Ritesh Singh¹, Abhishek Gupta¹, Akshoy Ranjan Paul¹, Bireswar Paul¹, Suvash C. Saha^2,*

Energy Engineering, Vol.121, No.4, pp. 835-848, 2024, DOI:10.32604/ee.2024.046849 - 26 March 2024

Abstract A parabolic trough solar collector (PTSC) converts solar radiation into thermal energy. However, low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power plants. Thermal performance of PTSC is enhanced in this study by incorporating magnetic nanoparticles into the working fluid. The circular receiver pipe, with dimensions of 66 mm diameter, 2 mm thickness, and 24 m length, is exposed to uniform temperature and velocity conditions. The working fluid, Therminol-66, is supplemented with Fe₃O₄ magnetic nanoparticles at concentrations ranging from 1% to 4%. The findings demonstrate that the inclusion of nanoparticles… More >

Fayi Yan^*, Xuejian Pei, He Lu, Shuzhen Zong

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 287-304, 2024, DOI:10.32604/fhmt.2023.045038 - 21 March 2024

Abstract As compact and efficient heat exchange equipment, helically coiled tube-in-tube heat exchangers (HCTT heat exchangers) are widely used in many industrial processes. However, the thermal-hydraulic research of liquefied natural gas (LNG) as the working fluid in HCTT heat exchangers is rarely reported. In this paper, the characteristics of HCTT heat exchangers, in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube, are studied by numerical simulations. The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity,… More >

Karema A. Hamad^*, Yasser A. Mahmood

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.11, pp. 2863-2875, 2023, DOI:10.32604/fdmp.2023.029049 - 18 September 2023

Abstract The cooling of a (pebble bed) spent fuel in a high-temperature gas-cooled reactor (HTGR) is adversely affected by an increase in the temperature of the used gas (air). To investigate this problem, a configuration consisting of three copper spheres arranged in tandem subjected to a forced mist flow inside a cylindrical channel is considered. The heat transfer coefficients and related variations as a function of Reynolds number are investigated accordingly. The experimental results show that when compared to those with only airflow, the heat transfer coefficient of the spherical elements with mist flow (j = More >

Tiezhu Sun^*, Huan Sun, Tingzheng Tang, Yongcheng Yan, Peixuan Li

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2519-2531, 2023, DOI:10.32604/fdmp.2023.027118 - 25 June 2023

Abstract The so-called indirect evaporative cooling technology is widely used in air conditioning applications. The thermal characterization of tube-type indirect evaporative coolers, however, still presents challenges which need to be addressed to make this technology more reliable and easy to implement. This experimental study deals with the performances of a tube-type indirect evaporative cooler based on an aluminum tube with a 10 mm diameter. In particular, the required tests were carried out considering a range of dry-bulb temperatures between 16°C and 18°C and a temperature difference between the wet-bulb and dry-bulb temperature of 2°C∼4°C. The integrated convective More > Graphic Abstract

Fithry Mohd Amir^*, Mohd Zamri Yusoff, Saiful Hasmady Abu Hassan

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.27

Abstract Nanofluid film on a horizontal tube is investigated numerically on the circular and multi-faceted cylinder. The fluid flow characteristics, including film thickness, shear stress, and thermal performance, are observed and analyzed. Fluid film on the circular surface is typical in many engineering applications, but the study of nanofluid film on non-circular surface is deficient in literature. The study provides a numerical model of a multi-faceted cylinder to simulate the nanofluid film on the non-circular surfaces using a volume of fluid (VOF) method. The ratio of Brownian motion to thermophoretic diffusion, N_BT developed along the film thickness More >

Dorsaf Khalifa^*, Foued Mzali

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1841-1852, 2022, DOI:10.32604/fdmp.2022.022060 - 27 June 2022

Abstract The interfacial heat transfer coefficient (IHTC) is one of the main input parameters required by casting simulation software. It plays an important role in the accurate modeling of the solidification process. However, its value is not easily identifiable by means of experimental methods requiring temperature measurements during the solidification process itself. For these reasons, an optimal experiment design was performed in this study to determine the optimal position for the temperature measurement and the optimal thickness of the rectangular cast iron part. This parameter was identified using an inverse technique. In particular, two different algorithms… More >

Kaprawi Sahim^*, Dewi Puspitasari, Nukman

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-6, 2021, DOI:10.5098/hmt.16.22

Abstract The recent trend application of the nanofluids is used in some industrial equipment such as tube heat exchanger, double pipe exchanger and shell-tube type heat exchanger. The Triangle tubes may be used in the heat exchanger. Thus, this experimental study reports the convective heat transfer performance of the aluminum oxide-water nanofluids flowing in the triangle channel. In this study, the amount of the volume fraction of the Al₂O₃ used was 0.1 %, 0.2 %, and 0.3 respectively in base-water as the nanofluids and the Reynolds numbers were varied from about 1000 to 7000. The channel was… More >

B. Gangadhara Rao^a,*, K. Elangovan^b, K. Hema Chandra Reddy^a, M. Arulprakasajothi^c

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-8, 2021, DOI:10.5098/hmt.16.15

Abstract In this research, the 3-D coupled thermal electric model analyses on a sandwich bus bar are presented for the comparison of F Class & B Class of insulation. IEC defines the maximum temperature limit at the conductor based on the class of insulation. This paper gives the clarity on the variation on the current density i.e, the size of the conductor by varying the class of insulation. The study is conducted on tin plated 2000 A sandwich busbar system. The sandwich bus bar is made of copper conductors with tin plating and enclosed by an… More >

Ammar Hassan Soheel, Omar Mahmood Jumaah, Ahmed Mustaffa Saleem^*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-7, 2021, DOI:10.5098/hmt.17.21

Abstract This paper presents a simulation and investigation of the heat transfer coefficient, pressure drop, and thermal conductivity of two - phase flow. The simulation was performed of mixtures (Al₂O₃ nanoparticles with R134a refrigerant). The size of nanoparticles (Al₂O₃) which is used in this study is 30 nm and volume concentrations are 0.015 and 0.03. The two – phase flowing through a horizontal circular microchannel of (diameter 100 µm, and length 20 mm) under constant heat flux (3000 W/m²) and constant wall temperature (330 K), also in this study used the inlet temperature at -20 oC and mass… More >

Zijie Chen^a , Sanat Modak^a, Massoud Kaviany^a,* , Richard Bonner^b

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-11, 2020, DOI:10.5098/hmt.14.1

Abstract In dropwise condensation on vertical surface, droplets grow at nucleation sites, coalesce and reach the departing diameter. In biphilic surfaces, when the hydrophobic domain is small, the maximum droplet diameter is controlled by the shortest dimension where the droplets merge at the boundary. Through direct numerical simulations this size-effect heat transfer coefficient enhancement is calculated. Then the 1-D biphilic surface is optimized considering the size-dependent hydrophilic domain partial flooding (directly simulated as a liquid rivulet and using the capillary limit), the subcooling (heat flux) and condenser length effects. The predicted performance is in good agreement More >