The article presents the mixed finite element formulation for examining the biomagnetic fluid dynamics as governed by the Navier–Stokes equation, coupled with energy and magnetic expressions. Both ferrohydrodynamics and magnetohydrodynamics describe the additional magnetic effects. For model discretization, the Galerkin weighted residual method was performed. Departing from a good agreement with existing findings, a biomagnetic flow (blood) in a straight rectangular conduit was then simulated in the presence of a spatially changing magnetic distribution. By virtue of negligible spatial variation influence from the magnetic field, the effects of Lorentz force were not presently considered. It was further found that the model accurately exhibits the formation and distribution of vortices, temperature, and skin friction located adjacent to and remotely from the source of magnetic load following a rise in the magnetic intensity.

Crack formation in concrete is inevitable. The cracks allow the penetration of harmful substances which may decrease the durability and the service life of concrete structures. Self-healing concrete is therefore emerging as an innovative construction material to tackle the cracking issues. In recent years, microbial self-healing concrete is garnering interest from many researchers due to its environmentally-friendly nature and the concrete compatibility of microbially-induced calcium carbonate precipitation. Various metabolic mechanisms have been used for microbial self-healing concrete production and urea hydrolysis is the most preferable metabolic pathway due to its fast and high precipitation of calcium carbonate. In this paper, a comprehensive review on the research progress on microbial self-healing concrete is presented together with the numerical modelling of microbial self-healing concrete. The challenges and limitations of microbial self-healing concrete are discussed along with the recommendations for its prospective uses in the construction industry. It is found that the survival of bacteria through direct addition technique is limited and needs further investigation. The immobilization technique gives a promising result in durability properties but doesn’t reach the mechanical requirement. Moreover, a comprehensive assessment of self-healing efficiency is required, and more efforts are needed to improve from laboratory scale to large-scaled application.

Drilling risers used in oil and gas operations are subjected to external loads such as wave and current. One of the phenomena that arise from the external loads is the Vortex-Induced Vibration (VIV), which affects the performance of the riser due to excessive vibration from the vortex shedding. A significant factor influencing the VIV is the design of the drilling riser and its auxiliary lines. Until now, the optimum geometrical size and gap between the auxiliary and the main riser are still very scarcely studied. In this paper, the main objective is to study the effects of the gap ratio (G/D) on the vortex shedding phenomenon on a fixed and freely vibrating riser. The riser system was modelled with a main drilling riser and six auxiliary lines with a constant diameter ratio (d/D) of 0.45 and gap ratio (G/D) = 0 to 2.0 in the laminar flow regime with Reynold Number, Re = 200. The simulations were conducted for Single Degree of Freedom (SDOF) using Computational Fluid Dynamics (CFD) software, Altair AcuSolve. It was found that the freely vibrating riser experienced higher lift and drag forces as compared to the fixed riser due to the synchronization (lock-in) of the shedding vibration and the natural frequencies. The lock-in phenomenon is normally observed on the drilling riser at different current directions. The forces are reduced when G/D is higher. The vortex shedding was significantly reduced for auxiliaries between 0.3 to 1.4. It is confirmed that by modifying the interaction of the vortices in the wake region with auxiliary lines, the hydrodynamic forces will be decreased. Finally, this fundamental study could potentially be used in the designing stage of an optimum drilling riser system by considering significant governing factors.

The least-squares finite element method (LSFEM) is successfully employed for the discretization of the Stokes equations and the numerical computation of the behaviour of two-dimensional Stokes flow in a straight rectangular channel under the effect of a point-source magnetic field. LSFEM has several advantages in terms of theory and computing, where it can always create a symmetric, positive-definite algebraic system of equations. It also allows for using an equal order shape function for both velocity and pressure, and it is not required to satisfy the Ladyzhenskaya–Babuška–Brezzi (LBB) condition. Despite this, LSFEM has an issue where low-order nodal expansions tend to lock. Thus, the present study proposes the discretization of the problem domain using higher-order nodes elements with full numerical integration. Results concerning velocity contour and streamlines pattern are shown. On the basis of current findings, it can be concluded that the LSFEM can be used to solve Stokes flow problem under the point source magnetic field.

This study proposes an enhanced Volume of Fluid (VOF) model incorporating dynamic contact angle (DCA) effects to improve capillary flow predictions in encapsulation-based self-healing concrete. While the classical Lucas-Washburn equation (LWE) assumes a constant contact angle, leading to overestimations in capillary rise, this work integrates time-dependent (TDCA) and velocity-dependent (VDCA) DCA models to better capture interfacial dynamics at the meniscus. Simulations demonstrated that the VDCA model reduced mean absolute errors from 17.0 to 42.9% (constant angle) to 3.1–5.3%, aligning closely with experimental data and modified LWE predictions. Oscillations around equilibrium heights, prevalent in constant-angle simulations, were significantly mitigated, though minor inertial effects persisted in wider cracks (e.g., 1 mm). The VDCA framework also extended applicability across crack widths (0.261–1 mm), offering flexibility beyond the TDCA model’s geometry-specific limitations. However, validation was restricted to water in planar cracks, highlighting the need for future parameterization of non-Newtonian agents (e.g., polymers) and complex crack geometries. This work advances capillary flow modeling in self-healing systems by emphasizing the necessity of dynamic wetting behavior, while underscoring the importance of substrate-fluid calibration for real-world implementation.

The relative impacts of changes in the storage capacity of a reservoir are strongly influenced by its hydrodynamics. This study focused mainly on predicting the flow velocities and assessing the effectiveness of groynes as control mitigation structures in changes in the water depth and velocity distributions in Ringlet Reservoir. Initially, the physical model of the Habu River (the main part of Ringlet Reservoir) was fabricated, and flow velocities were measured. Then, a two-dimensional HEC-RAS was adapted to numerically simulate the hydrodynamics of the annual recurrence intervals of 1, 5, and 100 years in the Ringlet Reservoir. Experimental data acquired at the Hydraulic and Instrumentation Laboratory of the National Water Research Institute of Malaysia (NAHRIM) was used to calibrate and validate the numerical models. The comparison of simulation and experimental results revealed that the water levels in all simulations were consistent. As for the velocity, the results show a comparable trend but with a slight variation of results compared to the experiments due to a few restrictions found in both simulations. These simulation results are deemed significant in predicting future sediment transport control based on hydrodynamics in this reservoir and can be of future reference.