ASME journal of heat and mass transfer最新文献

{"title":"Atmospheric Bubbling Fluidized Bed Risers: Effect of Cone Angle on Fluid Dynamics and Heat Transfer","authors":"H. J. Das, P. Mahanta","doi":"10.1115/1.4066182","DOIUrl":"https://doi.org/10.1115/1.4066182","url":null,"abstract":"\u0000 In this paper, a comparative study of fluid dynamics and thermal characteristics of sand particles has been carried out numerically and experimentally in bubbling fluidized bed risers for five-cone angles of the riser wall having 0°, 5°, 10°, 15° and 20°. An Eulerian model with a k-e turbulence model is used to explore the numerical analysis, and the findings are compared to those of the experiments. For the study, the inlet air velocity is fixed at 1.5 m/s with sand particles filled up to 30 cm to maintain bubbling conditions in the risers. The results indicate that when the cone angle increases while maintaining the amount of bed materials constant, there is a corresponding reduction in pressure drop. The expansion of particles along the riser is observed to decrease with an increase in cone angle. The radial solid volume fraction profile transforms to a U shape from the W-type profile as the cone angle increases. Correspondingly, the solid velocity is found to have an inverted U-type and W-shaped profile for the risers. The granular temperature is also found to increase with a decrease in the solid percentage at any location. The average bed temperature, interphase, and bed-to-wall heat transfer coefficient at a location of 10 cm axial height also increase with the cone angle. As a result, the conical riser, when designed with a greater cone angle, exhibits more efficiency in terms of heat transfer characteristics.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141927850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytic Modelling of 2-D Transient Heat Conduction with Heat Source Under Mixed Boundary Constraints by Symplectic Superposition","authors":"Dian Xu, Jinbao Li, Zixuan Wang, Sijun Xiong, Qianqiang He, Rui Li","doi":"10.1115/1.4066031","DOIUrl":"https://doi.org/10.1115/1.4066031","url":null,"abstract":"\u0000 Many studies have been conducted on 2-D transient heat conduction, but analytic modelling is still uncommon for the cases with complex boundary constraints due to the mathematical challenge. With an unusual symplectic superposition method, this paper reports new analytic solutions to 2-D isotropic transient heat conduction problems with heat source over a rectangular region under mixed boundary constraints at an edge. With the Laplace transform, the Hamiltonian governing equation is derived. The applicable mathematical treatments, e.g., the variable separation and the symplectic eigenvector expansion in the symplectic space, are implemented for the fundamental solutions whose superposition yields the ultimate solutions. Benchmark results obtained by the present method are tabulated, with verification by the finite element solutions. Instead of the conventional Euclidean space, the present symplectic-space solution framework has the superiority on rigorous derivations without pre-determining solution forms, which may be extended to more issues with the complexity caused by mixed boundary constraints.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141814845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melting Behavior Effect of MXene Nanoenhanced Phase Change Material on Energy and Exergyanalysis of Double and Triplex Tube Latent Heat Thermal Energy Storage","authors":"Utkarsh Srivastava, Rashmi Sahoo","doi":"10.1115/1.4065997","DOIUrl":"https://doi.org/10.1115/1.4065997","url":null,"abstract":"\u0000 The impacts of melting behaviour on the thermal performance of TT-TES and DT-TES systems employing cetyl alcohol and 3% v/v. MXene nanoenhanced PCM are compared and numerically evaluated in this work. For both the DT-TES and TT-TES systems, the following were investigated in connection to melting time: system efficiency, discharged energy, heat transfer rate, exergy destruction, entropy generation number, exergetic efficiency, melting fraction, and melting temperature contours. In addition, the effect of Stefan, Rayleigh, and Nusselt numbers on Fourier numbers are compared for the DT-TES and TT-TES systems with MXene NEPCM.\u0000 MXene-based nano-enhanced PCM melting in TT-TES displayed 6.53% more Stefan number than cetyl alcohol. Pure melting of MXene-based nano-enhanced PCM in a TT-TES had 4.16% higher storage exergy than cetyl alcohol. The entropy generation number of pure melting of MXene-based nano-enhanced PCM in TT-TES is 7.93% lower than that of cetyl alcohol. Pure cetyl alcohol has 76.99% optimal system efficiency at 5400 seconds melting time and MXene NEPCM 77.04% at 4800 seconds in DT-TES. The charging temperature for pure cetyl alcohol PCM in TT-TES is 0.7% lower than in DT-TES. Furthermore, pure melting of MXene-based nano-enhanced PCM in a TT-TES has 1.95% lower storage energy than cetyl alcohol. For a given volume of MXene-based nano-enhanced cetyl alcohol PCM, melting occurs more rapidly in a TT-TES system.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Evaluation of the Film Cooling Characteristics of the Multi-cavity Tip with Inclined Film Holes","authors":"Zhe Jia, Feng Li, Weixin Zhang, Zhao Liu, Zhenping Feng","doi":"10.1115/1.4065515","DOIUrl":"https://doi.org/10.1115/1.4065515","url":null,"abstract":"\u0000 Due to the complex flow field and the considerable heat load on the turbine blade tip, film cooling is essential to protect the tip from being overheated. In this paper, an experimental work was conducted to compare the film cooling distributions of four tip structures (cavity numbers are one, two, three, and four) with two film hole configurations (perpendicular and 45 degrees inclined to the cavity floor) under three coolant blowing ratios. By using pressure sensitive paint technique, the distributions of film cooling effectiveness were measured. Moreover, a computation with careful validation was executed to obtain the cooling traces in the tip region and compare the aerodynamic performance of these multi-cavity tips. The results showed that the value and uniformity of film cooling effectiveness were improved by the inclined configuration. The tip film cooling was enhanced when using the multi-cavity tips. The aerodynamic loss of the tested tips was compared as well.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140970230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of Short-Time Heat Conduction Solutions in One-Dimensional Finite Rectangular Bodies","authors":"Filippo de Monte, K. Woodbury, Hamidreza Najafi","doi":"10.1115/1.4065449","DOIUrl":"https://doi.org/10.1115/1.4065449","url":null,"abstract":"\u0000 The concept of both penetration and deviation times for rectangular coordinates along with the principle of superposition for linear problems allow short-time solutions to be constructed for a one-dimensional rectangular finite body from the well-known solutions of a semi-infinite medium. Some adequate physical considerations due to thermal symmetries with respect to the middle plane of a slab to simulate homogeneous boundary conditions of the first and second kinds are also needed. These solutions can be applied at the level of accuracy desired (one part in 10A, with A = 2, 3, …, 15) with respect to the maximum temperature variation (that always occurs at the active surface and at the time of interest) in place of the exact analytical solution to the problem of interest.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141011090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experiments On Gasketed Plate Heat Exchangers with Segmented Corrugation Pattern","authors":"Matheus Strobel, L. Beckedorff, Giovani Martins, J. Oliveira, K. Paiva","doi":"10.1115/1.4065453","DOIUrl":"https://doi.org/10.1115/1.4065453","url":null,"abstract":"\u0000 Gasket plate heat exchanger (GPHE) is among the most used heat exchanger types, known for its high effectiveness and compact design. Its remarkable feature is the corrugated plate geometry, typically a Chevron pattern. This work aims to analyze another corrugation pattern, which has segments with different angles to the vertical. The strengths and weaknesses of the segmented plate are still unclear, as the studies on this pattern are scarce. To fill this gap, we experimentally assess the pressure drop and heat transfer in a GPHE composed of 31 segmented plates. The plates have four quadrants, and the combination of low-angle and high-angle plates can form up to six channel types. Pressure and temperature data are acquired in 144 sets of experiments. In the pressure drop results, we observe a considerable discrepancy between the two streams, which leads to a discussion of a relevant phenomenon: the elastic deformation of the plates. If the inner pressure of the streams is not equal, the pressure gradient causes the plates to deform and change the channel geometry. The stream with the higher pressure has its channels expanded, while the lower pressure channels will be strangled. This phenomenon is rarely reported in the literature and strongly affects the pressure drop. Moreover, we present friction factor correlations for six channel types using flow data. Based on the generalized Lévêque analogy in the heat transfer experiments, we argue that the plates' deformation also affects the heat transfer.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Algorithm as the Solution of Non-Linear Inverse Heat Conduction Problems: a Novel Sequential Approach","authors":"Dominic Allard, Hamidreza Najafi","doi":"10.1115/1.4065452","DOIUrl":"https://doi.org/10.1115/1.4065452","url":null,"abstract":"\u0000 Direct measurement of surface heat flux could be extremely challenging, or impossible, in numerous applications. In such cases, the use of temperature measurement data from sub-surface locations can facilitate the determination of surface heat flux and temperature through the solution of the inverse heat conduction problem (IHCP). Different techniques have been developed for solving IHCPs. Inspired by the filter coefficient approach, a novel method is presented in this paper for solving one-dimensional IHCPs in a domain with temperature-dependent material properties. A test case is developed in COMSOL Multiphysics where the front side of a slab is subject to known transient heat flux and the temperature distributions within the domain are calculated. The IHCP solution in the form of filter coefficients is defined and a genetic algorithm is used for the calculation of filter matrix. The number of significant filter coefficients required to evaluate surface heat flux at each time step is determined through trial and error and the optimal number is selected for evaluating the solution. The structure of the filter matrix is assessed and discussed. The resulting filter coefficients are used to evaluate the surface heat flux for several cases and the performance of the proposed approach is assessed in detail. The results showed that the presented approach is robust and can result in finding optimal filter coefficients to accurately estimate various types of surface heat flux profiles using temperature data from a limited number of time steps and in a near real-time fashion.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141009920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of Multiple Contact Conductances in a Silicon-Indium-Silicon Stack","authors":"K. Woodbury, Grant Cutler, Hamidreza Najafi, Maya Kota","doi":"10.1115/1.4065448","DOIUrl":"https://doi.org/10.1115/1.4065448","url":null,"abstract":"\u0000 This report documents evaluation of simultaneous estimation of multiple interfacial heat transfer coefficients (HTCs) using transient measurements from an experiment designed for steady-state operation. The design of a mirror system for directing x-rays under cryogenic conditions requires knowledge of the interfacial HTC (contact conductance) between silicon and indium. An experimental apparatus was constructed to measure temperatures in a stack of five 7.62 mm thick pucks of silicon separated by 0.1 mm thick sheets of indium which is operated under cryogenic temperatures in vacuum. Multiple pucks and interfaces are incorporated into the apparatus to allow evaluation of HTCs for surfaces of different roughness from a single experiment. Analysis of the sensitivity of each of the measured temperatures to each of the unknown HTCs reveals lack of linear independence of these sensitivities and suggests the recovery of the HTCs will be challenging. Artificially noised “data” were created from two different computational models by solving for temperatures and adding random Gaussian noise with a specified standard deviation. These data are subsequently analyzed using two different iterative parameter estimation methods: a Levenberg scheme and a Tikhonov iterative scheme. The required sensitivity matrix is computed using forward finite difference approximations. The results for the heat transfer coefficients for this model problem suggest that coefficients cannot be estimated independently, but the ratios relative to one of the unknowns can be recovered.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141008558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryogenic Air Supply Feasibility for a Confined Space: Underground Refuge Alternative Case Study.","authors":"Lincan Yan, Dave S Yantek, Cory R DeGennaro, Justin R Srednicki, Brandin Lambie, Jacob Carr","doi":"10.1115/1.4064062","DOIUrl":"10.1115/1.4064062","url":null,"abstract":"<p><p>A breathable air source is required for a confined space such as an underground refuge alternative (RA) when it is occupied. To minimize the risk of suffocation, federal regulations require that mechanisms be provided and procedures be included so that, within the refuge alternative, the oxygen concentration is maintained at levels between 18.5% and 23% for 96 h. The regulation also requires that, during use of the RA, the concentration of carbon dioxide should not exceed 1%, and the concentration of carbon monoxide should not exceed 25 ppm. The National Institute for Occupational Safety and Health (NIOSH) evaluated the cryogenic air supply's ability to provide breathable air for a refuge alternative. A propane smoker was used to simulate human breathing by burning propane gas which will consume O₂ and generate CO₂ and H₂O. The rate of propane burned at the smoker was controlled to represent the O₂ consumption rate for the breathing of a certain number of people. Two 96-h tests were conducted in a sealed shipping container, which was used as a surrogate for a refuge alternative. While burning propane gas to simulate human oxygen consumption, cryogenic air was provided to the shipping container to determine if the cryogenic air supply would keep the O₂ level above 18.5% and CO₂ level below 1% inside the shipping container as required by the federal regulations pertaining to refuge alternatives. Both of the 96-h tests simulated the breathing of 21 persons. The first test used the oxygen consumption rate (1.32 cu ft of pure oxygen per hour per person) specified in federal regulations, while the second test used the oxygen consumption rate specified by (Bernard et al. 2018, \"Estimation of Metabolic Heat Input for Refuge Alternative Thermal Testing and Simulation,\" Min. Eng., <b>70</b>(8), pp. 50-54) (0.67 cu ft of pure oxygen per hour per person). The test data shows that during both 96-h tests, the oxygen level was maintained within a 21-23% range, and the CO₂ level was maintained below 1% (0.2-0.45%). The information in this paper could be useful when applying a cryogenic air supply as a breathable air source for an underground refuge alternative or other confined space. [DOI: 10.1115/1.4064062].</p>","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10755670/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139072466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Buoyancy and Velocity Field Synergy Principle in Convective Heat Transfer and its Role in Thermo-Hydraulic Performance Improvement","authors":"Dong Yang, Xinyue Hu, Feilong Chen, Yingli Liu","doi":"10.1115/1.4064734","DOIUrl":"https://doi.org/10.1115/1.4064734","url":null,"abstract":"\u0000 This study proposes the buoyancy and velocity field synergy principle and aims to enhance thermo-hydraulic performance in convective heat transfer. A mechanical energy conservation equation concerning synergy between buoyancy and velocity was derived, which describes the mechanical energy transport and dissipation in convective heat transfer. Two new field synergy numbers, Fsu,g and Fsu,p, were proposed to characterize the degree of synergy between velocity and buoyancy, and the degree of synergy between velocity and pressure gradient over the fluid domain, respectively. The pressure drop of a channel subjected to convective heat transfer is related to not only Gr/Re2 but also Fsu,g. Under a same Gr/Re2, a larger | Fsu,g | leads to a smaller | Fsu,p |, and thus the pressure drop is decreased. Furthermore, the multi-field synergetic relationships among buoyancy, velocity, temperature gradient and pressure gradient were analyzed for convective heat transfer in channels. The correlation between Fsu,p and Fsu,g *Gr/Re2, and the correlation between Fsu,g and a traditional field synergy number characterizing convective heat transfer capability, Fc, were derived, which reveals the coupled mechanisms of mechanical energy dissipation and thermal energy transport. The proposed principle was applied in typical channel flows subjected to convective heat transfer, and its benefits were demonstrated. It is noted that both pressure drop reduction and convective heat transfer enhancement can be achieved in using the proposed principle. This paper provides a new insight for improving thermo-hydraulic performance of heat exchangers.","PeriodicalId":510895,"journal":{"name":"ASME journal of heat and mass transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139781618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}