Ivan Karpunin^*, Denis Polezhaev

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.3, pp. 543-553, 2025, DOI:10.32604/fdmp.2025.061163 - 31 March 2025

Abstract An experimental study of the diffusive mass transfer between a droplet and an oscillating immiscible liquid in a horizontal axisymmetric Hele-Shaw cell is carried out. The liquid oscillates radially in the cell. The transverse size of the droplet exceeds the cell thickness. The viscosities of the droplet and the surrounding liquid are comparable. Relevant effort is provided to design and test an experimental setup and validate a protocol for determining the mass transfer rate of a solute in a two-liquid system. In particular, fluorescent dye Rhodamine B is considered as the solute. A critical comparison… More >

Victor Kozlov^1,*, Alsu Zimasova¹, Nikolai Kozlov²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.12, pp. 2693-2707, 2024, DOI:10.32604/fdmp.2024.052398 - 23 December 2024

Abstract The behavior of a viscous liquid film on the wall of a rapidly rotating cylinder subjected to angular vibrations is experimentally studied. The cavity is filled with an immiscible low-viscosity liquid of lower density. In the absence of vibrations, the high viscosity liquid covers the inner surface of the cylinder with a relatively thin axisymmetric film; the low-viscosity liquid is located in the cavity interior. It is found that with an increase in the amplitude of rotational vibrations, the axisymmetric interphase boundary loses stability. An azimuthally periodic 2D “frozen wave” appears on the film surface… More >

Jéssica da Silva Chagas^1,2, José Elson Soares Filho^1,2, Natália Fernanda Inocêncio Silva^1,2, Marcelo Massayoshi Ueki³, Eliton Souto de Medeiros^1,2, Renate Maria Ramos Wellen¹, Mauricio Pinheiro de Oliveira⁴, Gelsoneide da Silva Gois⁵, Yêda Medeiros Bastos de Almeida⁵, Amélia S. F. Santos^1,2,*

Journal of Renewable Materials, Vol.12, No.12, pp. 2079-2094, 2024, DOI:10.32604/jrm.2024.055361 - 20 December 2024

Abstract Poly(3-hydroxybutyrate) (PHB) is a biothechnological and biodegradable thermoplastic polymer from the polyhydroxyalkanoates (PHAs) family, whose chain regularity, high molecular weight, and physical and mechanical properties comparable to polypropylene (PP) are characteristics that have made PHB a prominent commercial bioplastic. Nevertheless, its susceptibility to thermal degradation and hydrolysis has limited many applications. To address the challenges associated with processing, a random copolymer of 95.86 mol% 3-hydroxybutyrate and 4.14 mol% 3-hydroxyvalerate (referred as PHB) was compounded without (neat PHB) and with 0.25, 0.5, 1, and 1.5 wt% of chain extender (Joncryl^®ADR 4368), consisting of multifunctional epoxy groups, and… More >

Tatyana Lyubimova^1,2,*, Yulia Garicheva², Andrey Ivantsov¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2417-2429, 2024, DOI:10.32604/fdmp.2024.052391 - 28 October 2024

Abstract External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. The computational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of square cross-section, which undergoes linearly polarized translational oscillations in weightless conditions, has been carried out. Under vibrations, the bubble moves towards the wall of the vessel with acceleration determined by the amplitudes and frequency of vibrations. Near the wall, at a distance of the order of the thickness of the viscous Stokes boundary layer, the effects of viscosity More >

Zhenjiang Zhao¹, Lei Jiang¹, Ling Bai^2,*, Bo Pan³, Ling Zhou^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1111-1136, 2024, DOI:10.32604/cmes.2024.055399 - 27 September 2024

Abstract The fluid’s viscosity significantly affects the performance of a centrifugal pump. The entropy production method and leakage are employed to analyze the performance changes under various viscosities by numerical simulation and validated by experiments. The results showed that increasing viscosity reduces both the pump head and efficiency. In addition, the optimal operating point shifts to the left. Leakage is influenced by vortex distribution in the front chamber and boundary layer thickness in wear-ring clearance, leading to an initial increase and subsequent decrease in leakage with increasing viscosity. The total entropy production inside the pump rises More >

Muhammad Shoaib Arif^1,2,*, Kamaleldin Abodayeh¹, Yasir Nawaz²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1213-1241, 2024, DOI:10.32604/cmes.2024.054819 - 27 September 2024

Abstract Fractal time-dependent issues in fluid dynamics provide a distinct difficulty in numerical analysis due to their complex characteristics, necessitating specialized computing techniques for precise and economical solutions. This study presents an innovative computational approach to tackle these difficulties. The main focus is applying the Fractal Runge-Kutta Method to model the time-dependent magnetohydrodynamic (MHD) Newtonian fluid with rescaled viscosity flow on Riga plates. An efficient computational scheme is proposed for handling fractal time-dependent problems in flow phenomena. The scheme is comprised of three stages and constructed using three different time levels. The stability of the scheme… More >

Jin Yang^1,2, Hailong Zhao¹, Jingyi Zeng¹, Ying Su^1,2, Mengdi Zhu¹, Xingyang He^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2163-2181, 2024, DOI:10.32604/fdmp.2024.055448 - 23 September 2024

Abstract To achieve higher strength and better durability, ultra-high performance concrete (UHPC) typically employs a relatively small water-binder ratio. However, this generally leads to an undesired increase in the paste viscosity. In this study, the effects of liquid and powder polycarboxylate superplasticizers (PCE) on UHPC are compared and critically discussed. Moreover, the following influential factors are considered: air-entraining agents (AE), slump retaining agents (SA), and defoaming agents (DF) and the resulting flow characteristics, mechanical properties, and hydration properties are evaluated assuming UHPC containing 8‰ powder PCE (PCE-based UHPC). It is found that the spread diameter of… More >

Mekonnen S. Ayano^1,*, Thokozani N. Khumalo¹, Stephen T. Sikwila², Stanford Shateyi³

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1153-1169, 2024, DOI:10.32604/fhmt.2024.048474 - 30 August 2024

Abstract The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver ()−Magnesium oxide () hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone, with the influence of transverse magnetic field and thermal radiation. The physical flow problem has been modeled with coupled partial differential equations. We apply similarity transformations to the non-dimensionalized equations, and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method. The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints, which are illustrated graphically. The More >

Victor Kozlov^1,*, Vladimir Saidakov¹, Nikolai Kozlov²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 693-703, 2024, DOI:10.32604/fdmp.2024.048068 - 28 March 2024

Abstract The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally studied. The layer has a circular axisymmetric boundary. In the absence of modulation of the rotation speed, the interphase boundary has the shape of a short axisymmetric cylinder. A new effect has been discovered, under the influence of rotation speed modulation, the interface takes on a new dynamic equilibrium state. A more viscous liquid covers the end boundaries of the layer in the form of thin films, which have the shape of round… More >

Hanumesh Vaidya¹, Fateh Mebarek-Oudina^2,*, K. V. Prasad¹, Rajashekhar Choudhari³, Neelufer Z. Basha¹, Sangeeta Kalal¹

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 65-78, 2024, DOI:10.32604/fhmt.2024.047879 - 21 March 2024

Abstract This investigation aims to analyze the effects of heat transport characteristics in the unsteady flow of nanofluids over a moving plate caused by a moving slot factor. The BRS variable is utilized for the purpose of analyzing these characteristics. The process of mathematical computation involves converting the governing partial differential equations into ordinary differential equations that have suitable similarity components. The Keller-Box technique is employed to solve the ordinary differential equations (ODEs) and derive the corresponding mathematical outcomes. Figures and tables present the relationship between growth characteristics and various parameters such as temperature, velocity, skin More > Graphic Abstract