Electroosmotic Flow Research Articles

Optimizing electrokinetic remediation for pollutant removal and electroosmosis/dewatering using lateral anode configurations

Soil electrokinetics (SEK) research has been widely used in various fields such as soil remediation, dewatering, land restoration, geophysics, sedimentation, pollution prevention, consolidation, and seed germination. According to our most recent published research on SEK process design modifications during the last 30 years (1993–2022), more than 150 designs have been introduced to assure SEK’s maximum performance. Incorporating lateral electrodes/anodes was not documented in the existing literature, which motivated us to investigate the output of this design. In this study, we aimed to enhance the performance of the perforated cathode pipe soil electrokinetic remediation (SEKR) system (PCPSS) for removing inorganic pollutants by installing lateral anodes (LA-PCPSS) using two approaches. In the first approach, the LA-PCPSS was connected to different sources of applied voltages (DSAV) from different power supplies, while in the second approach, the entire operation system was connected to the same source of applied voltage (SSAV). We used the Taguchi approach (L9OA) to determine the optimal levels of applied voltages for the DSAV system. The results indicated that the DSAV-(LA-PCPSS) could be optimized at an applied voltage of 1 V cm−1 for the surface and the first and second lateral anodes. The indigenous Sr (elements found in the tested soil without artificial pollution) in kaolinite showed the best response among other elements (Ni and other indigenous elements) when optimizing the DSAV-(LA-PCPSS) using the Taguchi approach. Installing lateral anodes (position B) supplied to low applied voltage (0.5 V cm−1) improved the electroosmosis (EO) rate/dewatering. Reverse migration of ions was observed during the remediation of real contaminated soil using the SSAV-(LA-PCPSS). The DSAV-(LA-PCPSS) is considered an appropriate design for the SEKR of inorganic pollutants, and increases the EO flow/dewatering. Additionally, the increased energy consumption employing the DSAV-(LA-PCPSS) was extremely minimal compared to the traditional PCPSS, which is an economic advantage for SEKR research. The DSAV-(LA-PCPSS) is still under optimization/intensification process, and subsequent processes will be examined to achieve high efficiency.

Controlled Translocation of Proteins through a Biological Nanopore for Single-Protein Fingerprint Identification.

After the successful sequencing of nucleic acids, nanopore technology has now been applied to proteins. Recently, it has been demonstrated that an electro-osmotic flow can be used to induce the transport of unraveled polypeptides across nanopores. Polypeptide translocation, however, is too fast for accurate reading its amino acid compositions. Here, we show that the introduction of hydrophobic residues into the lumen of the nanopore reduces the protein translocation speed. Importantly, the introduction of a tyrosine at the entry of the nanopore and an isoleucine at the entry of the β-barrel of the nanopore reduced the speed of translocation to ∼10 amino acids/millisecond while keeping a relatively large ionic current, a crucial component for protein identification. These nanopores showed unique features within their current signatures, which may pave the way toward protein fingerprinting using nanopores.

Heat and mass transfer analysis of s-PTT nanofluid in microchannels under combined electroosmotic and pressure-driven flows with wall slip using the homotopy perturbation method

The heat and mass transfer of the electroosmotic flow in microchannel transporting viscoelastic nanofluid is investigated considering Brownian motion of nanoparticles and slip boundary conditions. The simplified Phan-Thien-Tanner model is employed to describe the rheological behavior of fluid and the nonlinear Navier model with non-zero slip critical shear stress is considered at walls. The governing nonlinear momentum, mass, and heat transfer equations are solved using the Homotopy Perturbation Method. The study reveals that increasing the fluid elasticity, nanoparticle concentration, and size significantly enhances the flow rate, heat and mass transfer. Additionally, elasticity and Reynolds number decrease the friction factor. Reducing the double-layer thickness and increasing the Reynolds number lead to higher flow rates and fluid velocities. Notably, the findings emphasize the critical role of the slip conditions on the Sherwood and Nusselt numbers.

Electroosmotic peristaltic transport of magnetohydrodynamic Casson nanofluid in a non-uniform wavy porous asymmetric micro-channel

Magnetohydrodynamics (MHD) have numerous engineering and biomedical applications such as sensors, MHD pumps, magnetic medications, MRI, cancer therapy, astronomy, cosmology, earthquakes, and cardiovascular devices. In view of these applications and current developments, we investigate the magnetohydrodynamic MHD electro-osmotic flow of Casson nanofluid during peristaltic movement in a non-uniform porous asymmetric channel. The effect of thermal radiation, heat source, and Hall current on the Casson fluid peristaltic pumping in a porous medium is taken into consideration. The effect of chemical reactions is also considered. The mass, momentum, energy, and concentration equations were constructed using the proper transformations and dimensionless variables to make them easier for non-Newtonian fluids. A lubricating strategy is used to make the system less complicated. The Boltzmann distribution of electric potential over an electric double layer is studied using the Debye–Huckel approximation. The temperature and concentration equations are addressed using the homotopy perturbation method (HPM), while the exact solution is determined for the velocity field. The study examines the performance of velocity, pressure rise, temperature, concentration, streamlines, Nusselt, and Sherwood numbers for the involved parameters using graphical illustrations and tables. Asymmetric channels exhibit varying behavior, with velocity declining near the left wall and accelerating towards the right wall while enhancing the Casson fluid parameter. The pumping rate boosts in the retrograde region due to the evolution of the permeability parameter value, while it declines in the augment region. The temperature profile optimizes as the value of the heat source parameter gets higher. The concentration profile significantly falls as the chemical reaction parameter rises. The size of the trapped bolus strengthens with a spike in the parameter for the Casson fluid.

A perspective on guided electrophoretic transport of particles in liquid crystals

Nonlinear electrophoresis in complex fluids like nematic liquid crystals provides new pathways toward achieving precisely controlled motion and assembly of microscopic objects. The nematic host introduces a paradigm shift in the mechanism of electrophoretic transport by generating unbalanced electro-osmotic flows around the colloidal particle due to symmetry breaking of the medium caused by the induced topological defects. Rationally designed particles, which induce various types of defects and asymmetries, provide new opportunities in this regard. In this Perspective article, we discuss how the asymmetry in the shape and interfacial properties help in piloting the particles using an AC electric field. Finally, we propose some feasible strategies to achieve navigational control using magnetic and photo-responsive particles, guided by orthogonal electric, magnetic fields, and light, respectively.

Simulation study on mitigating permeate flux decline with electroosmotic flux in dead-end ultrafiltration process

Piezoelectric membranes establish electrokinetic phenomena, including electroosmotic flow, to mitigate membrane fouling in the ultrafiltration process. This study employs numerical simulations to evaluate the role and impact of the electroosmotic flux effect on permeate flux decline and fouling mechanisms in the dead-end filtration process for silicon dioxide particles. This research demonstrates that electroosmotic flux significantly alleviates flux decline across varying values of surface zeta potential, membrane porosity, particle size and inlet concentration. Specifically, the electroosmotic flux effect is most pronounced in reducing flux decline when the surface zeta potential is higher and the membrane structure is more porous. This reduction in flux decline is attributed to the enhanced lift and drag forces generated by electroosmotic flux near the electrical double layer, which prevents rapid initial adhesion and subsequent fouling, such as internal blocking and cake layer formation. Additionally, the electroosmotic flux effect is most effective with smaller particle sizes and higher feed concentrations, helping to mitigate flux decline that would otherwise occur in the absence of electroosmotic flux. Compared to experimental and modelling investigations, the electroosmotic flux effect is shown to complement a reduction in permeate flux drop to facilitate the longevity of membranes in the ultrafiltration process.

DC Electric Fields Promote Biodegradation of Waterborne Naphthalene in Biofilter Systems.

Biofiltration is a simple and low-cost method for the cleanup of contaminated water. However, the reduced availability of dissolved chemicals to surface-attached degrader bacteria may limit its efficient use at certain hydraulic loadings. When a direct current (DC) electric field is applied to an immersed packed bed, it invokes electrokinetic processes, such as electroosmotic water flow (EOF). EOF is a surface-charge-induced plug-flow-shaped movement of pore fluids. It acts at a nanometer distance above surfaces and allows the change of microscale pressure-driven flow profiles and, hence, the availability of dissolved contaminants to microbial degraders. In laboratory percolation columns, we assessed the effects of a weak DC electric field (E = 0.5 V·cm-1) on the biodegradation of waterborne naphthalene (NAH) by surface-attached Pseudomonas fluorescens LP6a. To vary NAH bioavailability, we used different NAH concentrations (C0 = 2.7, 5.1, or 7.8 × 10-5 mol·L-1) and Darcy velocities typical for biofiltration ( = 0.2-1.2 × 10-4 m·s-1). In DC-free controls, we observed higher specific degradation rates (qc) at higher NAH concentrations. The qc depended on , suggesting bioavailability restrictions depending on the hydraulic residence times. DC fields consistently increased qc and resulted in linearly increasing benefits up to 55% with rising hydraulic loadings relative to controls. We explain these biodegradation benefits by EOF-altered microscale flow profiles allowing for better NAH provision to bacteria attached to the collectors even though the EOF was calculated to be 100-800 times smaller than bulk water flow. Our data suggest that electrokinetic approaches may give rise to future technical applications that allow regulating biodegradation, for example, in response to fluctuating hydraulic loadings.

Electro-osmotic flow instability of viscoelastic fluids in a nanochannel

The study of the complex rheological properties of viscoelastic fluids in nanochannels will facilitate the application of nanofluidics in biomedical and other fields. However, the flow of viscoelastic fluids in nanochannels has significant instabilities, and numerical simulation failures are prone to occur at high Weissenberg numbers (Wi). In this study, the simplified Phan-Thien-Tanner viscoelastic fluid model is solved using the log-conformation tensor approach, and the effects of rheological parameters of the viscoelastic fluid, such as the Weissenberg number (Wi), extensibility parameter (ε), and viscosity ratio (β), on the flow characteristics and flow instability within the nanochannel are investigated. The results indicate that the variation of rheological parameters of viscoelastic fluids has a significant effect on the flow state and flow instability of fluids in nanochannels. When the rheological parameters are in a specific range, the flow velocity and outlet current in the nanochannel exhibit relatively regular periodic fluctuations. As the flow transitions from an up-and-down moving single-vortex state to a symmetric double-vortex state, the average velocity of the central axis in the nanochannel is increased by about 15%. Furthermore, when Wi increases from 150 to 400, the length and height of the vortex increase by 50% and 100%, respectively.

Effect of charge inversion on the electrokinetic transport of nanoconfined multivalent ionic solutions

Understanding the effects of phenomena occurring at electrically charged interfaces, such as charge inversion (CI), is crucial for enabling electroosmosis as an efficient transport mechanism in nanodevices. Here, we employ molecular dynamics (MD) simulations to systematically analyze the effect of CI on the electrokinetic transport of multivalent ionic solutions confined in amorphous silica nanochannels. We employ mixtures of monovalent and multivalent counterions while fixing the total ionic concentration to establish correlations between observed phenomena and the amount of multivalent ionic species in the electrolyte solution. The results show that the development of CI is related to a decrease in the mobility of the fluid layers adjacent to the charged surface. In addition, we observe that interfacial overcharging disrupts the water molecular orientation in the fluid layers adjacent to the channel walls. From the non-equilibrium MD simulations of electro-osmotic flow, we disclose the influence of phenomena related to the presence of CI. In particular, flow reversal occurs in scenarios involving CI due to increased local viscosity and a higher concentration of coions within the hydrodynamically mobile and electrokinetically active region of the charged interface. We also find that the magnitude of the wall zeta (ζ) potential displays a monotonic increase with the development of CI in the system. Moreover, we explain why positioning the wall ζ potential at an imaginary (slip) plane, which separates the hydrodynamically mobile and immobile fluid, is misleading.

Protein Denaturation Inspired Microchannel-based Electrochemiluminescence Sensor for Formaldehyde Detection

Establishing an effective system to measure formaldehyde (HCHO) content in food is of great significance due to food safety concern. Inspired by the mechanism of HCHO-induced protein denaturation and its effect on ion/molecule transport in nanochannels, a bioinspired microchannel-based electrochemiluminescence (ECL) sensor was constructed for HCHO detection. Benefiting from the water solubility of HCHO, the molecules rapidly spread and enriched at the ethylenediamine (EDA) functionalized microchannel interface. The reaction between EDA and HCHO significantly increased the negative charge density, leading to enhanced electroosmotic flow (EOF). This enhancement resulted in ion concentration depletion at the microchannel tip and a corresponding decrease in ionic current and ECL intensity. The ECL intensity exhibited a linear dependence on the logarithm of HCHO concentration ranging from 1 pg mL-1 to 100 ng mL-1, with a detection limit of 0.26 pg mL-1(S/N=3). The biosensor demonstrated high selectivity, successfully detecting HCHO in shrimp samples. The performance of the bioinspired sensor was confirmed through comparation with existing methods, showcasing its superior sensitivity and reliability. The bioinspired sensor provides robust technical support for HCHO detection, crucial for food safety monitoring. Additionally, the innovative combination of bionics and microchannel-based ECL technology broadens the application range of ECL sensors, marking a significant advancement in the field.

Preparation of DNA nanoflower-modified capillary silica monoliths for chiral separation.

Innovative chiral capillary silica monoliths (CSMs) were developed based on DNA nanoflowers (DNFs). Baseline separation of enantiomers such as atenolol, tyrosine, histidine, and nefopam was achieved by using DNF-modified CSMs, and the obtained resolution value was higher than 1.78. To further explore the effect of DNFs on enantioseparation, different types of chiral columns including DNA strand containing the complementary sequence of the template (DCT)-modified CSMs, DNF2-modified CSMs, and DNF3-modified CSMs were prepared as well. It was observed that DNF-modified CSMs displayed better chiral separation ability compared with DCT-based columns. The intra-day and inter-day repeatability of model analytes' retention time and resolution kept desirable relative standard deviation values of less than 8.28%. DNF2/DNF3-modified CSMs were able to achieve baseline separation of atenolol, propranolol, 2'-deoxyadenosine, and nefopam enantiomers. Molecular docking simulations were performed to investigate enantioselectivity mechanisms of DNA sequences for enantiomers. To indicate the successful construction of DNFs and DNF-modified CSMs, various charaterization approaches including scanning electron microscopy, agarose gel electrophoresis, dynamic light scattering analysis, electroosmotic flow, and Fourier-transform infrared spectroscopy were utilized. Moreover, the enantioseparation performance of DNF-modified CSMs was characterized in terms of sample volume, applied voltage, and buffer concentration. This work paves the way to applying DNF-based capillary electrochromatography microsystems for chiral separation.

A comprehensive analysis of the advantages and disadvantages of pulsed electric fields during soil electrokinetic remediation

AbstractSoil electrokinetic remediation (SEKR) is considered an effective method for removing pollutants by integrating chemical, physical, and biological treatments. It has multiple applications in fields such as dewatering, consolidation, sedimentation, seed germination, etc. This work builds upon a series of recent publications on SEKR, covering topics like electrode approaches, reverse polarity-based SEK, SEK design modifications, installation of perforated materials, and chemical-based SEK. This review focuses on the role of pulsed electric field (PEF) in enhancing the performance of SEKR. There are several other names for the PEF, including periodic, interval, “ON” and “OFF”, intermittent, and breaking electric fields. PEF is proposed as a solution to overcome certain obstacles in SEKR. The review evaluates PEF's impact on (a) remediating organic and inorganic hazards, anions, and salt, (b) integrating with other processes (reverse polarity, phytoremediation, and bioremediation), and (c) electro-dewatering and consolidation. PEF offers several advantages, such as reducing energy consumption, converting the residual fractions into weakly bound fractions, achieving satisfactory remediation, avoiding the voltage drop in the area across the cation exchange membrane, enhancing desorption and/or migration of charged species, permits the exchange of contaminant from solid to the liquid phase (interstitial fluid), allows contaminant diffusion through the soil pores during the off time, generate high electroosmotic flow, avoiding electrode corrosion, decreasing concentration polarization, etc. However, it may also prolong the remediation period and cause contaminant diffusion through the soil pores, which are considered obstacles for SEKR. This review also describe different techniques related to PEF and highlights the potential use of solar cells as a renewable energy source for SEKR. Graphic abstract

Experimental study of electroosmosis and (Cl-) diffusion in fired-clay bricks

Electroosmosis (EO) is considered as a base for methods in drying moist masonry. EO and the other transport mechanisms, namely electromigration and diffusion, that can influence EO in the bricks, were studied in four Danish bricks with different manufacturing years and locations. Brick cubes were cut from each brick type and then saturated in NaCl 0.1 M solution. A cell with four electrodes was used to measure the electroosmotic permeability coefficient using a phenomenological approach based on non-equilibrium thermodynamics. The effective diffusion coefficient for chloride and electromigration coefficient were calculated. Results showed that the EO flux obtained in the bricks did not follow either the magnitude of zeta potential or ionic content present in the bricks. It was observed that there was a correlation between the EO coefficient and the porous structure of the brick, especially with the pore connectivity, since the bricks with higher pore connectivity and, therefore, with higher effective diffusion coefficient had a higher electroosmotic coefficient.

Enhanced microscale hydrodynamic near-cloaking using electro-osmosis

Abstract In this paper, we develop a general mathematical framework for enhanced hydrodynamic near-cloaking of electro-osmotic flow for more complex shapes, which is obtained by simultaneously perturbing the inner and outer boundaries of the perfect cloaking structure. We first derive the asymptotic expansions of perturbed fields and obtain a first-order coupled system. We then establish the representation formula of the solution to the first-order coupled system using the layer potential techniques. Based on the asymptotic analysis, the enhanced hydrodynamic near-cloaking conditions are derived for the control region with general cross-sectional shape. The conditions reveal the inner relationship between the shapes of the object and the control region. Especially, for the shape of a deformed annulus or confocal ellipses cylinder, the relationship of shapes is quantified more accurately by recursive formulas. Our theoretical findings are validated and supplemented by a variety of numerical results. The results in this paper also provide a mathematical foundation for more complex hydrodynamic cloaking. Additionally, the concept of cloaking has efficient applications in the field of microfluidics, including drag reduction, microfluidic manipulation, and biological tissue coculture.

Mechanism of sinuous and varicose modes in electrokinetic instability.

The flow of miscible electrolyte streams with mismatched electrical conductivities in the presence of a parallel applied electric field is known to exhibit electrokinetic instability (EKI). This paper deals with EKI in a configuration where the base state is established by electro-osmotic flow (EOF) of three coflowing streams, with the center stream having different conductivity than the sheath streams. All reported experiments of this EKI have shown that the instability exhibits either sinuous or varicose modes depending upon whether the center stream has higher or lower conductivity than the sheath streams, respectively. In this paper we elucidate the physical mechanism underlying the selection of these unstable modes in EKI using linear stability analysis. The stability analysis shows that the EOF simply convects the unstable modes besides establishing the base state. The instability occurs due to stationary convection cells, in the reference frame moving with the EOF, resulting from the coupling of the applied electric field with free charge in the regions with conductivity gradients. Importantly, we show that the unstable and stable disturbances for the configuration with a higher conductivity center stream have opposite stability characteristics when the center stream has lower conductivity than the sheath streams. Our analysis correctly explains the numerous experimental observations showing the consistent appearance of sinuous modes for higher conductivity and varicose modes for lower conductivity center streams.

CFD simulation of the interaction between water droplets on the GDL of a low temperature PEM FC in conditions of air cross-flow

Abstract Droplet dynamics in low temperature proton exchange membrane fuel cells (LT-PEMFCs) are significantly important with respect to water management and removal. Three main phenomena are linked to water generation/transport in a LT-PEMFC: H2O production on the cathode side, electro-osmotic drag (anode to cathode) and back diffusion (cathode to anode). The excess/lack of water, depending on membrane humidity, strongly affects LT-PEMFC performance, involving its instability. In this work CFD simulation of droplets was performed when they were deposited in tandem on the gas diffusion layer (GDL) and subjected to 15 m/s parallel air flow. The volume of fluid (VOF) method was adopted and droplets with diameters that range from 0.3 mm to 0.8 mm were considered. Simulations demonstrate that deformations, oscillations and sliding of droplets were affected by their relative size and position. Results can contribute to define predictive models of water droplet dynamics on the GDL surface and their detachment towards the FC gas channel.

On-line enrichment and separation of glycoprotein by capillary electrophoresis based on pH response coating column

A capillary column coated with 3-aminophenylboronic acid (APBA)-functionalized gold nanoparticles (AuNPs@APBA) was prepared via electrostatic self-assembly. The coated column exhibited anti-nonspecific adsorption of glycoproteins, enabling selective online enrichment during capillary electrophoresis (CE). First, gold nanoparticles (AuNPs) were synthesized using the sodium citrate reduction method. Then, APBA was self-assembled electrostatically on the surface of the AuNPs to obtain AuNPs@APBA. This nanomaterial was bonded to the inner wall of a capillary through ion adsorption to produce a AuNPs@APBA-coated capillary column. Glycoproteins were adsorbed via bond formation with boric acid groups under alkaline conditions (pH 8) to generate borate esters. Under acidic conditions (pH 3), the borate esters dissociated to release the glycoproteins, thereby achieving the selective online enrichment and separation of glycoproteins. The AuNPs and AuNPs@APBA were characterized using Fourier transform infrared spectroscopy, and their sizes and Zeta potentials were determined. In addition, the electroosmotic flow (EOF) of the AuNPs@APBA-coated capillary column was measured. The results showed that the surface of the AuNPs was successfully modified with APBA and that AuNPs@APBA was adsorbed on the inner wall of the capillary. The peak area of ovalbumin (OVA) on the AuNPs@APBA-coated column was 26.46 times higher than that on a bare column via conventional electrophoresis. In contrast, the peak area of bovine serum albumin (BSA) only increased by 8.47 times, indicating that the AuNPs@APBA coated column selectively enriched glycoproteins. Evaluation of the reproducibility and stability of this method revealed that the AuNPs@APBA coated capillary column could be used continually for 33-67 h. The relative standard deviations (RSDs) of the peak areas for intra-day (n=5) and inter-day (n=6) analyses were 2.2% and 3.0%, respectively. The developed method was successfully applied to enrich glycoproteins in a 1×106-fold diluted egg white sample. Glycoproteins were not detected using conventional electrophoresis on the bare column, whereas the AuNPs@APBA-coated capillary column effectively enriched and separated glycoproteins, resulting in a peak area of 10469 mAU·ms. Furthermore, the entire enrichment and separation process was completed within 3 min. This new online enrichment and separation method for glycoproteins has the advantages of low sample consumption, simple operation, and high separation efficiency.

Modulating solute transport in magnetohydrodynamic pulsatile electroosmotic micro-channel flow: Role of symmetric and asymmetric wall zeta potentials

Modulating solute transport in magnetohydrodynamic pulsatile electroosmotic micro-channel flow: Role of symmetric and asymmetric wall zeta potentials

Quantitative performance analysis of anion-exchange membrane fuel cells with in-plane and through-plane water transport

Effective water management is crucial in anion-exchange membrane fuel cells (AEMFCs) due to water's dual role as a reactant during alkaline oxygen reduction and a product of alkaline hydroxide oxidation. Meanwhile, both hydroxide conduction and water transport in polymer electrolytes are highly dependent on the hydration level. Therefore, a three-dimensional multi-physics model is developed to investigate the critical role of ionic and water transport parameters of the electrolyte on AEMFC performance. Additionally, detailed water distribution analysis is used to reveal its fundamental mechanism. The results reveal that extremely inhomogeneous water distribution and cathode water starvation are the main causes of the poor cell performance. Moreover, increasing membrane water diffusivity, water conversion, and decreasing the electro-osmotic drag coefficient all contribute to better cell performance through improved water balance and cathode water supply. Among these, cell performance is most sensitive to membrane water diffusivity, with a 40 % increase in peak power density when it is increased from 10−10 m2 s−1 to 10−9 m2 s−1. Although high ionic conductivity improves cell performance by directly reducing ohmic impedance, it also results in a more inhomogeneous distribution of water in the whole cell, so that a four-fold increase in ionic conductivity only yields a 62 % increase in peak power density.

Electromagnetohydrodynamic flow and thermal performance in a rotating rough surface microchannel

Rough surfaces in microchannels effectively enhance liquid mixing, thermal performance, and chemical reactions in electrically actuated microfluidic devices. Rotation of the microchannel with surface roughness intensifies this enhancement. We investigate the combined effects of electromagnetohydrodynamics and surface roughness on transient rotating flow in microchannels. We present a mathematical model considering the variable zeta potential, heat transfer characteristics, and entropy generation within the microchannel. We obtain analytical solutions using the separation of variables method and Fourier series expansion. The surface roughness of the microchannel, when combined with rotation, impacts the temperature enhancement. Higher rotation rates result in the formation of multiple vortices. The secondary flow pushes the primary velocity toward the boundary layer, which affects the flow pattern. Surface roughness and electroosmotic flow significantly affect secondary flow, resulting in complex flow patterns and reversals. The interaction between centrifugal and viscous forces results in maximum velocities at the boundary layers. Higher roughness and electromagnetic effects enhance temperature by intensifying fluid-solid friction and joule heating. Surface roughness causes an increase in wall shear stress and friction factor, resulting in a higher Poiseuille number. Moreover, surface roughness increases entropy production by enhancing fluid mixing and internal friction despite improved heat transfer. Higher rotation also elevates entropy generation due to additional vortices induced by secondary flow.