer device has gained wide applications across different levels of domestic and industrial set-ups. Various studies have been carried out to study, analyse and predict its performance. However, one major phenomenon that limits heat exchanger performance is attributed to fouling. Based on this, various studies and approaches have focused on reduction, elimination and mitigation of fouling. This study therefore focused on this. It reviewed several attempts that have been carried out to understand and mitigate the incidents of fouling in heat exchangers. The study found that despite the existing models More >

Divyprakash C. Pal, Abhik Majumder^*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-9, 2016, DOI:10.5098/hmt.7.1

Abstract In this present work heat transfer characteristics, thermal performance and pressure drop are studied numerically for a finned-tube bank heat exchanger with Delta Winglet Vortex Generator (DWVG) on the fin at different angle of attack (α). The thermo-fluid is studied by varying α at 15o , 25o , 30o and 35o . The base length (lDW) of the winglet also varied from 20mm to 35mm. The heat transfer coefficient and pressure drop increased in all the cases with increase in Reynolds number. However, significant increase in heat transfer of about 23.92% was observed for α More >