Dynamics of Atmospheres and Oceans最新文献

{"title":"Nonlinear analysis of thermo-magneto slip flow of Jeffery fluid in a wavy curved channel","authors":"Maham Mujahid ,&nbsp;Mounirah Areshi ,&nbsp;Zaheer Abbas ,&nbsp;Muhammad Yousuf Rafiq ,&nbsp;Ibrahim E. Elseesy","doi":"10.1016/j.dynatmoce.2025.101633","DOIUrl":"10.1016/j.dynatmoce.2025.101633","url":null,"abstract":"<div><div>This study conducts an analytical examination of thermo-magneto-hydrodynamic slip flow of a Jeffery fluid through a porous wavy curved channel. The energy equation incorporates the effects of thermal radiation along with heat generation and absorption mechanisms. By formulating the governing equations in curvilinear coordinates and applying a regular perturbation method, closed-form expressions for the velocity, temperature, skin-friction coefficient, and Nusselt number are obtained. The parametric investigation indicates that both channel curvature and porous permeability enhance fluid transport, while the applied magnetic field suppresses motion. Thermal radiation notably intensifies heat transfer and facilitates bolus formation by decreasing the effective viscosity and augmenting buoyancy effects. Overall, the findings provide a useful theoretical basis for the design and optimization of advanced thermal management systems, polymer processing technologies, and MHD-based biomedical devices where non-Newtonian and radiative influences are significant.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101633"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatio-temporal dynamics of drought using the remote-sensed data and Google Earth Engine (GEE) in the semi-arid region of India","authors":"Arijit Ghosh ,&nbsp;Azizur Rahman Siddiqui","doi":"10.1016/j.dynatmoce.2025.101641","DOIUrl":"10.1016/j.dynatmoce.2025.101641","url":null,"abstract":"<div><div>Droughts are a significant environmental hazard that disrupts the global hydrological and ecological balance. The Bundelkhand region of the Indian subcontinent is vulnerable to drought. Therefore, the principal objectives of this study are i) to recognize the severity and frequency of drought occurrences and ii) to estimate the spatial extension of drought during diverse seasons in a semi-arid region of India. The Standardized Precipitation Index (SPI) is measured using long-term NASA Power precipitation data. Cloud-based platforms have been applied to process large datasets competently, access real-time information, and improve drought predictions. Vegetation Condition Index (VCI) has been measured using Google Earth Engine (GEE) to recognize the intensity and magnitude of drought hazards. The result indicates that 2001 and 2003 were the driest years in the MP Bundelkhand (-2.23) and UP Bundelkhand (-1.73). In addition, the Banda district of UP experienced a total of 127 drought months (moderate, severe, and extreme drought), followed by Lalitpur (113) and Panna (116). Furthermore, in post-monsoon, the highest VHI value was 74.23, and the lowest was 17.23. The winter season has experienced severe drought (2000–2023), whereas other seasons have experienced moderate droughts. It is prominent that in the case of drought measurement, mean value estimation is possible by using cloud-based real-time data analysis. However, this comprehensive study will be beneficial for future researchers and policymakers to measure the drought in India and around the globe.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101641"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of the boundary layer assumption for mixed convection nanofluid flow over a parabolic surface","authors":"T. Salahuddin ,&nbsp;Ahitsham Akram ,&nbsp;Muhammad Awais ,&nbsp;Mair Khan ,&nbsp;Eatedal Alabdulkreem ,&nbsp;Farkhod Rakhmonov","doi":"10.1016/j.dynatmoce.2025.101639","DOIUrl":"10.1016/j.dynatmoce.2025.101639","url":null,"abstract":"<div><div>In this paper, the numerical analysis is performed on two-dimensional incompressible and natural convection flow of viscous nanofluid by considering the effects of heat generation and porous medium. For this purpose, is regarded as nanoparticles dispersed in some base fluids, including water, methanol, and engine oil. Essentially, the goal of this work is to examine the flow characteristics and thermal performance of three distinct nanofluids. The objective of this study is to measure the effects of thermophysical interactions, porous drag, and nanoparticle loading on heat transmission and irreversibility. Several assumptions are used to develop the flow model. With the appropriate transformation, the two-dimensional non-linear partial differential equations become non-linear ordinary differential equations. In MATLAB software, the Bvp4c technique is utilized to find the numerical outcomes of the flow model. The graphs are modelled by plotting several parameters against the velocity and temperature profiles. The impacts of skin friction and the Nusselt number are assessed for several involved parameters. To investigate the energy loss, the entropy generation model is also assumed. The velocity field marks the incrementing impact due to the thermal Grashof number. By producing the values of the porous media parameter, resulting in the velocity field of the nanofluid methanol + <span><math><mrow><mi>T</mi><msub><mrow><mi>i</mi></mrow><mrow><mn>6</mn></mrow></msub><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>4</mn></mrow></msub><mi>v</mi></mrow></math></span> being very low. We noted that the methanol + <span><math><mrow><mi>T</mi><msub><mrow><mi>i</mi></mrow><mrow><mn>6</mn></mrow></msub><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>4</mn></mrow></msub><mi>v</mi></mrow></math></span> has an extremely low velocity field when the porous medium parameter is big. When the curvature parameter is increased, the temperature field for engine oil rises swiftly in relation to the volume fraction and for water + <span><math><mrow><mi>T</mi><msub><mrow><mi>i</mi></mrow><mrow><mn>6</mn></mrow></msub><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>4</mn></mrow></msub><mi>v</mi></mrow></math></span> nanofluid.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101639"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavior of magneto-viscoelastic fluid flow through a permeable medium with heat source/sink using hybrid methodology","authors":"P.P. Nayak ,&nbsp;S.R. Mishra ,&nbsp;Subhajit Panda","doi":"10.1016/j.dynatmoce.2025.101620","DOIUrl":"10.1016/j.dynatmoce.2025.101620","url":null,"abstract":"<div><div>Viscoelastic fluids change their rheological properties in response to an applied electric or magnetic field. In particular, applications in vehicle damping systems, vibration control devices, shock absorbers, and smart materials for structural engineering the role of viscoelastic fluid is vital. Therefore, the proposed study investigates the influence of magnetized viscoelastic fluid through a permeable medium due to the interaction of a heat source/sink. The free convection with radiative heat transfer characterizes the transport properties significantly. The relevant similarity rules are adopted for the transmutation of the governing phenomena into ordinary as well as dimensionless. Further, the complexity of the flow phenomena impulses to the implementation of perturbation technique to reduce the order of the problem, and then a numerical method such as shooting combined with Runge-Kutta fourth-order contributes to solving the system. Graphs are used to illustrate the characteristics of physical parameters that contribute to the flow phenomena. However, the analysis ended with important flow behaviour described briefly in the conclusion. The study reveals that the heat transfer shows dual behavior with magnetic and radiation effects, being stronger in permeable media. Magnetization reduces shear and mass transfer, while buoyancy boosts velocity. Radiation and chemical reactions influence temperature rise and concentration drop, respectively.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101620"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145625414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of ENSO on the genesis potential index of cyclones over the Bay of Bengal during the post-monsoon season","authors":"P. Suneeta ,&nbsp;TVS Udaya Bhaskar ,&nbsp;S.S.V.S. Ramakrishna","doi":"10.1016/j.dynatmoce.2025.101642","DOIUrl":"10.1016/j.dynatmoce.2025.101642","url":null,"abstract":"<div><div>Tropical Cyclones (TCs) are among the most destructive weather phenomena, causing substantial damage to coastal regions and vulnerable communities along the Bay of Bengal. Predicting their formation remains a significant challenge due to the complex interactions between atmospheric and oceanic processes. This study investigates the influence of the El Niño–Southern Oscillation (ENSO) on the Genesis Potential Index (GPI) and the Total Number of Depressions and Cyclones (TNDC) over the Bay of Bengal (5°–20°N, 80°–100°E) during the post-monsoon season (October–December) from 1995 to 2019. Cyclone activity associated with El Niño, La Niña, and Neutral ENSO phases is examined using four GPI formulations based on key atmospheric and oceanic parameters, including a newly developed index from our previous research. The results reveal pronounced ENSO-dependent variations in vertical wind shear, Upper Ocean Heat Content (UOHC), depth of the 26 °C isotherm (D26), Sea Surface Temperature (SST), Sea Surface Height Anomaly (SSHA), latent heat flux, net longwave radiation, and low-level relative vorticity. During La Niña years, reduced vertical wind shear, enhanced low-level cyclonic vorticity, deeper thermocline, higher UOHC, and increased air–sea heat fluxes create a dynamically and thermodynamically favorable environment for cyclone genesis<strong>,</strong> leading to GPI values nearly twice those observed during El Niño and Neutral phases. These findings demonstrate the critical role of ENSO-driven atmospheric–oceanic coupling in modulating cyclone genesis over the Bay of Bengal and highlight the importance of incorporating ENSO-related variability into regional cyclone forecasting and disaster risk management strategies.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101642"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boundary layer interaction of immiscible non-Newtonian nanofluids in distinct shear flows with motile microorganisms","authors":"Z. Abbas,&nbsp;S. Goher,&nbsp;M.Y. Rafiq","doi":"10.1016/j.dynatmoce.2025.101629","DOIUrl":"10.1016/j.dynatmoce.2025.101629","url":null,"abstract":"<div><div>This study presents a comprehensive numerical investigation of two-phase boundary layer shear flows involving immiscible non-Newtonian Carreau and Tangent hyperbolic nanofluids incorporating motile microorganisms. The analysis explores the coupled effects of thermophoresis, Brownian motion, and thermal radiation on velocity, temperature, concentration, and microorganism density profiles across distinct shear regions. Incorporating microorganisms within nanofluids enhances thermal conductivity and stabilizes the flow structure, contributing to improved transport phenomena relevant to biomedical, energy, and environmental systems. The governing nonlinear differential equations are transformed into dimensionless form using similarity transformations and solved via the MATLAB bvp4c collocation method to ensure high numerical accuracy. A grid independence test confirms the convergence and stability of the scheme for all parametric variations. The results demonstrate that the Carreau fluid parameter promotes fluid velocity, while an increase in the viscosity ratio and shear strength ratio reduces it. Brownian motion and thermophoresis parameters suppress temperature near the interface, whereas thermal radiation enhances it. The density of motile microorganisms rises with higher bioconvection and Péclet numbers but decreases with increasing microorganism Schmidt number. Quantitative results for skin friction, Nusselt number, Sherwood number, and microorganism density validate the influence of these parameters in both regions. The findings provide valuable insights for optimizing microfluidic transport, bioconvective systems, and nanofluid-based heat exchangers where multi-phase shear interactions and microorganism activity are significant.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101629"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of heat and mass transfer in an electromagnetically driven ionized tri-hybrid nanofluids flow over a convectively heated cylinder","authors":"Muhammad Naveed Khan ,&nbsp;Shafiq Ahmad ,&nbsp;Aamir Abbas Khan ,&nbsp;Mounirah Areshi ,&nbsp;Ibrahim E. Elseesy","doi":"10.1016/j.dynatmoce.2025.101635","DOIUrl":"10.1016/j.dynatmoce.2025.101635","url":null,"abstract":"<div><div>Nanofluids are employed in various heat transfer and cooling applications because of their enhanced thermal conductivity, making them useful for electronics cooling, solar collectors, and heat exchangers. The current study explores the behavior of a partially ionized Prandtl fluid with three types of nanoparticles as it flows through a convectively heated cylinder under magnetic influence. The purpose of dispersing three different nanoparticles <span><math><mrow><mfenced><mrow><mi>MWCNT</mi><mo>,</mo><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>,</mo><mi>SiC</mi></mrow></mfenced></mrow></math></span> is to increase the functional fluid heat transfer rate. The study looks at how powerful produced magnetic and electric fields affect fluid flow under the supposition that the magnetic Reynolds number is very high. The study analyzes the mass and heat equations while taking into account factors like Joule heating, activation energy, varying thermal conductivity, and changing mass diffusivity. Additionally, the consequences of Joule heating, viscous dissipation, and thermal radiation are appraised when evaluating the disorder in the flow system through entropy generation. Based on these assumptions, differential equations were employed to create the mathematical model. The differential equations are then subjected to similarity variables to become a dimensionless variant of ordinary differential equations. The numerical scheme BVP4C on MATLAB has been used to find the numerical results. The comparison results are found for ternary nanofluid <span><math><mrow><mfenced><mrow><mi>MWCNT</mi><mo>,</mo><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>,</mo><mi>SiC</mi></mrow></mfenced></mrow></math></span> and unary nanofluid <span><math><mrow><mfenced><mrow><mi>A</mi><msub><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></mfenced></mrow></math></span> using graphs. It is observed from the figures that in enhancement in Prandtl first parameter, curvature parameter, Hall and ion slip effect, the fluid motion enhances while the reverse behavior is observed for Hartman number. The fluid temperature surges with stronger estimations of the Dufour number, variable thermal conductivity, and radiation parameter.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101635"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rainfall extremes variability, teleconnections with atmospheric circulation anomalies in the Indian summer monsoon","authors":"Anmol Yadav ,&nbsp;G.P. Singh ,&nbsp;Pradeep Kumar Rai ,&nbsp;Vijay Kumar Soni ,&nbsp;Akhilesh Mishra ,&nbsp;Sonu Kumar","doi":"10.1016/j.dynatmoce.2025.101636","DOIUrl":"10.1016/j.dynatmoce.2025.101636","url":null,"abstract":"<div><div>We investigate the spatiotemporal variability of Indian Summer Monsoon Rainfall (ISMR) and the anomalies in atmospheric circulation and oceanic conditions during June–September (JJAS) from 1981 to 2022. Using multiple data sources (like IMD, NOAA PSL and HadISST), Empirical orthogonal function (EOF), principal component (PCs) coefficient of variation (CV), precipitation concentration index (PCI), composite analysis of atmospheric and oceanic anomalies determines the variability for exploring extreme wet and dry years. Seasonal rainfall is highest over Northeast India and Western Ghats, while the decadal trend shows increased rainfall in July, August, and September. EOF analysis shows that first mode covers central and southern India, whereas the second mode exhibits a dipole pattern over the Gangetic plains and southern regions with 14.9 % and 9.1 % of the total variance. Eight extremely wet and six extremely dry years were also noted. In composite analysis, wherever extreme wet and dry years are found, these modes correspond to distinct Sea Surface Temperature (SST), Sea Level Pressure (SLP) and wind anomalies across oceanic regions. Wet years exhibit positive rainfall anomalies related with warm SST in Indian Ocean and cooler SST in the Niño 3.4 region, accompanied by low SLP anomalies and enhanced south-westerly wind. Dry years are characterized by cooler SST in the Indian Ocean, warmer Nino 3.4, SST, higher SLP, weak winds, and limited moisture transport, which contribute to the reduction in monsoon activity. These findings underscore the significant role of SST, SLP, wind, and vertical motion, vertically integrated moisture flux and soil moisture anomalies influencing ISMR patterns.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101636"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning for sea surface temperature prediction in the Indian Ocean: A comparative study using 1D-CNN, LSTM, 1DCNN-LSTM and attention based 1DCNN-LSTM architectures","authors":"B. Sheela Rani ,&nbsp;D. Sathya Narayanan ,&nbsp;M.B. Salma Jasmine ,&nbsp;N.R. Krishnamoorthy ,&nbsp;M. Roja Raman ,&nbsp;Aneesh A. Lotliker ,&nbsp;Abhisek Chatterjee","doi":"10.1016/j.dynatmoce.2025.101632","DOIUrl":"10.1016/j.dynatmoce.2025.101632","url":null,"abstract":"<div><div>Anthropogenic activities had led to major climate changes, causing the oceans to warm rapidly. Subsequently, there is a need for accurate prediction of sea surface temperature (SST). The dynamic Indian Ocean climate, weather and marine ecology is significantly affected by SST changes. In this study, hourly and daily SST data, specifically from 15 and 7 RAMA stations (1 m deep) respectively, at different parts of Indian Ocean is utilized to forecast SST using four deep learning techniques; 1D Convolutional Neural Network (1D-CNN), Long Short-Term Memory (LSTM) network, 1DCNN-LSTM network and attention based 1DCNN-LSTM Architecture. The SST data obtained from RAMA buoy is trained using a sliding window method and model performance is evaluated based on evaluation matrices like Mean Squared Error (MSE), Root Mean Squared Error (RMSE), and Mean Absolute error (MAE). The results indicated that 1DCNN-LSTM outperforms 1D-CNN and LSTM at most sites, consistently achieving lower MSE, RMSE and MAE. The findings also revealed that in places where SST shifts significantly, the new attention based 1DCNN-LSTM model often competes with or does better than all the other models in MAE. Distinctive physical phenomena like equatorial jets, thermohaline stratification, monsoon, Indian Ocean Bipolar (IOD) and El Niño-Southern Oscillation (ENSO) bring about geographical difference in performance. Hence, the study illustrates how deep learning frameworks make better SST predictions in complex ocean basins and thereby aids in anticipating climate change.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101632"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient mixed convection in coaxial pipes with temperature-dependent variable density","authors":"Bakhtawar Bibi ,&nbsp;Ali B.M. Ali ,&nbsp;Muhammad Ashraf ,&nbsp;Ghulam Rasool ,&nbsp;Muhammad Usman Rashid ,&nbsp;Abduvali Sottarov","doi":"10.1016/j.dynatmoce.2026.101649","DOIUrl":"10.1016/j.dynatmoce.2026.101649","url":null,"abstract":"<div><div>This study investigates the effects of temperature-dependent variable density on mixed convective heat transfer in coaxial pipes. The inner pipe’s surface is stationary and uniformly heated, with flow along its axis, while the outer wall is placed at infinity. A two-dimensional time-dependent flow and temperature field are modeled using coupled nonlinear partial differential equations, solved numerically via the implicit finite difference method. Simulations explore a range of parameters to predict thermal efficiency, steady-state velocity, temperature distribution, dynamic surface shear, and energy shear. Results show that increasing the density variation parameter (m = 0.1, 1.5, 2.0, 2.5) enhances fluid velocity and thermal distribution, peaking at m = 2.5. Energy shear increases with mm, reaching a maximum at m = 0.7, while surface shear remains uniform. These findings provide insights into optimizing thermal performance in coaxial flow systems.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101649"},"PeriodicalIF":2.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}