Shengqiang Shi^1,2,*, Abdelatif Merabtine³, Rachid Bennacer⁴, Julien Kauffmann²

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.050547

Abstract At present, air handling units are usually used indoors to improve the indoor environment quality. However, while introducing fresh air to improve air quality, air velocity has a certain impact on the occupants’ thermal comfort. Therefore, it is necessary to explore the optimization of air-fluid-body interaction dynamics. In this study, the indoor air flow was changed by changing the opening and closing degree of the blower, and the thermal manikin is introduced to objectively evaluate the human thermal comfort under different air velocities. The main experimental results show that the air change rate increases with the increase of the opening… More >

Rachid Karra^1,*, Abdelatif Maslouhi²

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.048447

Abstract Recent studies have underscored the significance of the capillary fringe in hydrological and biochemical processes. Moreover, its role in shallow waters is expected to be considerable. Traditionally, the study of groundwater flow has centered on unsaturated-saturated zones, often overlooking the impact of the capillary fringe. In this study, we introduce a steady-state two-dimensional model that integrates the capillary fringe into a 2-D numerical solution. Our novel approach employs the potential form of the Richards equation, facilitating the determination of boundaries, pressures, and velocities across different ground surface zones. We utilized a two-dimensional Freefem++ finite element model to compute the stationary… More >

Yuanyuan Zhao¹, Fujian Zhao², Guohui Li³, Wei Xu^4,*, Xiuli Wang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.047298

Abstract Self-excited oscillating jets (SOJ) are used in several practical applications. Their performances are significantly affected by structural parameters and the target distance. In this study, a geometric model of the SOJ nozzle accounting for multiple structural parameters is introduced, then the related cavitation performances and the optimal target distance are investigated using a Large-Eddy Simulation (LES) approach. Results are also provided about an experiment, which was conducted to validate the simulation results. By analyzing the evolution of the vapor volume fraction at the nozzle outlet, a discussion is presented about the effect of the aforementioned structural parameters on the cavitation… More >

Artur V. Dmitrenko^1,2,*, Vladislav M. Ovsyannikov²

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.048389

Abstract The differential equations of continuum mechanics are the basis of an uncountable variety of phenomena and technological processes in fluid-dynamics and related fields. These equations contain derivatives of the first order with respect to time. The derivation of the equations of continuum mechanics uses the limit transitions of the tendency of the volume increment and the time increment to zero. Derivatives are used to derive the wave equation. The differential wave equation is second order in time. Therefore, increments of volume and increments of time in continuum mechanics should be considered as small but finite quantities for problems of wave… More >

Nan Liu^1,2, Chen Hong^3,4,5, Xinchao Su^3,4,5, Xing Jin^1,2, Chen Jiang^3,4,5,*, Yuqi Shi^1,2, Bingkun Wang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.047427

Abstract As the velocity of a train increases, the corresponding air pumping power consumption of the brake discs increases proportionally. In the present experimental study, a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind tunnel. In particular, three upstream velocities were selected on the basis of earlier investigations of trains operating at 160, 250, and 400 km/h, respectively. Moreover, 3D steady computational fluid dynamics (CFD) simulations of the flow field were conducted to compare with the wind tunnel test outcomes. The results for a 3-car train at 180… More >

Yi Tu^1,*, Yuan Wu², Yu Zeng³

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.045624

Abstract The formation of ice on the leading edge of aircraft engines is a serious issue, as it can have catastrophic consequences. The Swirl Anti-Icing (SAI) system, driven by ejection, circulates hot fluid within a 360° annular chamber to heat the engine inlet lip surface and prevent icing. This study employs a validated Computational Fluid Dynamics (CFD) approach to study the impact of key geometric parameters of this system on flow and heat transfer characteristics within the anti-icing chamber. Additionally, the entropy generation rate and exergy efficiency are analyzed to assess the energy utilization in the system. The research findings indicate… More >

Igor B. Palymskiy^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.048829

Abstract The fully nonlinear equations of gas dynamics are solved in the framework of a numerical approach in order to study the stability of the steady mode of Rayleigh-Bénard convection in compressible, viscous and heat-conducting gases encapsulated in containers with no-slip boundaries and isothermal top and bottom walls. An initial linear temperature profile is assumed. A map of the possible convective modes is presented assuming the height of the region and the value of the temperature gradient as influential parameters. For a relatively small height, isobaric convection is found to take place, which is taken over by an adiabatic mode when… More >

Long Yu, Dongdong Pang^*, Minmin She, Hongwei Qiu, Ping Cao, Xiongwei You

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.048093

Abstract In this study, the motion of wet particles in the drying unit of a vertical powder dryer is investigated by using a Discrete element method (DEM) coupled with a liquid bridge force. In particular, by varying parameters such as the particle mass flow rates, the superficial gas velocities, and superficial gas temperatures, the influence of the moisture content on the flow behavior is examined. The results show that when the moisture content increases, the mean particle velocity decreases while the bed mean solid “holdup” and the mean residence time (MRT) of particles grow. It is also found that the local… More >

O. N. Goncharova¹, V. B. Bekezhanova^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.047959

Abstract The dynamics of a bilayer system filling a rectangular cuvette subjected to external heating is studied. The influence of two types of thermal exposure on the flow pattern and on the dynamic contact angle is analyzed. In particular, the cases of local heating from below and distributed thermal load from the lateral walls are considered. The simulation is carried out within the frame of a two-sided evaporative convection model based on the Boussinesq approximation. A benzine–air system is considered as reference system. The variation in time of the contact angle is described for both heating modes. Under lateral heating, near-wall… More > Graphic Abstract

Guochen Xu^*

FDMP-Fluid Dynamics & Materials Processing, Vol., , DOI:10.32604/fdmp.2024.048337

Abstract Microscopic pore structure in continental shale oil reservoirs is characterized by small pore throats and complex micro-structures. The adsorption behavior of hydrocarbons on the pore walls exhibits unique physical and chemical properties. Therefore, studying the adsorption morphology of hydrocarbon components in nanometer-sized pores and clarifying the exploitation limits of shale oil at the microscopic level are of great practical significance for the efficient development of continental shale oil. In this study, molecular dynamics simulations were employed to investigate the adsorption characteristics of various single-component shale oils in inorganic quartz fissures, and the influence of pore size and shale oil hydrocarbon… More >