Article
Thermodynamics
Z. Abbas, A. Shakeel, M. Y. Rafiq, S. Khaliq, J. Hasnain, A. Nadeem
Summary: The recent investigations have highlighted the significance of the effect of an endoscope on the peristaltic flow, which has numerous clinical applications in medical diagnosis. This study focuses on the problem of peristaltic flow with heat and mass transfer through the gap between coaxial inclined tubes. The results reveal the impact of parameters on the fluid velocity, frictional forces, and pressure rise per wavelength, providing valuable insights for medical practitioners.
ADVANCES IN MECHANICAL ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Nnamdi Fidelis Okechi
Summary: This paper presents a theoretical model to predict the effects of surface roughness in slip flow regime compared to continuum flow in a curved microchannel. The surface roughness is structured as one-directional sinusoidal corrugations. The flow rate generated by a pressure gradient across the corrugations is obtained analytically using the domain perturbation technique. The study reveals that the presence of roughness decreases the flow in the slip regime when compared to a smooth curved channel flow. Additionally, the results show that as the wavenumber of the roughness increases during the transition from continuum flow to slip flow regime, the effects due to surface roughness may become more profound.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Thermodynamics
Xinping Ouyang, Huihui Hu
Summary: In this study, a heat transfer experiment was conducted on circular finned tubes, and numerical simulation was carried out to verify the accuracy of the model. The heat transfer and flow characteristics on the air side of staggered corrugated finned tubes and equidistant corrugated finned tubes were simulated. The relationships between the number and height of corrugations and the air heat transfer and pressure drop on the shell side were obtained. The results showed that the corrugated finned tube with optimized structure outperformed the flat finned tube, and the equidistant corrugated finned tube performed better than the staggered corrugated finned tube.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Mathematics, Applied
P. Naga Lakshmi Devi, Phani Kumar Meduri
Summary: In this article, an exact solution for the flow of couple stress fluid past a contaminated fluid sphere is obtained using interfacial slip boundary condition. The solution considers different regions with and without cap. The velocity is expressed in terms of stream function and the drag coefficient is calculated. Special cases of a no-slip condition and a solid sphere are also studied and compared with existing literature. The results are in good agreement. Additionally, the flow of contaminated fluid past a couple stress fluid sphere and the flow of couple stress fluid past a contaminated viscous sphere are examined.
APPLIED MATHEMATICS AND COMPUTATION
(2023)
Article
Thermodynamics
Yan Cao, Hamdi Ayed, Ali E. Anqi, Omid Tutunchian, Hamed Sadighi Dizaji, Samira Pourhedayat
Summary: This paper introduces and investigates a helical tube-in-tube heat exchanger with both inner tube and outer tube corrugated. The fabrication process and performance analysis show that this structure can significantly boost the thermal capacity of the heat exchanger, with the relative position of the corrugations playing a crucial role in performance improvement.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Engineering, Mechanical
Shaoyu Zhu, Xiangjun Zhang
Summary: The modified average Reynolds equation for friction pairs with arbitrary three-dimensional rough surfaces lubricated by couple stress fluid is derived. The performance parameters under various factors, such as couple stress, surface roughness, journal misalignment, and thermal effect, are obtained using the finite difference numerical method. The results show that the surface roughness factor plays an important role in the performance of the friction pairs, even with small nominal eccentricity ratios.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Mechanical
Neminath Naduvinamani, Ashwini Angadi
Summary: This study investigates the dynamic characteristics of the Rayleigh step bearing with the influence of surface roughness and a porous medium. The results show that the couple stress fluid has a significant impact on the load-carrying capacity, stiffness, and damping coefficients of the bearing. Additionally, negatively skewed roughness reduces the volume flow rate.
Article
Mathematics
Samuel Olumide Adesanya, Tunde Abdulkadir Yusuf, Ramoshweu Solomon Lebelo
Summary: This paper presents a mathematical investigation of the flow and heat transfer behavior of reactive magnetic fluids containing nanostructures. The studied fluid flows through inclined magnetized solid boundaries for energy conversion. The effects of various fluid parameters on velocity, temperature, skin friction, and heat transfer rates are analyzed and discussed. The findings suggest that enhanced couple of stress fluid and variable viscosity parameters can reduce skin drag and heat transfer rate, while increasing the couple stress parameter encourages thermal instability in the flow domain.
Article
Chemistry, Physical
Zhiwei Wu, Caifu Qian, Gang Liu, Zhisheng Liu, Ping Sheng
Summary: Conically corrugated tubes, suitable for heat exchangers, have lower axial elasticity but higher yield and ultimate strength, developing three-dimensional stress under axial tensile load. Their heat transfer coefficient is higher than other corrugated tubes and smooth tubes.
Article
Engineering, Mechanical
K. Gangadhar, P. Manasa Seshakumari, M. Venkata Subba Rao, Ali J. Chamkha
Summary: In this study, the physical features of bioconvective MHD flow of couple stress fluid over an upper horizontal surface are analyzed, considering radiation and viscous dissipation effects. By solving ordinary differential equations numerically, the variations of velocity, temperature, concentration, friction factor, and local heat and mass transfer rates are observed. The results show that velocity decreases with increasing couple stress and magnetic parameter, while temperature increases. The thermal boundary layer increases with the Brinkman number, while the concentration boundary layer decreases.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2022)
Article
Multidisciplinary Sciences
Aya M. Ismael, Nabil T. Eldabe, Mohamed Y. Abou Zeid, Sami M. El Shabouri
Summary: This study analyzes the effects of couple stresses on the peristaltic transport of a micropolar non-Newtonian nanofluid. By using simplified governing equations and obtaining semi-analytical solutions, numerical results of various variables with physical parameters are presented, and the trapping phenomenon is discussed. This study is of great significance in medical applications and cancer treatment.
SCIENTIFIC REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Takuma Kishimoto, Saki Suematsu, Hayate Sakaguchi, Kenichi Tashima, Satoshi Kajino, Shiori Gondo, Shinsuke Suzuki
Summary: The crystal orientation plays a crucial role in suppressing the development of inner surface roughness during hollow sinking, and crystal grains with {102} crystal planes vertical to the normal direction to the inner surface were found to be effective in this process. Additionally, decreasing wall thickness resulted in the rotation of crystal grains so that the {102} crystal plane was parallel to the normal direction, which contributed to the suppression of inner surface roughness development.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
Huiting Shi, Shengqiang Yang, Xiuhong Li, Wenhui Li, Huixin Zhang
Summary: The research shows that hydrogen peroxide and triethanolamine oleate can enhance the wettability of grinding fluid, with A3 grinding fluid having the best surface roughness and brightness. Barrel finishing achieves low-stress plastic deformation, restricting the formation of subsurface damage.
MATERIALS AND MANUFACTURING PROCESSES
(2021)
Article
Engineering, Multidisciplinary
F. Ahmad, M. Nazeer, W. Ali, A. Saleem, H. Sarwar, S. Suleman, Z. Abdelmalek
Summary: This paper discusses numerical and analytical solutions of the Stokes theory of couple stress fluid under the effects of constant, space, and variable viscosity in an inclined channel. The perturbation technique is utilized to transform the dimensional form of the boundary value problem into dimensionless form, and analytical expressions for velocity and temperature are presented. The validity of the perturbation solution is confirmed using the Pseudo-Spectral collocation method for different viscosity models.
Article
Mathematics, Applied
K. M. Surabhi, Arpitha Ravikanti, D. Srikanth, D. Srinivasacharya
Summary: This study investigates the hemodynamics of nanofluid in a stenotic bifurcated artery, modeling blood as a couple stress fluid and solving coupled non-linear equations using the homotopy perturbation method. It is found that couple stress nanofluid exhibits high wall shear stress at the location of maximum constriction.
APPLIED MATHEMATICS-A JOURNAL OF CHINESE UNIVERSITIES SERIES B
(2021)
Article
Mechanics
E. A. Ashmawy
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2015)
Article
Mechanics
H. H. Sherief, M. S. Faltas, E. A. Ashmawy, A. M. Abdel-Hameid
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2016)
Article
Physics, Multidisciplinary
E. A. Ashmawy
EUROPEAN PHYSICAL JOURNAL PLUS
(2016)
Article
Physics, Multidisciplinary
E. A. Ashmawy
EUROPEAN PHYSICAL JOURNAL PLUS
(2017)
Correction
Physics, Multidisciplinary
E. A. Ashmawy
EUROPEAN PHYSICAL JOURNAL PLUS
(2017)
Article
Mechanics
E. A. Ashmawy
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2018)
Article
Mechanics
H. H. Sherief, M. S. Faltas, E. A. Ashmawy, M. G. Nashwan
Article
Mechanics
E. A. Ashmawy
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2019)
Article
Mechanics
Tarek H. Shehadeh, E. A. Ashmawy
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2019)
Article
Mechanics
Noura S. Alsudais, Shreen El-Sapa, E. A. Ashmawy
Summary: This study investigates the quasi-steady translational motion of an incompressible couple stress fluid confined between two eccentric spherical surfaces. The drag force experienced by the fluid flow on the spherical particle is numerically obtained and represented through tables and graphs. The results show that the drag force increases monotonically with the increase in the radii ratio and the couple stress viscosity parameter.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2022)
Article
Multidisciplinary Sciences
S. A. Slayi, E. A. Ashmawy
INTERNATIONAL JOURNAL OF ADVANCED AND APPLIED SCIENCES
(2019)
Article
Multidisciplinary Sciences
S. S. Ilani, E. A. Ashmawy
JOURNAL OF TAIBAH UNIVERSITY FOR SCIENCE
(2018)
Article
Multidisciplinary Sciences
N. S. Miari, E. A. Ashmawy
JOURNAL OF TAIBAH UNIVERSITY FOR SCIENCE
(2018)
Article
Engineering, Multidisciplinary
E. A. Ashmawy
ALEXANDRIA ENGINEERING JOURNAL
(2016)
Article
Mechanics
Essam Nabil Ahmed, Alessandro Bottaro
Summary: This study focuses on the fully developed, steady, incompressible, laminar flow in a channel with rough and/or permeable walls. The influence of micro-structured boundary surfaces on the flow behavior is simulated using high-order effective boundary conditions derived from homogenization theory without empirical parameters. A closed-form solution of the Navier-Stokes equations is obtained for the flow in the channel, incorporating slip velocities, shear stress, and streamwise pressure gradient at each virtual boundary. The accuracy and applicability of the model are validated against full feature-resolving simulations for different textures. The Stokes-based model used to identify slip and interface permeability coefficients in the effective boundary conditions is reliable and accurate up to a certain threshold, beyond which advective effects need to be considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Mustafa Turkyilmazoglu, Faisal Z. Duraihem
Summary: Thermally-driven natural convection in a porous layer is explored theoretically in this work based on Darcy's law. The study focuses on the non-circulating basic cellular flow between two infinitely long horizontal plates and its instability onset. The results show that a circulatory flow and temperature variation along the horizontal axis govern the motion, and the instability can be determined through linear stability analysis and numerical calculations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
P. Roca Ramis de Ayreflor, A. Viudez
Summary: In this study, the inelastic interactions between a small, intense dipole and a weak, neutral monopole in two-dimensional flows are examined. It is found that dipoles with small size but large amplitude can cross and scatter off the neutral vortex, while leaving the vortex stable.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Nilanjan Mondal, Chirodeep Bakli
Summary: This study presents a micro-nanochannel junction with directional flow achieved by a combination of junction geometry and wall functionalization. The system acts as a fluid diode with asymmetric pressure drop and flow rate in the nanochannel. The directional junction transport can be tuned with slip length, providing a key parameter for engineering various applications. The findings contribute to the understanding of flow rectification systems in nanochannels and have implications for capillary blood flow, desalination systems, and energy storage devices.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Ussama Ali, Anas Ghannam, Md Islam, Isam Janajreh
Summary: This study utilizes a passive flow control technique involving a slit through a circular structure to dampen flow-induced vibration. The results demonstrate that the presence of a slit can decrease lift and drag coefficients and suppress flow-induced vibration.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sebastian A. Altmeyer
Summary: This article investigates how an alternating magnetic field can restrict and suppress the generation of vortices in ferrofluidic Couette flow. It finds that when the initially rotating outer cylinder is suddenly stopped, more complex vortex dynamics are generated in the system, and the presence of an alternating magnetic field can modify these dynamics, mainly depending on the modulation amplitude of the field.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Pradeep, L. P. Singh
Summary: This study focuses on the analytical solution to the Riemann problem for a 1-D non-ideal flow of dusty gas with external force. The elementary wave curves, including rarefaction wave, shock wave, and contact discontinuity, were obtained and their implications on density, velocity of flow, and shock speed were examined. The addition of external force results in non-self-similar solutions.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Meng Fan, Antoine Dazin, Gerard Bois, Francesco Romano
Summary: This study investigates the prominent features of the primary instabilities of a turbulent source flow between finite-span parallel rings with spatially modulated inflow conditions rotating at angular rate n. Two different two-dimensional instabilities that occur at large and low flow rates have been traced back to two different physical mechanisms related to jet-wake and mean-core flow, respectively. The effect of the radial aspect ratios on the instability characteristics of the flow between parallel rings is also considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Yasmin Hengster, Martin Lellep, Julian Weigel, Matthew Bross, Johannes Bosbach, Daniel Schanz, Andreas Schroder, Florian Huhn, Matteo Novara, Daniel Garaboa Paz, Christian J. Kahler, Moritz Linkmann
Summary: Using curvature and torsion to describe Lagrangian trajectories provides insights into small and large time scales. Probability density functions (PDFs) of curvature and torsion were calculated for experimental Lagrangian trajectories in different flows, and were compared with experimental and numerical simulation results. The effect of anisotropy on geometry or tracer particle trajectories was quantified using the curvature vector, which was found to be related to velocity fluctuations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Nang X. Ho, Truong V. Vu
Summary: The present paper reports numerical results on the solidification process of a hollow drop on an inclined surface. The drop undergoes deformation and forms an asymmetric tip as the surface angle increases. The solidification time, however, is not affected by the surface angle. The fluid accumulates at the bottom of the drop and the bubble moves upwards before being trapped by solidification. A larger bubble reduces the tip shift. The effect of Bond number and Stefan number on solidification is also considered.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Idalia Jagodzinska, Bartosz Olszanski, Konrad Gumowski, Slawomir Kubacki
Summary: This study investigates the characteristics of high subsonic and transonic flows through a linear cascade using experimental investigations and numerical simulations. The experiments measured static pressure, flow field, and turbulent intensity, and provided inlet conditions for the numerical simulations. The simulations validated the experimental data and tested the applicability of the turbulence models.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Kun Sung Park, Ali Zamiri, Minsuk Choi, Byung Ju Lee, Jin Taek Chung
Summary: In this study, the stator geometry of a single-stage transonic fan was optimized to improve its aerodynamic performance and stall margin. Steady and unsteady simulations were conducted to analyze the impact of shock waves generated by the rotor blade on the stator inlet flow. Using a design of experiment and response surface method, an optimal geometry of the stator blade was obtained to increase the fan's efficiency and stall margin.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Yuanzhao Zhang, Bo Li
Summary: This study investigated the effects of longitudinal and lateral spacing on the aerodynamic drag characteristics of the whole team and each member in speed skating team pursuit competition. The results showed that decreasing the longitudinal spacing resulted in greater drag reduction for the whole team and individual skaters. Furthermore, lateral movement of the leading skater also led to additional drag reduction for the team. Computational fluid dynamics simulations revealed differences in drag distribution between the leading skater and the middle and last skaters.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sichang Xu, Chris Peirone, Eugene Ryzer, Gary W. Rankin
Summary: This paper presents a study of a special bistable load-type supersonic fluidic oscillator capable of producing self-sustained oscillations in two gas pressure chambers. The experimental portion verifies the robust nature of the device performance and shows distinct differences compared to a similar prototype. A three-dimensional computational fluid dynamics model is required to accurately simulate the transient filling process, leading to an unaffordable computational cost. To address this issue, a low-order fluid circuit model is developed, which provides an accurate and rapid prediction of the transient performance.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Sampson Davis, Eli Shellabarger, James Miller, Thomas Ward
Summary: The present work focuses on studying the effects of shock wave - boundary layer interaction in 2D hypersonic flow at the sharp leading edge of a flat plate and a flat plate followed by a compression ramp. A key parameter, the hypersonic interaction parameter x, is defined and analyzed using a semi-analytic reduced-order model. The study aims to improve on existing methods by characterizing the viscous boundary layer and investigating the upstream influence resulting from the compression ramp.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)