Heat and Mass Transfer最新文献_第9页

Calculation and analysis of compression and expansion in a piston hybrid power machine with regenerative heat exchange in pump mode 泵工况活塞式蓄热式混合动力机压缩膨胀计算与分析

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-24 DOI: 10.1007/s00231-023-03435-y

V. E. Shcherba

{"title":"Calculation and analysis of compression and expansion in a piston hybrid power machine with regenerative heat exchange in pump mode","authors":"V. E. Shcherba","doi":"10.1007/s00231-023-03435-y","DOIUrl":"https://doi.org/10.1007/s00231-023-03435-y","url":null,"abstract":"Based on the analysis of existing studies on the calculation of the process of compression of a droplet liquid in a displacement pump, we developed a method for assessing the effect of external heat transfer, deformation work and mixing heat transfer on the working fluid heating in the pump. Using the results of a numerical experiment on the increase in pressure and temperature during compression in a positive displacement pump, it was found that the greatest influence on the increase in pressure during compression is by deformation processes (an increase in pressure due to a change in volume ranges from 80 to 92%), then there is mass transfer (pressure increase is from 7 to 16%) and heat exchange, the values of which are about 2.5%. The decisive effect on the working fluid heating in the working chamber of the pump is the conversion of deformation work into heat (from 92 to 95%), the values of external and mixing heat transfer are approximately the same and range from 2.5% to 3.5% each. The nature of the effect of the independent variables used (discharge pressure, crankshaft speed, radial clearance in the cylinder-piston group and the average temperature of the working chamber surface) on each of the components of the relative change in pressure and temperature during the compression process has been established. We established that the crankshaft revolutions has the greatest effect on the relative increase in pressure and temperature during compression, followed by the value of the radial clearance and discharge pressure. The average temperature of the surface of the working chamber has practically no effect on the increase in pressure due to the processes of deformation, mass transfer and heat interaction and only affects the relative change in temperature due to external heat transfer.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138514992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental investigations on novel orientation study on axially grooved heat pipe with two evaporators and one condenser with multiple branches 多支双蒸发器一冷凝器轴向槽热管新定向研究的实验研究

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-23 DOI: 10.1007/s00231-023-03441-0

Anand A. Bhatt, Rajesh N. Patel, Sanjay V. Jain, Dipak V. Vaghela

{"title":"Experimental investigations on novel orientation study on axially grooved heat pipe with two evaporators and one condenser with multiple branches","authors":"Anand A. Bhatt, Rajesh N. Patel, Sanjay V. Jain, Dipak V. Vaghela","doi":"10.1007/s00231-023-03441-0","DOIUrl":"https://doi.org/10.1007/s00231-023-03441-0","url":null,"abstract":"Conventional heat pipes with one evaporator and one condenser are used to cool only one heat source at a time. In electronics and space applications, where a large number of heat sources are to be cooled with limited space available, a multi branch heat pipe could be the solution. In the present study, a heat pipe (T-shape) with three branches was developed with 20 number of axial grooves in which two branches worked as evaporators and one branch as a condenser. Experimental study was performed by considering four novel types of orientations i.e. (a) horizontal orientation (HO) (b) gravity assisted orientation (GAO) (c) anti-gravity orientation (AGO) and (d) compound orientation (CO). The results are analyzed in terms of start-up characteristics and total heat transfer coefficient at different heat loads. Evaporator and condenser thermal resistances are calculated and analyzed for better understanding. It was found that horizontal orientation resulted in the highest overall heat transfer coefficient (2.72 kW/m2 ℃ at 240 W) and comparatively lower evaporator temperatures (less than 100 ℃ at 240 W) which is suitable condition for electronics cooling. Maximum effective thermal conductivity of 31.82 kW/m ℃ was achieved in horizontal orientation. It also resulted in lowest evaporator resistance (0.157 ℃/W) and lowest condenser resistance (0.114 ℃/W). Phenomena of temperature jump was observed and elaborated for compound orientation.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138515007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microstructure and gas–surface interaction of a carbon/carbon composite in atmospheric entry plasmas 大气入口等离子体中碳/碳复合材料的微观结构与气-表面相互作用

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-17 DOI: 10.1007/s00231-023-03428-x

Chen Wang

{"title":"Microstructure and gas–surface interaction of a carbon/carbon composite in atmospheric entry plasmas","authors":"Chen Wang","doi":"10.1007/s00231-023-03428-x","DOIUrl":"https://doi.org/10.1007/s00231-023-03428-x","url":null,"abstract":"The surface roughness features that develop on a three-dimensional (3D) carbon/carbon (C/C) composite during ablation, that is, material loss and morphology distribution on the wall, were investigated, and a microstructure model was established to analyze the flow field characteristics on the C/C composite surface. The model relies on two changes of scale: (i) the multi-wave height (bundle) varies from 50 μm to 110 μm and (ii) the bundle diameter varies from 0.3 mm to 0.5 mm. At each scale, the 2D full Navier–Stokes surface equation was solved numerically to obtain the heat, friction, and pressure in the steady state. Roughness disturbs the flow properties of the boundary layer, creating additional heat flow and aggravating ablation. Numerical results in a hypersonic gas-thermal environment show the distribution characteristics of the coarse-walled heat flow. Thermochemical ablation preserves the roughness profile and wavefront, which changes the distribution of the external flow field. The flow-heat-ablation analogy study can effectively characterize the flow-field distribution characteristics and timely heat and mass transfer responses of materials under rough walls. Innovative microstructure simulation showcases the intrinsic relationship between microstructure roughness, ablativity, and thermal mechanical properties. These intrinsic laws and data can make significant contributions to the design and optimization of thermal protection systems.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138514986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of MLP neural network for modeling effects of electric fields on bubble growth in pool boiling 电场对池沸腾气泡生长影响的MLP神经网络优化

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-16 DOI: 10.1007/s00231-023-03434-z

Mahyar Ghazvini, Seyyed Mojtaba Varedi-Koulaei, Mohammad Hossein Ahmadi, Myeongsub Kim

{"title":"Optimization of MLP neural network for modeling effects of electric fields on bubble growth in pool boiling","authors":"Mahyar Ghazvini, Seyyed Mojtaba Varedi-Koulaei, Mohammad Hossein Ahmadi, Myeongsub Kim","doi":"10.1007/s00231-023-03434-z","DOIUrl":"https://doi.org/10.1007/s00231-023-03434-z","url":null,"abstract":"In this paper, a multilayer perceptron (MLP)-type artificial neural network model with a back-propagation training algorithm is utilized to model the bubble growth and bubble dynamics parameters in nucleate boiling with a non-uniform electric field. The influences of the electric field on different parameters that describe bubble’s behaviors including bubble waiting time, bubble departure frequency, bubble growth time, and bubble departure diameter are considered. This study models single bubble dynamic behaviors of R113 created on a heater in an inconsistent electric field by utilizing a MLP neural network optimized by four different swarm-based optimization algorithms, namely: Salp Swarm Algorithm (SSA), Grey Wolf Optimizer (GWO), Artificial Bee Colony (ABC) algorithm, and Particle Swarm Optimization (PSO). For evaluating the model effectiveness, the MSE value (Mean-Square Error) of the artificial neural network model with various optimization algorithms is measured and compared. The results suggest that the optimal networks in the two-hidden layer and three-hidden layer models for the bubble departure diameter improve MSE by 33.85% and 35.27%, respectively, when compared with the best response in the one-hidden layer model. Additionally, for bubble growth time, the networks with two hidden layers and three hidden layers have the 44.51% and 45.85% reduction in error, when compared with the network with one hidden layer, respectively. For the departure frequency, the error reduction in the two-layer and three-layer networks is 46.85% and 62.32%, respectively. For bubble waiting time, the best networks in the two hidden-layer and three hidden-layer models improve MSE by 52.44% and 62.27% compared with the best 1HL model response, respectively. Also, the two algorithms of SSA and GWO are able to compete well (comparable MSE) with the PSO and ABC algorithms.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138514988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis and experimental validation of a pumped two-phase loop for multi-component electronics cooling 多部件电子冷却泵浦两相回路的分析与实验验证

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-15 DOI: 10.1007/s00231-023-03440-1

Myron Middelhuis, Miguel Muñoz Rojo, Wessel W. Wits

{"title":"Analysis and experimental validation of a pumped two-phase loop for multi-component electronics cooling","authors":"Myron Middelhuis, Miguel Muñoz Rojo, Wessel W. Wits","doi":"10.1007/s00231-023-03440-1","DOIUrl":"https://doi.org/10.1007/s00231-023-03440-1","url":null,"abstract":"Miniaturization and enhanced performance of microchips has resulted in powerful electronic devices with high heat flux components. For these advanced electronics, the current heat transfer method of single-phase forced convection is reaching its thermal limit and more effective cooling solutions are needed. A pumped two-phase loop, in which a pump circulates a working fluid that evaporates to absorb heat, can offer a solution. In this paper the cooling performance of a pumped two-phase loop is discussed and validated. A numerical tool has been developed to aid in designing a fit-for-purpose pumped two-phase loop and to predict its behaviour to changing system parameters and heat inputs. Results from the numerical model are compared with temperature, pressure and flow velocity measurements obtained from a prototype setup. The effects of applying varying heat loads on both a single evaporator and on multiple evaporators simultaneously either in series or in parallel have been investigated. Heat transfer coefficients between 7 and 10 kW/m2K were obtained during the experiments. Model predictions correspond well to the measured performances and findings on the two-phase boiling behaviour are presented. The model is particularly useful for the rapid assessment of the layout of a pumped two-phase loop for high heat flux electronics cooling.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138515009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of dense packed micro-/nano-porous thin film surfaces developed by a combined method of etching, electrochemical deposition and sintering on pool boiling heat transfer performance 采用蚀刻、电化学沉积和烧结相结合的方法制备的致密微/纳米多孔薄膜表面对池沸腾传热性能的影响

IF 2.2 4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-15 DOI: 10.1007/s00231-023-03438-9

Sanjay Kumar Gupta, Rahul Dev Misra

{"title":"Effect of dense packed micro-/nano-porous thin film surfaces developed by a combined method of etching, electrochemical deposition and sintering on pool boiling heat transfer performance","authors":"Sanjay Kumar Gupta, Rahul Dev Misra","doi":"10.1007/s00231-023-03438-9","DOIUrl":"https://doi.org/10.1007/s00231-023-03438-9","url":null,"abstract":"The transportation of quick latent heat during phase change heat transfer (boiling) guides its prospective application in various heat transfer devices. The stability of the fabricated cavity/porous surfaces with the base substrate is a significant concern for the degradation of boiling performance. Therefore, a new three-step surface fabrication method (wet etching, electrochemical deposition, and sintering) is proposed in this work. Initially, the three micro/nanostructured surfaces (ES#3, ES#2, and ES#1) are fabricated by using wet/chemical etching. The best-performing wet/chemical etching surface (ES#3) is further used as a cathode for next-of-surface fabrication, i.e., electrochemical deposition. The electrochemically deposited surface (ES#4) is sintered in a predefined atmosphere to increase the bonding between the coated surface (copper-alumina) and the etching surface (ES#3). The higher boiling performance found on the final surface (ES#4) is due to the proper bonding between the ES#3 and electrodeposited copper-alumina nanoparticles. A decrease in the intermediate resistance due to proper binding boosts the percentage of heat transmission by keeping the temperature constant between the top surface of the heater and the tip of the fin. For ES#4, the critical heat flux (CHF) improvement over bare copper is 98%. Comparing the ES#4 coated surface to the bare copper surface results in a 260% increase in heat transfer coefficient (HTC). The effect of various macro and micro-scale constraints on pool boiling heat transfer phenomena is also investigated. Following multiple testing cycles, the decrease in superheat temperatures, surface morphology, and wettability for ES#4 is significantly lower, which indicates healthier stability of ES#4 surface.","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138515004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of spatially varying thermal contact conductance of non-conformal bolted joint 非保形螺栓连接空间变化接触热导的估计

4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-04 DOI: 10.1007/s00231-023-03436-x

E Kishor, E Ajul, Samarjeet Chanda, Sovan Lal Das

引用次数: 0

Estimation of the thermal properties of MgO-SiO2/water hybrid nanofluid and development of novel thermo-economically viable model for heat transfer applications MgO-SiO2/水混合纳米流体的热性能评估及新型热经济传热模型的开发

4区工程技术

Heat and Mass Transfer Pub Date : 2023-11-02 DOI: 10.1007/s00231-023-03432-1

Vamshi Krishna Poloju, Sayantan Mukherjee, Purna Chandra Mishra, Nawaf F. Aljuwayhel, Naser Ali, Vidyasri Khadanga

引用次数: 0

Experimental investigations on the thermal performance of ultrasonic field in pool boiling on rib surfaces 肋面池沸腾超声场热性能的实验研究