Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-16, 2016, DOI:10.5098/hmt.7.22

Abstract The numerical investigations on flow structure, heat transfer characteristic and thermal performance in a circular tube heat exchanger with various shapes of winglet vortex generators are reported. The rectangular winglet vortex generators (RWVG), delta winglet vortex generators (DWVG) and curve winglet vortex generators (CWVG) are inserted in the middle of the test tube on both downstream and upstream arrangements. The effects of blockage ratios; BR = 0.1 – 0.3, with single pitch ratio (PR = 1) and flow attack angle (α = 30o) on thermal performance are studied for the Reynolds numbers; Re = 100 – 2000. The numerical results… 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 at 35o when compared with… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-16, 2021, DOI:10.5098/hmt.16.17

Abstract This research reports numerical examinations on fluid flow, heat transfer behavior and thermal performance analysis in a circular tube equipped with modified V-baffles (CTMVB). The modified V-baffle (MVB) is a combination vortex generator between V-baffles/V-orifices which are placed on the tube wall and V-baffles which are inserted at the core of the tested tube. The MVB height is separated into two parts; b1 represents the MVB height on the tube wall, while b2 represents the MVB height at the core of the tested round tube. The MVB height to tube diameter ratios, b/D, are adjusted; b₁/D = 0.05, 0.1, 0.15… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.20

Abstract Numerical analysis of fluid flow mechanism and heat transfer in a heat exchanger duct (HXD) with dual-inclined baffles (DIB) are reported. Three DIB types are examined: 1. “Type A” is located at the center of the HXD, 2. “Type B” is located on the upper-lower duct walls (as an orifice) and 3. “Type C” is a combination of the type A and B (as double orifices). The impacts of the ratio of DIB heights (b) to the square duct height (H; b/H) on increased heat transfer and friction loss are analyzed. Laminar flow (Re = 100 – 2000 based on… More >

Boonchai Lertnuwat

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.1

Abstract The aim of this work is to numerically investigate the effect of mounting winglet vortex generators on different positions in rectangular-duct-type air heaters. The two investigated positions were the absorber plate and the insulation plate, opposite to the absorber plate. Four shapes of winglet vortex generator, i.e. perforated rectangular winglet vortex generators (P-RWVG), rectangular winglet vortex generators (RWVG), perforated trapezoidal winglet vortex generators (P-TWVG) and trapezoidal winglet vortex generators (TWVG), were used. Results showed that heat-transfer capability would be better if the winglet vortex generators were mounted on the opposite insulation plate in the cases of P-RWVG, RWVG and P-TWVG. More >

A.C. Budiman^a,*, S. M. Hasheminejad^b, Sudirja^a, A. Mitayani^c, S. H. Winoto^d

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.9

Abstract Streamwise development of counter-rotating vortices induced by three different types of chevron Vortex Generators (VGs) placed upstream an Electric Vehicles (EV) dummy battery module is experimentally visualized using a smoke-wire method. From the single chevron reference case, the mushroom-like vortices do not collapse until passing the module. When more chevrons are used in line, the vortices become more prominent. It can also be observed that the vortex sizes and shapes are significantly influenced by the spanwise base length of the chevron. The induced vortices from all three VGs suggest a potential heat transfer augmentation for the EV battery module application. More >

Alim Al Ayub Ahmed^1,*, Salim Oudah Mezan², Binyamin³, Murtadha Doghiam Abdullah⁴, Elena Tesleva⁵, Linar G. Akhmetov⁶, Rustem Zalilov⁷, Mustafa M. Kadhim^8,9,10, Abduladheem Turki Jalil^11,12

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 15-24, 2023, DOI:10.32604/fdmp.2022.019922

Abstract The utilization of vortex generators to increase heat transfer from cylinders installed inside a duct is investigated. In particular, a channel containing eight cylinders with volumetric heat sources is considered for different values of the Reynolds number. The effective possibility to use vortex generators with different sizes to increase heat transfer and, consequently, reduce the surface temperature of the cylinders is examined. Also, the amount of pressure drop inside the channel due to the presence of vortex generators is considered and compared with the cases without vortex generators. The results show that although the addition of generators increases the pressure… More >

Rachid Maouedj¹, Younes Menni², Mustafa Inc^3,4,*, Yu-Ming Chu^5,6,*, Houari Ameur⁷, Giulio Lorenzini⁸

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 855-889, 2021, DOI:10.32604/cmes.2021.014524

Abstract Re-engineering the channel heat exchangers (CHEs) is the goal of many recent studies, due to their great importance in the scope of energy transport in various industrial and environmental fields. Changing the internal geometry of the CHEs by using extended surfaces, i.e., VGs (vortex generators), is the most common technique to enhance the efficiency of heat exchangers. This work aims to develop a new design of solar collectors to improve the overall energy efficiency. The study presents a new channel design by introducing VGs. The FVM (finite volume method) was adopted as a numerical technique to solve the problem, with… More >

Mohamed Salmi^1,2, Younes Menni³, Ali J. Chamkha^4,5,*, Houari Ameur⁶, Rachid Maouedj⁷, Ahmed Youcef⁷

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 147-173, 2021, DOI:10.32604/cmes.2021.012839

Abstract The hydrothermal behavior of air inside a solar channel heat exchanger equipped with various shaped ribs is analyzed numerically. The bottom wall of the exchanger is kept adiabatic, while a constant value of the temperature is set at the upper wall. The duct is equipped with a flat rectangular fin on the upper wall and an upstream V-shaped baffle on the lower wall. Furthermore, five hot wall-attached rib shapes are considered: trapezoidal, square, triangular pointing upstream (type I), triangular pointing downstream (type II), and equilateral-triangular (type III) cross sections. Effects of the flow rates are also inspected for various Reynolds… More >

Yong Guan¹, Wanling Hu^{1, 2, *}, Yun Zhang¹, Kewei Song^{2, 3}, Liangbi Wang^{2, 3}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 237-256, 2020, DOI:10.32604/cmes.2020.09141

Abstract The application of vortex generators in tube-finned heat exchangers is very universal. The vortex generators can generate secondary flow, and as we all know secondary flow can obviously strengthen heat transfer. To use vortex generators much more efficiently in the circle tube-finned heat exchangers, the intensity correlation study between secondary flow and heat transfer is needed. 22 different structures of circle tubefinned heat exchangers were numerically studied, including the plain fin cases and the cases with vortex generators. In addition, the influence of fin spacing, transverse and longitudinal tube pitch, heights and attack angle of vortex generators, positions of vortex… More >