Sabrina Meddah^1,2,*, Sid Ahmed Tadjer³, Abdelhakim Idir⁴, Kong Fah Tee^5,6,*, Mohamed Zinelabidine Doghmane¹, Madjid Kidouche¹

Structural Durability & Health Monitoring, Vol.19, No.1, pp. 77-103, 2025, DOI:10.32604/sdhm.2024.053541 - 15 November 2024

Abstract Maintaining the integrity and longevity of structures is essential in many industries, such as aerospace, nuclear, and petroleum. To achieve the cost-effectiveness of large-scale systems in petroleum drilling, a strong emphasis on structural durability and monitoring is required. This study focuses on the mechanical vibrations that occur in rotary drilling systems, which have a substantial impact on the structural integrity of drilling equipment. The study specifically investigates axial, torsional, and lateral vibrations, which might lead to negative consequences such as bit-bounce, chaotic whirling, and high-frequency stick-slip. These events not only hinder the efficiency of drilling… 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 >

Vladimir Konovalov^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2541-2563, 2024, DOI:10.32604/fdmp.2024.051219 - 28 October 2024

Abstract The regime of horizontal subcooled film boiling is characterized by the formation of a thin layer of vapor covering the surface of a flat horizontal heater. Based on the equations of motion of a viscous incompressible fluid and the equation of heat transfer, the stability of such a vapor film is investigated. The influence of the modulation of the gravity field caused by vertical vibrations of the heater of finite frequency, as well as a constant electric field applied normal to the surface of the heater, is taken into account. It is shown that in… More >

Alexey Fedyushkin^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1351-1364, 2024, DOI:10.32604/fdmp.2024.050267 - 27 June 2024

Abstract This study is devoted to an analysis of natural convection and the emergence of delamination in an incompressible fluid encapsulated in a closed region heated from the side. Weak, medium and intensive modes of stationary laminar thermal and thermo-concentration convection are considered. It is shown that nonlinear flow features can radically change the flow structure and characteristics of heat and mass transfer. Moreover, the temperature and concentration segregation in the center of the square region display a non-monotonic dependence on the Grashof number (flow intensity). The formation of a nonstationary periodic structure of thermal convection More >

Vladimir Ya. Modorskii, Ivan E. Cherepanov^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1031-1043, 2024, DOI:10.32604/fdmp.2024.048494 - 07 June 2024

Abstract A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation, storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen mixtures. Natural gas can be transported using a pipeline system with the required pressure being maintained by gas compression stations. This method, however, is affected by some problems too. Compressors emergency stops can be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibration amplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth… More >

Peter Watson¹, Sebastien Vincent Bonnieu², Marcello Lappa^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 1-29, 2024, DOI:10.32604/fdmp.2023.029280 - 08 November 2023

Abstract We present a short retrospective review of the existing literature about the dynamics of (dry) granular matter under the effect of vibrations. The main objective is the development of an integrated resource where vital information about past findings and recent discoveries is provided in a single treatment. Special attention is paid to those works where successful synthetic routes to as-yet unknown phenomena were identified. Such landmark results are analyzed, while smoothly blending them with a history of the field and introducing possible categorizations of the prevalent dynamics. Although no classification is perfect, and it is… More >

Xiaojun Huang^1,2, Liaojun Zhang^1,*, Renyu Ge², Hanbo Cui², Zhedong Xu²

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 23-41, 2022, DOI:10.32604/cmes.2022.019765 - 02 June 2022

Abstract In the current research, an effective differential quadrature method (DQM) has been developed to solve natural frequency and vibration modal functions of circular section beams along radial functional gradient. Based on the high-order theory of transverse vibration of circular cross-section beams, lateral displacement equation was reconstructed neglecting circumferential shear stress. Two equations coupled with deflection and rotation angles were derived based on elastic mechanics theory and further simplified into a constant coefficient differential equation with natural frequency as eigenvalue. Then, differential quadrature method was applied to transform the eigenvalue problem of the derived differential equation… More >

Yong Wang, Hongjian Ni^*, Ruihe Wang, Shubin Liu

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1263-1273, 2022, DOI:10.32604/fdmp.2022.020405 - 27 May 2022

Abstract A specific model is elaborated for stick-slip and bit-bounce vibrations, which are dangerous dynamic phenomena typically encountered in the context of rotary drilling applications. Such a model takes into account two coupled degrees of freedom of drill-string vibrations. Moreover, it assumes a state-dependent time delay and a viscous damping for both the axial and torsional vibrations and relies on a sawtooth function to account for the cutting force fluctuation. In the frame of this theoretical approach, the influence of rock brittleness on the stability of the drill string is calculated via direct integration of the More >

Imran M. Jamadar^1,*, B. Suresha¹, Prasanta Kumar Samal¹, S. A. I. Bellary²

Sound & Vibration, Vol.56, No.2, pp. 165-191, 2022, DOI:10.32604/sv.2022.015267 - 25 March 2022

Abstract Usage of rolling contact bearings in variety of rotor-dynamic applications has put forth a need to develop a detailed and easy to implement techniques for the assessment of damage related features in these bearings so that before mechanical failure, maintenance actions can be planned well in advance. In accordance to this, a method based on dimensional amplitude response analysis and scaling laws is presented in this paper for the diagnosis of defects in different components of rolling contact bearings in a dimensionally scaled rotor-bearing system. Rotor, bearing, operating and defect parameters involved are detailed for… More >

Y. A. Amer¹, A. T. EL-Sayed², M. N. Abd EL-Salam^3,*

Sound & Vibration, Vol.56, No.2, pp. 89-104, 2022, DOI:10.32604/sv.2022.011838 - 25 March 2022

Abstract In our consideration, a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out. Those four types are the linear velocity feedback control, the cubic velocity feedback control, the non-linear saturation controller (NSC) and the positive position feedback (PPF) controller. The suitable type is the PPF controller for suppression the vibrations of the cantilever beam. The approximate solution obtained up to the first approximation by using the multiple scale method. The PPF controller effectiveness is studied on the system. We used frequency-response More >