Article
Thermodynamics
Mahsa Hajialibabaei, M. Ziad Saghir, Ibrahim Dincer, Yusuf Bicer
Summary: This study investigates the impact of changes in the wavy channel heat sink height on cooling performance using numerical and experimental methods. The results suggest that a channel height of 10 mm is effective for cooling electronic equipment.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Ammar Alsabery, Mikhail A. Sheremet, Ali J. Chamkha, Ishak Hashim
Summary: This study focuses on the numerical simulation of turbulent forced convective energy transport inside a curved channel, aiming to improve the heat transfer surface and address the issue of energy transport enhancement. The results show that an increase in the undulations number leads to significant energy carrier condensation.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
Sumit Kumar Mehta, Sukumar Pati
Summary: The hydrothermal characteristics of forced convective laminar flow of water through a channel with a top wavy wall and a flat bottom wall having metallic porous blocks were investigated computationally. The governing equations were solved using a finite element method-based numerical solver. The presence of porous blocks significantly influenced the heat transfer rate. The paper is rated 7 out of 10.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Thermodynamics
Saurav Kumar, Manash Protim Boruah, Sukumar Pati
Summary: The hydrothermal performance of viscoplastic fluid flowing through a backward facing step channel is studied. The Bingham number, Reynolds number, and power law index are analyzed for their effects on thermal and flow characteristics. Results show that an increase in Bingham number leads to a decrease in reattachment length and an increase in temperature drop. The local Nusselt number peaks near the step and increases with Bingham number.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Zuzana Brodnianska, Stanislav Kotsmid
Summary: This paper focuses on specific wavy heat exchange surfaces to enhance convective heat transfer in the channel. It is found that the offset wavy channel achieves higher thermal performance compared to the in-line wavy channel, which increases with Re and decreases with height H. The thermal performance of the offset wavy channel is improved by 5.7%-15.7% when changing Re and H compared with the in-line one.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Chemistry, Physical
Meng Gu, Shirong He, Xiaohui Jiang, Yonggang Wang, Kehui Xiong, Feng Gao, Xi Yang
Summary: A novel composite flow channel was proposed to address issues within the cathode flow channel of proton exchange membrane fuel cells (PEMFCs), including gas transport obstruction, poor water removal performance, high pressure drop, and low current density. By combining a tapered design with a 3D wave structure, the flow channel was able to optimize performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Sumit Kumar Mehta, Sukumar Pati, Shahid Ahmed, Prangan Bhattacharyya, Jishnu Jyoti Bordoloi
Summary: This study aims to analyze the thermal, hydraulic and entropy generation characteristics for laminar flow through a ribbed-wavy channel with different rib geometries. The findings show that the average Nusselt number is higher for ribbed-wavy channels compared to parallel plate channels beyond a critical Reynolds number. Additionally, the performance factor sharply decreases with Reynolds number up to a certain point before either gradually decreasing or increasing, depending on the rib shape and number.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2022)
Article
Thermodynamics
A. Alsabery, A. Hajjar, M. A. Sheremet, M. Ghalambaz, I Hashim
Summary: The analysis focuses on the computational study of nanosuspension forced convection in a horizontal wavy channel with heating from the upper wavy surface. The use of nanofluids and irregular channels can enhance energy transport and heat removal. Increasing Reynolds number leads to a narrowing of fluid tube within the channel and improvement of average velocity and Nusselt number, while higher channel waviness number results in increased average particle velocity and temperature.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Multidisciplinary Sciences
Nima Ghorbani, Mohammad Zabetian Targhi, Mohammad Mahdi Heyhat, Yousef Alihosseini
Summary: A numerical study was conducted to investigate the ability of wavy microchannels in dampening temperature fluctuations in electronic devices. The results showed that wavy patterns with larger amplitude to wavelength ratios have enhanced heat transfer and can be used to improve the thermal-hydraulic performance of heat sinks.
SCIENTIFIC REPORTS
(2022)
Article
Thermodynamics
Zuzana Brodnianska, Stanislav Kotsmid
Summary: This study experimentally and numerically investigated the enhancement of heat transfer and the decrease of pressure drop in a wavy shaped heated channel with cylindrical vortex generators. The holographic interferometry method was used to visualize the temperature distribution, and the Ansys Fluent software was used for the evaluation of temperature, velocity, and pressure fields. The results showed that inserting the cylindrical vortex generators at position 2 of the wavy channel led to the highest thermal performance factor of 0.8167.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Sumit Kumar Mehta, Sukumar Pati, Laszlo Baranyi
Summary: In this study, the hydrothermal characteristics of laminar forced convective flow of water through different types of sinusoidal asymmetric wavy channels were investigated. The results showed that the average Nusselt number was almost independent of the channel geometry for lower Reynolds numbers and slopes. However, at higher Reynolds numbers, the average Nusselt number was highest for the linearly increasing amplitude channel, followed by the linearly decreasing amplitude channel and the constant amplitude channel. The study also evaluated the combined effects of heat transfer increase and associated pumping power in the wavy channel compared to the plane channel.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Lucas Farias Severo, Flavia Schwarz Franceschini Zinani, Luiz Alberto Oliveira Rocha
Summary: This study applies the Constructal Design Method to investigate a row of circular tubes subjected to cross-flows of visco-plastic Bingham fluids, finding that the dimensionless heat transfer density increases with the Bejan number but decreases with the Bingham number. Additionally, the optimal step distance between tubes decreases with the increase in the Bejan number, but increases with the increase in the Bingham number.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Hyun Sik Yoon, Seok Hyun Nam, Min Il Kim
Summary: This study investigates forced convection heat transfer around wavy elliptic cylinders with different aspect ratios and wavelengths. The results show that short wavelengths result in quasi-2D thermal structures, while long wavelengths form 3D thermal structures. The thermal characteristics are influenced by the state of the thermal structures. As the aspect ratio decreases, the streamlined shape becomes predominant in stabilizing forced convection.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Ge-Yu Zhong, Peng-Fan Chen, Fa-Zhu Liu, Ying-Wen Liu
Summary: This study focuses on the unsteady characteristics of heat transfer process in wavy channels under oscillating flow, with findings on the factors influencing heat transfer performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Engineering, Aerospace
Cheng Yao, Yuxue Pu, Zhongming Wang, Yongxin Gao
Summary: Oscillating flow is a challenge for wide-Mach-number-range flight. A 2D wavy surface implemented on the flat-bottomed wall of the Sajben diffuser is found to effectively mitigate the large-amplitude forced shock-wave oscillation. The depth of the wavy surface benefits the mitigation of oscillation amplitudes, while the length of the wavy surface can have varying effects depending on the specific value. The mitigating mechanism is explained from the perspectives of shock-wave stability and work performed by a moving shock-wave. The presence of a transient second shock-wave can be explained by post-shock expansion.
Article
Thermodynamics
Ajit Kumar, Sumit Kumar Mehta, Sukumar Pati, Laszlo Baranyi
Summary: This paper analyzes the heat and momentum transfer for steady two-dimensional incompressible nanofluid flow through a wavy channel with linearly varying amplitude. The results show that the wavy channel has a higher heat transfer rate compared to a plane channel, and the heat transfer rate increases with the nanoparticle volume fraction. The combined effects of heat transfer increase and associated pressure drop in the wavy channel are presented. This study is relevant for applications such as solar collectors, heat exchangers, and heat sinks. It is the first analysis of forced convection flow of nanofluid through a wavy channel with linearly varying amplitude.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Thermodynamics
Abhijit Borah, Sumit Kumar Mehta, Sukumar Pati
Summary: This paper numerically analyzes the forced convective conjugate heat transfer characteristics for laminar flow through a wavy minichannel. The results show that considering the effect of wall thickness in the theoretical model predicts a lower average Nusselt number compared to the case of conjugate analysis. The study also finds that conjugate heat transfer analysis predicts higher performance factor compared to nonconjugate analysis for any geometrical configurations.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Engineering, Electrical & Electronic
Sumit Kumar Mehta, Pranab Kumar Mondal
Summary: In this study, we numerically investigated the convective heat transfer and entropy generation characteristics in a wavy solar power plant filled with MWCNT-Fe3O4-water nanofluid. The presence of a wavy wall and the addition of nano-particles were found to weaken the recirculation in the flow field and increase the average Nusselt number. The increase in wave amplitude and nano-particle volume fraction also reduced the average entropy generation.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2023)
Article
Thermodynamics
T. Sujith, Sumit Kumar Mehta, Sukumar Pati
Summary: In this work, a theoretical model considering the finite size of ions and interfacial slip is developed to study the entropy generation in electroosmotic flow through a rectangular microchannel. The model uses the Navier-slip model and the modified Poisson-Boltzmann equation, and is numerically solved using a finite element method-based solver. The results show that the effect of the finite size of ions on entropy generation depends strongly on the viscous and Joule heating. The average total entropy generation decreases with the slip coefficient and increases with the steric factor for lower thermal Peclet number (Pe), while the opposite effect is observed at higher Pe values.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Biochemical Research Methods
Sumit Kumar Mehta, Pranab Kumar Mondal
Summary: We propose a new micromixer design by inserting a two-part cylinder bearing zeta potential in the upstream and downstream directions. A vortex is developed in the flow pathway due to the substantial momentum difference between the microchannel's wall and cylinder, enhancing mixing efficiency. The shear-induced aggregation characteristic time sharply increases with increasing shear-thinning behavior of the fluid.
Article
Thermodynamics
Sumit Kumar Mehta, Sukumar Pati
Summary: The hydrothermal characteristics of forced convective laminar flow of water through a channel with a top wavy wall and a flat bottom wall having metallic porous blocks were investigated computationally. The governing equations were solved using a finite element method-based numerical solver. The presence of porous blocks significantly influenced the heat transfer rate. The paper is rated 7 out of 10.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Engineering, Mechanical
Daniel Dorogi, Efstathios Konstantinidis, Laszlo E. Kollar, Laszlo Baranyi
Summary: The purpose of this study is to develop a reduced-order model (ROM) for predicting the vortex-induced vibration of an elastically mounted circular cylinder. The results showed that acceleration forcing can predict the amplitude response well, whereas velocity forcing leads to underestimation. The ROM can accurately predict the magnitude of the total streamwise force and the wake drag, but not the frequency response trend. Both acceleration and velocity forcing can predict the phase lag between the wake drag and the cylinder displacement well.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Engineering, Mechanical
Daniel Dorogi, Laszlo Baranyi, Efstathios Konstantinidis
Summary: The response of a spring-mounted circular cylinder constrained to vibrate with a single degree of freedom transverse to an oscillating stream is investigated using twodimensional flow simulations. The results show that the cylinder undergoes intermittent vortex-induced vibration with amplitude modulations at the end of the flow acceleration stage. Pronounced hysteresis is observed in the plots of the ensemble-averaged amplitude and frequency, and it is related to the 'transient' operating points that join smoothly the distinct branches of steady-VIV. The stochastic features become more pronounced as the frequency ratio increases.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Sumit Kumar Mehta, Pranab Kumar Mondal
Summary: This study explores the potential of the AC electrothermal (ACET) effect in enhancing the mixing of electrolytic liquids in a novel wavy micromixer. Numerical simulations are used to investigate the temperature rise, flow topology, species concentration field, and mixing efficiency in the micromixer. The results show that the ACET effect leads to a maximum temperature increase of less than 10 K in the micromixer and significantly influences the mixing efficiency. This research provides a foundation for the design of microfluidic devices for improved solute mixing in practical applications.
Article
Chemistry, Multidisciplinary
Sumit Kumar Mehta, Ayush Rathour Raj, Pranab Kumar Mondal
Summary: By varying the pH values and types of salt solution, the salinity gradient-induced electrical and mechanical flow energies inside a reservoir-connected charged nanochannel with a grafted pH-sensitive polyelectrolyte layer were investigated. The results showed that the PEL space charge density decreased with increasing pH at lower values, and the electrical conductance and maximum pore power were higher for the Co(en)(3)Cl-3 solution compared to other salts. It was also found that the maximum electrical energy conversion efficiency increased with pH, reaching its highest level for the Co(en)(3)Cl-3 solution.
Article
Engineering, Electrical & Electronic
Sumit Kumar Mehta, Dhananjay Kumar, Pranab Kumar Mondal, Somchai Wongwises
Summary: We investigated the thermo-hydraulic characteristics of heat flow in a solar power plant with wavy channel and porous blocks, considering the thermal dispersion effect. The flow field inside the porous blocks was modeled using the Darcy-Brinkman-Forchheimer equations and solved numerically. By changing the thermal dispersion coefficient, Reynolds number, and Darcy number, we examined the temperature field, conductive heat flux, local Nusselt number, average Nusselt number, and performance factor. Our findings showed that thermal dispersion decreased the average temperature and increased the conductive heat flux near the bottom wall close to porous blocks. The increase in average Nusselt number and performance factor was higher at higher Reynolds numbers, but underestimated when ignoring the conjugate heat transfer effect.
MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS
(2023)
Article
Mechanics
Sumit Kumar Mehta, Pranab Kumar Mondal
Summary: This study investigates the viscoelectric effect and concentration-gradient-driven chemiosmotic flow in a charged soft nanochannel. The results show that the viscoelectric effect significantly increases the viscosity near the wall, while pH values and solute concentrations have a minor impact. The average flow velocity exhibits an increasing-decreasing pattern with an increase in solute concentration in the right-side reservoir, and this decrease in flow velocity becomes more pronounced with higher solute concentrations when considering the viscoelectric effect.
Article
Mechanics
Dhananjay Kumar, Sumit Kumar Mehta, Pranab Kumar Mondal
Summary: We investigate the mixing of soft biofluids in a narrow fluidic device under the influence of electroosmotic vortices generated by patterned soft polyelectrolyte layers (PEL). The interplay between fluid rheology and geometrical parameters of PEL significantly affects the size and strength of vortices, which then modulate the mixing strength. We demonstrate that higher shear-thinning behavior of components and larger extent of PEL structure enhance solute mixing (>90%).
Article
Mechanics
Sumit Kumar Mehta, Rahul Kakati, Ayaz Rahman, Pranab Kumar Mondal, Somchai Wongwises
Summary: This study numerically analyzes the impact of electroosmotic vortex and fluid rheology on the chemical reaction characteristics of species, focusing on biochemical applications and relevant physical properties. The results show that the formation of vortices in the microreactor enhances the ability of reactant species to react, increasing convective mixing strength. Additionally, the fluid rheology significantly affects the reaction characteristics.
