Exploring binary chemical reaction effects on unsteady MHD quadratic-radiative flow of tri-hybrid nanofluid over a shrinking-rotating Riga disk with multiple solutions
{"title":"Exploring binary chemical reaction effects on unsteady MHD quadratic-radiative flow of tri-hybrid nanofluid over a shrinking-rotating Riga disk with multiple solutions","authors":"Gopinath Mandal , Dulal Pal","doi":"10.1016/j.molliq.2025.128556","DOIUrl":null,"url":null,"abstract":"<div><div>The present work investigates the influence of a binary chemical reaction incorporating activation energy and quadratic thermal radiation on the unsteady three-dimensional flow of a <span><math><mi>M</mi><mi>o</mi><msub><mi>S</mi><mn>2</mn></msub><mo>−</mo><mi>S</mi><mi>i</mi><msub><mi>O</mi><mn>2</mn></msub><mo>−</mo><mi>G</mi><mi>O</mi></math></span>/<span><math><msub><mi>H</mi><mn>2</mn></msub><mi>O</mi></math></span> tri-hybrid nanofluid past a rotating and shrinking Riga disk under the effects of an intense magnetic field and viscous dissipation. The main objective is to examine how the inclusion of nanoparticles in the unsteady tri-hybrid nanofluid alters heat and mass transfer properties, while the rotating–shrinking Riga disk regulates the fluid flow dynamics. Through similarity transformations, the partial differential equations are reduced to ordinary differential equations and numerically solved using MATLAB’s bvp4c solver. The analysis reveals multiple solution branches, with stability assessments confirming that the upper branch is stable having a positive minimum eigenvalue, whereas the second solution produces a negative eigenvalue, showing its instability. The effects of various flow parameters on velocity, temperature, concentration, radial skin-friction coefficient, azimuthal skin-friction coefficient, Nusselt number, Sherwood number and entropy generation are examined through comprehensive numerical simulations. The results indicate that higher nanoparticle volume fractions enhance temperature and binary chemical reaction reduces concentration profiles positively. The quadratic thermal radiation parameter induces system cooling, while the unsteadiness parameter contributes to heating. A significant increase (35.09 %) in radial skin friction is observed, with a 9 % rise in the Modified Hartmann number. Quadratic radiation, nanoparticle volume fraction, and suction effects strongly influence entropy generation over the Riga disk. This research is motivated by its applications in energy-related industries and engineering, particularly in improving heat transfer in rotating machinery, such as gas turbine rotors, renewable thermal systems, and air purification technologies.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"438 ","pages":"Article 128556"},"PeriodicalIF":5.2000,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Liquids","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167732225017337","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
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Abstract
The present work investigates the influence of a binary chemical reaction incorporating activation energy and quadratic thermal radiation on the unsteady three-dimensional flow of a / tri-hybrid nanofluid past a rotating and shrinking Riga disk under the effects of an intense magnetic field and viscous dissipation. The main objective is to examine how the inclusion of nanoparticles in the unsteady tri-hybrid nanofluid alters heat and mass transfer properties, while the rotating–shrinking Riga disk regulates the fluid flow dynamics. Through similarity transformations, the partial differential equations are reduced to ordinary differential equations and numerically solved using MATLAB’s bvp4c solver. The analysis reveals multiple solution branches, with stability assessments confirming that the upper branch is stable having a positive minimum eigenvalue, whereas the second solution produces a negative eigenvalue, showing its instability. The effects of various flow parameters on velocity, temperature, concentration, radial skin-friction coefficient, azimuthal skin-friction coefficient, Nusselt number, Sherwood number and entropy generation are examined through comprehensive numerical simulations. The results indicate that higher nanoparticle volume fractions enhance temperature and binary chemical reaction reduces concentration profiles positively. The quadratic thermal radiation parameter induces system cooling, while the unsteadiness parameter contributes to heating. A significant increase (35.09 %) in radial skin friction is observed, with a 9 % rise in the Modified Hartmann number. Quadratic radiation, nanoparticle volume fraction, and suction effects strongly influence entropy generation over the Riga disk. This research is motivated by its applications in energy-related industries and engineering, particularly in improving heat transfer in rotating machinery, such as gas turbine rotors, renewable thermal systems, and air purification technologies.
期刊介绍:
The journal includes papers in the following areas:
– Simple organic liquids and mixtures
– Ionic liquids
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Experimental studies, computer simulations (MD or MC) and analytical theory will be considered for publication; papers just reporting experimental results that do not contribute to the understanding of the fundamentals of molecular and ionic liquids will not be accepted. Only papers of a non-routine nature and advancing the field will be considered for publication.