Hongzhi Xu^1,2, Jian Wang^1,3, Shuxia Li^1,*, Fengrui Zhao¹, Chengwen Wang¹, Yang Guo¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 505-523, 2024, DOI:10.32604/fdmp.2023.030604

Abstract Natural gas hydrate (NGH) is generally produced and accumulated together with the underlying conventional gas. Therefore, optimizing the production technology of these two gases should be seen as a relevant way to effectively reduce the exploitation cost of the gas hydrate. In this study, three types of models accounting for the coexistence of these gases are considered. Type A considers the upper hydrate-bearing layer (HBL) adjacent to the lower conventional gas layer (CGL); with the Type B a permeable interlayer exists between the upper HBL and the lower CGL; with the type C there is… More >

Manimaran Renganathan, Thundil Karuppa Raj Rajagopal^*

Frontiers in Heat and Mass Transfer, Vol.4, No.1, pp. 1-11, 2013, DOI:10.5098/hmt.v4.1.3008

Abstract In this work, fuel spray parameters are studied by varying the fuel temperature. To overcome the tedious experimental task, a 3-D Computational Fluid Dynamics methodology is adopted by injecting fuel at specified temperatures of 313 K, 353 K and 393 K. The validation is accomplished after the optimal spatial and temporal steps of discretization are found out. At a fuel temperature of 313 K, advancing the injection timing from 6 deg bTDC to 20 deg bTDC increases cylinder peak pressure from 79.8 bar to 90.9 bar. Relation between the emission characteristics and spray SMD and More >

Zhuohuan Hu^a,*, Lulu Wang^a, Hui Wang^b, Mo Yang^a

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-8, 2015, DOI:10.5098/hmt.6.16

Abstract A numerical investigation was conducted to study the heat transfer in an aircraft cabin and the effects of air distribution under different angle and inlet velocity conditions. The Reynolds-averaged Navier–Stokes equations and the low Reynolds number turbulence model were used to simulate the airflow in the cabin. Mathematical statistics was used to process the relevant data, and statistical results revealed that different inlet angles and velocities significantly affect air temperature and flow field. The study also determined a set of optimum matching inlet vane angles and inlet velocities that result in an environment which meets More >

Ayad S. Abedalh^*, Sohaib Hassan Mohammed

Frontiers in Heat and Mass Transfer, Vol.21, pp. 227-243, 2023, DOI:10.32604/fhmt.2023.041777

Abstract Solar energy, a renewable resource, can be harnessed instead of fossil fuels to generate power and heat. One effective method for converting solar energy into heat is through a solar air heating (SAH) system. The theoretical investigation focused on the thermal performance of various V-groove angles on a corrugated absorber plate. The researchers maintained the exterior dimensions and constraints of the absorber plate while increasing its surface area by using a corrugated absorber surface. For the simulation, three different V-groove angles were employed: 45°, 30°, and 15°. The temperature and air flow rate into the… More > Graphic Abstract

Amnart Boonloi¹, Withada Jedsadaratanachai^2,*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 317-336, 2023, DOI:10.32604/fhmt.2023.044929

Abstract Thermal performance enhancement in a square channel heat exchanger (HX) using a passive technique is presented. Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvement. The vortex turbulator of interest is discrete X-V baffles (XVB). The discrete XVBs are inserted in the square channel with the main aim of generating vortex flow. The vortex flow generated can support the enhanced convective heat transfer coefficient and also enhance HX performance. Effects of baffle configuration (type A and B), baffle size (w/H = 0.05, 0.10, 0.15 and 0.20), baffle… More > Graphic Abstract

Meng Jia, Mingjun Pang^*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 337-366, 2023, DOI:10.32604/fhmt.2023.044286

Abstract The interphase mass, heat transfer efficiency, and flow resistance are strongly dependent on bubble size in gasliquid two-phase systems, so it is very important for engineering applications to effectively control bubble size. In this paper, the formation, growth, and detachment of single bubbles in Newtonian liquids based on capillary needles were studied in detail using a volume of fluid method. The authors investigated the effects of gas injection velocity, gravitational level, surface tension coefficient, needle radius, and liquid−phase properties (liquid viscosity and density) on the process of bubble generation, and the effects of the above… More >

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… More >

Shiyang Song^1,*, Tongxin Han²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 127-145, 2024, DOI:10.32604/fdmp.2023.030137

Abstract Aiming to mitigate the aerodynamic lift force imbalance between pantograph strips, which exacerbates wear and affects the current collection performance of the pantograph-catenary system, a study has been conducted to support the beam deflector optimization using a combination of experimental measurements and computational fluid dynamics (CFD) simulations. The results demonstrate that the size, position, and installation orientation of the wind deflectors significantly influence the amount of force compensation. They also indicate that the front strip deflectors should be installed downwards and the rear strip deflectors upwards, thereby forming a “π” shape. Moreover, the lift force More >

Abdourahamane Salifou Adam¹, Hatem Mrad¹, Haykel Marouani^2,*, Yasser Fouad³

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2845-2865, 2023, DOI:10.32604/cmes.2023.030777

Abstract A high percentage of failure in pump elements originates from fatigue. This study focuses on the discharge section behavior, made of ductile iron, under dynamic load. An experimental protocol is established to collect the strain under pressurization and depressurization tests at specific locations. These experimental results are used to formulate the ultimate pressure expression function of the strain and the lateral surface of the discharge section and to validate finite element modeling. Fe-Safe is then used to assess the fatigue life cycle using different types of fatigue criteria (Coffin-Manson, Morrow, Goodman, and Soderberg). When the… 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 >