Corrosive waste-heat recovery systems suffer material degradation, performance loss and high maintenance when conventional metallic heat exchangers face chloride-, carbonate- and sulfur-bearing condensates. This study presents a multiphysics CFD-electrochemical assessment of silicon carbide (SiC) for heat exchangers, via a 3D shell-and-tube model in COMSOL Multiphysics coupling turbulent flow, conjugate heat transfer, species transport and electrochemical corrosion. The thermal model considered high-pressure ammonia (tube side) and pressurized water (shell side); the corrosion model represented a flue-gas condensate/electrolyte containing Cl\(^-\), NH\(_4^+\), HCO\(_3^-\), CO\(_3^{2-}\), HSO... More >

This paper analytically investigates unsteady, laminar, magnetohydrodynamic (MHD) mixed convective oscillatory flow of two immiscible viscous fluids through a horizontal two-phase channel. The channel consists of a porous upper region (Region~I, $0 \le y \le h$) and a non-porous lower region (Region~II, $-h \le y \le 0$), separated by a permeable interface, with a uniform transverse magnetic field $B_0$ applied normal to the flow. The governing equations incorporate thermal buoyancy ($Gr$), concentration buoyancy ($Gc$), Darcy porous resistance, thermal radiation (Rosseland approximation), volumetric heat generation/absorption, first-order destructive chemical reaction, and the Soret effect... More >

This paper presents a coupled numerical-analytical framework for investigating the influence of the oil film dynamics on the vibration characteristics of the hydraulic piston pump. A finite difference solver is developed to compute the hydrodynamic pressure distribution in the distribution plate under realistic operating conditions, from which equivalent stiffness and damping coefficients are extracted using analytical squeeze-film relations and integrated into a single-degree-of-freedom vibration model. For the baseline case (\( \mu = 7.7 \times 10^{-4} \, \text{Pa·s}, \, \omega = 4000 \, \text{rpm}, \, p_p = 21.5 \, \text{MPa}, \, \gamma = 14^\circ \)), the simulation yields a mean pressu... More >

This study investigates the heat transfer and Marangoni convection flow of a hybrid Al$_2$O$_3$-Cu/water nanofluid over a stretching/shrinking sheet. Surface tension-driven thermal Marangoni convection arises from the wall temperature gradient. The novel aspects include the combined effects of a Riga plate, thermal radiation, the Darcy--Forchheimer model, and Casson fluid characteristics. The Riga plate, comprising magnets and electrodes, generates a Lorentz force influenced by the fluid's vertical electrical conductivity. Similarity transformations convert the governing partial differential equations into ordinary differential equations, which are numerically solved using MATLAB's bvp4c sol... More >