Article
Mechanics
Dehao Xu, Jianchun Wang, Changping Yu, Shiyi Chen
Summary: In this paper, an artificial-neural-network-based (ANN-based) nonlinear algebraic model, called MANA model, is proposed for the large-eddy simulation (LES) of compressible wall-bounded turbulence. The model incorporates innovative modifications to the invariants and tensor bases, and utilizes local grid widths to normalize the flow variable gradients. The MANA model outperforms traditional eddy-viscosity models in terms of correlation coefficients, relative errors, and accuracy of predicting flow statistics and mean subgrid-scale fluxes in both a priori and a posteriori tests.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Ming Yu, Chunxiao Xu
Summary: In this study, predictive models for near-wall velocity and temperature fluctuations in compressible wall-bounded turbulence are developed based on the model proposed by Marusic et al. The models incorporate the effects of large-scale motions in the outer region on near-wall turbulence and are validated through direct numerical simulations. The results show good agreement between the predicted fluctuations and the actual results.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Luca Guastoni, Alejandro Guemes, Andrea Ianiro, Stefano Discetti, Philipp Schlatter, Hossein Azizpour, Ricardo Vinuesa
Summary: Two convolutional neural network models were trained to predict velocity-fluctuation fields in turbulent open-channel flow, with one directly predicting fluctuations and the other reconstructing flow fields using a linear combination of orthonormal basis functions. Both models outperformed traditional methods in predicting nonlinear interactions in the flow.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Xi Chen, Katepalli R. Sreenivasan
Summary: The dominant paradigm in turbulent wall flows, stating that the mean velocity near the wall is independent of the friction Reynolds number, has been challenged in recent research. This study presents a promising perspective supported by data, suggesting that fluctuations displaying non-zero wall values or near-wall peaks are bounded for large friction Reynolds numbers due to the natural constraint of bounded dissipation rate.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Bjoern List, Li-Wei Chen, Nils Thuerey
Summary: In this paper, turbulence models trained by convolutional neural networks are proposed to improve low-resolution solutions of the incompressible Navier-Stokes equations. A differentiable numerical solver is developed to support optimization gradients propagation through multiple solver steps, and the importance of this property is demonstrated. Loss terms based on turbulence physics are introduced to enhance model accuracy. The proposed method achieves significant improvements in long-term a posteriori statistics compared to no-model simulations, and also outperforms purely numerical methods in terms of performance.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Chang Liu, Dennice F. Gayme
Summary: The structured-singular-value-based approach proposed in this paper preserves certain input-output properties of the nonlinear forcing function to recover a larger range of key flow features. This method not only identifies flow structures predicted by traditional approaches but also captures oblique turbulent bands that have been observed in experiments and DNS.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
C. Chen, L. He
Summary: Recent findings on wall-bounded turbulence have led to the development of a new modelling method to capture the influence of large-scale coherent structures and scale-interaction on near-wall turbulence. This paper presents a two-scale approach to simulate this influence and validates its effectiveness.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Constantinos Katsamis, Tim Craft, Hector Iacovides, Juan C. Uribe
Summary: This study numerically investigates the performance of different turbulence models in predicting natural convection flows, and finds that a new analytical wall function can improve the accuracy of predictions.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2022)
Article
Mechanics
Yu Lv, Xinyi L. D. Huang, Xiaolei Yang, Xiang I. A. Yang
Summary: The paper addresses performance issues of wall-modeled large-eddy simulation (WMLES) by integrating wall models into LES solvers, abandoning stand-alone wall-model solvers. By employing physics-inspired bases for LES solution reconstruction in the wall-adjacent cell, the computational framework effortlessly accounts for non-equilibrium effects in high-order codes, with channel flow for proof of concept and periodic hill for validation.
Article
Multidisciplinary Sciences
Gregory L. Eyink, Samvit Kumar, Hao Quan
Summary: This article discusses the Onsager theory of wall-bounded turbulence, analyzing the momentum dissipation anomaly hypothesized by Taylor. By performing a coarse-graining operation, the article derives an upper bound on wall friction and establishes a deterministic relationship between the turbulent drag law and the profile of the mean streamwise velocity.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Computer Science, Interdisciplinary Applications
Sergio Pirozzoli, Paolo Orlandi
Summary: This paper proposes a new DNS method for wall-bounded flows, using numerical simulations to derive optimal parameters and grid spacing, and providing a specific prescription for the number of grid points and grid clustering needed for accurate results. The conclusions are supported by high Reynolds number DNS, demonstrating the presence of a near logarithmic layer in the mean velocity profile.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
Feng Xie, Jose D. Perez-Munoz, Ning Qin, Pierre Ricco
Summary: A turbulent drag-reduction method utilizing synthetic jet sheets was investigated through direct numerical simulations. By adjusting the angle and height of the jet sheets, a drag reduction of 10% to 30% was achieved. The study also found that the global skin-friction drag reduction was a result of a finite counter flow induced by the interaction between the jet-sheet flow and the main flow.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Parisa Mirbod, Seyedmehdi Abtahi, Abbas Moradi Bilondi, Marco Edoardo Rosti, Luca Brandt
Summary: This study investigates turbulent suspension flows of non-Brownian, non-colloidal, neutrally buoyant and rigid spherical particles in a Newtonian fluid over porous media. The results show that the presence of particles in the free-flow region affects the mean velocity and concentration profiles due to variations in slip velocity and wall-normal fluctuations at the suspension-porous interface. The stress condition at the interface significantly influences the particle near-wall dynamics and migration towards the channel core, leading to large modulations of the overall flow drag.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Stephan F. Oehler, Simon J. Illingworth
Summary: The study examines linear feedback flow control of the largest scales in an incompressible turbulent channel flow at a friction Reynolds number of Re-tau = 2000. It is found that a control set-up with a well-placed array of sensors and actuators performs comparably to either measuring the flow everywhere or actuating the flow everywhere, providing insight into estimating and controlling the very large scales of turbulence effectively at low computational cost.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2021)
Article
Mechanics
Martin Lellep, Jonathan Prexl, Bruno Eckhardt, Moritz Linkmann
Summary: Machine Learning is increasingly used in fluid dynamics, but algorithms like neural networks are difficult to interpret. The SHAP algorithm, based on game theory, helps explain the output of ML models in fluid dynamics and provides useful insights. It shows that features like laminar profiles, vortices, and streak instabilities play a major role in predictions, helping understand the dynamics of fluid systems.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Mechanical
Ananth Sivaramakrishnan Malathi, Massimiliano Nardini, Aditya Vaid, Nagabhushana Rao Vadlamani, Richard D. Sandberg
Summary: Transitional boundary layers on low-pressure turbines (LPTs) can experience separation on the suction surface of the blade due to adverse pressure gradients. However, intermittent freestream turbulence, periodic wakes, and surface roughness can suppress the separation and reduce profile loss. This study investigates the use of surface roughness in the transitional regime and riblets in the turbulent regime to further decrease losses.
JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME
(2023)
Article
Engineering, Mechanical
John Leggett, Yaomin Zhao, Richard D. Sandberg
Summary: This study investigates the impact of unsteady flow on high-pressure turbines, particularly the effects of wakes from an upstream stator and freestream turbulence. The research shows that changing the characteristics of freestream turbulence directly affects the unsteady behavior of the stator wakes, leading to significant performance changes in the rotor. Additionally, the study reveals that the blade boundary layers on the pressure and suction sides of the rotor respond differently to external disturbances.
JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME
(2023)
Article
Engineering, Aerospace
Sivaramakrishnan Malathi Ananth, Aditya Vaid, Nagabhushana Rao Vadlamani, Massimiliano Nardini, Melissa Kozul, Richard D. Sandberg
Summary: Several high-resolution scale-resolving simulations are conducted to investigate the influence of riblets on the mean and turbulent statistics of a zero-pressure-gradient boundary layer. It is found that riblets can effectively reduce the viscous drag in the turbulent regime, and V-shaped riblets with sharp tips have slightly better performance than curved riblets. In the transitional flow regime, the coherent structures over riblets are predominantly spanwise oriented, and a leading-edge ramp is shown to minimize the additional spurt in the turbulent kinetic energy caused by the abrupt surface change.
Article
Computer Science, Interdisciplinary Applications
Tony Zahtila, Wilson Lu, Leon Chan, Andrew Ooi
Summary: In this paper, direct numerical simulation of fully developed turbulent channel flow is carried out at low Reynolds number to investigate the effect of grid refinement on turbulence statistics in a spectral element method context. The findings show that discontinuity at shared nodes between adjacent spectral elements creates potential artefacts in the averaged statistical quantities. Grid convergence is fast for spatially-averaged terms, particularly for statistics of primitive variables, but may require additional grid resolution for derivative terms. Statistical convergence with grid refinement occurs more quickly in the near-wall region than in the outer region.
COMPUTERS & FLUIDS
(2023)
Article
Hematology
Nurul A. Zainal Abidin, Mariia Timofeeva, Crispin Szydzik, Farzan Akbaridoust, Chitrarth Lav, Ivan Marusic, Arnan Mitchell, Justin R. Hamilton, Andrew S. H. Ooi, Warwick S. Nesbitt
Summary: Researchers have developed a microfluidic assay to study platelet mechanotransduction in the absence of surface adhesions. They found that platelets are highly sensitive to extensional strain rates and respond to the rate of change in strain. The actin-based cytoskeleton and microtubules play a key role in platelet mechanotransduction under extensional strain.
RESEARCH AND PRACTICE IN THROMBOSIS AND HAEMOSTASIS
(2023)
Article
Engineering, Aerospace
Yuan Fang, Yaomin Zhao, Fabian Waschkowski, Andrew S. H. Ooi, Richard D. Sandberg
Summary: In order to improve the predictive accuracy of data-driven models for a wider range of cases, an extension of a computational fluid dynamics (CFD)-driven training framework is proposed. This framework consists of three key steps, including selecting candidate flow-related parameters, modeling an additional production term, and performing Reynolds-averaged Navier-Stokes (RANS) evaluations on multiple different flows simultaneously during model training iterations. The results show that the machine-learned models from this multicase CFD-driven framework can significantly improve the prediction accuracy for test cases with significant errors from the baseline RANS results.
Article
Engineering, Aerospace
Daniel J. Fritsch, Vidya Vishwanathan, Christopher J. Roy, K. Todd Lowe, William J. Devenport, Paul Croaker, Oksana Tkachenko, David Pook, Graeme Lane, Shubham Shubham, Richard D. Sandberg
Summary: This paper presents and evaluates a wide range of models and methods for predicting the surface pressure spectrum beneath turbulent boundary layers. The current state of empirical and analytical pressure spectrum models is thoroughly reviewed, and predictions of different types of pressure gradient boundary layers are examined using a steady Reynolds-averaged Navier-Stokes (RANS) prediction. Existing empirical models show limitations in adapting to pressure gradient conditions or being overly sensitive to inputs. New empirical models are developed using a gene expression programming machine-learning algorithm based on experimental and RANS inputs. The accuracy and robustness of the developed models are improved compared to existing models.
Article
Thermodynamics
Thomas O. Jelly, Massimiliano Nardini, Marco Rosenzweig, John Leggett, Ivan Marusic, Richard D. Sandberg
Summary: This study investigates the impact of blade surface roughness on the aero-thermal performance of a high-pressure turbine vane using highly-resolved Large-Eddy Simulations. The study reveals that blade surface roughness affects boundary layer transition mechanisms, wall shear stress, blade surface heat flux, and turbulence kinetic energy and total pressure losses in the wake. However, the pressure-side surface of the blade remains relatively unaffected, even for the largest roughness amplitude.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Thermodynamics
Minghang Li, Shahram Karami, Richard Sandberg, Julio Soria, Andrew Ooi
Summary: This study investigates the physics of impingement heat transfer in under-expanded supersonic impinging jets using wall-resolved large-eddy simulations. It is found that the impinging jets exhibit a strong oscillation of a stand-off shock, resulting in two peaks of the mean heat transfer coefficients.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Thermodynamics
Chitrarth Lav, Andrew J. Banko, Fabian Waschkowski, Yaomin Zhao, Christopher J. Elkins, John K. Eaton, Richard D. Sandberg
Summary: Recent improvements in turbulence modeling have led to the increasing use of machine-learning algorithms. In this study, tensor basis neural networks (TBNNs) and gene-expression programming (GEP) algorithms are combined to develop interpretable Reynolds stress closures. The high-fidelity Reynolds stress representations obtained from deep-learning are used to learn symbolic expressions for the closures. The results show that using TBNN predictions to inform GEP produces closures with similar accuracy to those developed solely from high-fidelity data, and better prediction accuracy can be achieved when using TBNN predictions for GEP closures compared to using a high-fidelity database comprising multiple flows.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Mechanics
Yitong Fan, Weipeng Li, Richard D. Sandberg
Summary: The study examines the ability of low-rank approximation in hypersonic turbulent boundary layers with and without wall cooling using the compressible form of the linear resolvent operator. The results reveal a relatively subsonic and supersonic region in the optimal response mode in the wave-parameter space, divided by the freestream relative Mach number of unity. The study also investigates the energy distribution, energy spectra, and coherent structures in the optimal response mode, highlighting the effects of wall cooling.
Article
Biology
Mariia Timofeeva, Chitrarth Lav, Michael M. H. Cheung, Andrew Ooi
Summary: In this study, the effect of varying conduit stenosis on the hemodynamics in a surrogate TCPC model was investigated using high-fidelity numerical simulations. The results showed that the flow in the TCPC model exhibited pronounced unsteadiness, and the presence of stenosis amplified the chaotic nature of the flow. Furthermore, it was found that respiration added perturbations to the flow, leading to increased power loss.
COMPUTERS IN BIOLOGY AND MEDICINE
(2023)
Article
Chemistry, Physical
Hualin Zhan, Richard Sandberg, Fan Feng, Qinghua Liang, Ke Xie, Lianhai Zu, Dan Li, Jefferson Zhe Liu
Summary: Machine learning can be used to establish a physics-based nanocircuit model, allowing for the prediction and evaluation of electrical characteristics in nanoporous ionic systems. This approach provides insights into ion dynamics in nanoporous electrodes, such as nonideal cyclic voltammetry and dynamic, pore-size-dependent surface conductance.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Acoustics
S. J. Zhu, A. Ooi, A. Skvortsov, R. Manasseh
Summary: Bubbles can reduce underwater noise propagation through density and acoustic-impedance mismatches, reflection and absorption of sound waves, and bubble-acoustic resonances. A discrete bubble model (DBM) was developed to simulate the noise mitigation effect of bubble curtains. The DBM accurately predicted the resonance frequencies of bubbles in different configurations, and showed that reducing the inter-bubble spacing lowered the collective resonance frequency. Realistic cylindrical bubble curtain configurations with a diameter of 5 m and gas volume fraction values of 1% and 2% were able to reduce broadband acoustic pulse levels by approximately 17 dB. Variations in bubble size significantly impacted curtain performance, while variations in inter-bubble spacing had no significant effect.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
