Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods最新文献

Local, Instantaneous Heat Transfer in Pulse-Stabilized Fluidization 脉冲稳定流化中的局部瞬时传热

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0095

D. Pence, D. E. Beasley

{"title":"Local, Instantaneous Heat Transfer in Pulse-Stabilized Fluidization","authors":"D. Pence, D. E. Beasley","doi":"10.1115/imece1996-0095","DOIUrl":"https://doi.org/10.1115/imece1996-0095","url":null,"abstract":"\u0000 The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines the effect of an opposing oscillatory flow on the local, instantaneous heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor.\u0000 Spectral and contact time analyses of local, instantaneous heat flux measurements from a heated, submerged horizontal cylinder clearly indicate that the bed hydrodynamics were significantly altered by the opposing secondary flow. These heat flux measurements were accomplished by employing an isothermal platinum film heat flux gage. For the present investigation, data were acquired for a monodisperse distribution of particles with a mean diameter of 345 μm and total fluidization ratios ranging from 1.1 through 2.7.\u0000 Heat transfer observed under conditions of secondary flows with a superimposed waveform exhibit characteristics of globally dominated, as opposed to locally dominated, hydrodynamics. For low primary and secondary flow rates and a forcing frequency of 5 Hz, a substantial enhancement in heat transfer was observed. Increases in the bubble phase and emulsion phase heat transfer coefficients were identified as the primary contributors to the observed increases in time-averaged local heat transfer coefficients.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128387760","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}

引用次数: 1

Waves and Instabilities in Inclined Gas-Liquid Pipe Flow 倾斜气液管道流动中的波与不稳定性

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0107

E. Grolman, J. Fortuin

{"title":"Waves and Instabilities in Inclined Gas-Liquid Pipe Flow","authors":"E. Grolman, J. Fortuin","doi":"10.1115/imece1996-0107","DOIUrl":"https://doi.org/10.1115/imece1996-0107","url":null,"abstract":"\u0000 The Modified Apparent Rough Surface (MARS) model (Grolman et al., 1996) successfully predicts liquid holdup and pressure gradient for wavy gas-liquid pipe flow in slightly inclined pipes, up to the transition to slug (intermittent) flow. Additional equations are used to predict the transition from wavy-to-intermittent flow and for the velocity of waves on the gas-liquid interface.\u0000 In this paper, Linear (stability) Theory is compared with the MARS model, on the basis of measurements in horizontal and slightly inclined (0° ⩽ β ⩽ 6°) pipes. Viscous terms in the linear analysis require estimates of shear stresses. Using the MARS model for the interfacial and liquid-to-wall friction factors, stability can be predicted to within reasonable degree of accuracy. Credible wave velocities are also obtained, provided the interfacial waves are not assumed to be marginally stable.\u0000 Earlier semi-theoretical equations (MARS model) still provide better estimates of both stability and wave velocity and are much easier to handle than Linear Theory. However, the use of good friction factor equations, i.e. those capable of predicting liquid holdup and pressure gradient, has significantly improved the results obtained with Linear Theory. This opens the way to further studies into the mechanisms determining the velocity, growth and instability of waves in gas-liquid pipe flow.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"65 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134640604","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}

引用次数: 1

Experimental Study of Phase Separation in Dividing Two Phase Flow 分两相流相分离实验研究

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0109

Q. Yong, Y. Zhilin, X. Jijun

引用次数: 2

Heat Transfer Characteristics for Some Coolant Additives Used for Water Cooled Engines 一些水冷发动机用冷却剂添加剂的传热特性

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0137

H. Abou-Ziyan, A. Helali

{"title":"Heat Transfer Characteristics for Some Coolant Additives Used for Water Cooled Engines","authors":"H. Abou-Ziyan, A. Helali","doi":"10.1115/imece1996-0137","DOIUrl":"https://doi.org/10.1115/imece1996-0137","url":null,"abstract":"\u0000 Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions; it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment.\u0000 This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or no enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for desolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121133816","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}

引用次数: 1

Capacitance Probes for Measurement of Liquid Film Thickness 测量液膜厚度的电容探头

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0112

X. Chen, T. Butler, J. P. Brill

引用次数: 2

Overall and Average Local Heat Transfer From a Horizontal Cylinder in a Gas-Fluidized Bed With an Opposing Oscillatory Flow 具有反向振荡流的气流化床卧式圆筒的整体和平均局部换热

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0123

D. Pence, D. E. Beasley

{"title":"Overall and Average Local Heat Transfer From a Horizontal Cylinder in a Gas-Fluidized Bed With an Opposing Oscillatory Flow","authors":"D. Pence, D. E. Beasley","doi":"10.1115/imece1996-0123","DOIUrl":"https://doi.org/10.1115/imece1996-0123","url":null,"abstract":"\u0000 The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines fundamental aspects of heat transfer in this hybrid combustor by measuring the effect of an opposing oscillatory flow on the overall and time-averaged local heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor.\u0000 Data were acquired for a monodisperse distribution of particles with a mean diameter of 345 μm and total fluidization ratios ranging from 1.1 through 2.7. Overall and time-averaged local heat flux measurements from the surface of a submerged horizontal cylinder show that heat transfer characteristics are significantly altered by an opposing oscillatory flow. Increases in overall heat transfer on the order of 12% were identified for operating conditions with low primary’ and secondary flow rates and low pulse frequencies. These enhancements were identified to be a consequence of significant localized enhancements. The fundamental trends and magnitude of the particle Nusselt number are effectively characterized by a modified form of the Strouhal number.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128135014","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}

引用次数: 0

Measurement of Local Mass Flux in a Circulating Fluidized Bed Using a Phase Doppler Particle Analyzer: A New Post-Processing Data Algorithm 用相位多普勒颗粒分析仪测量循环流化床的局部质量通量:一种新的后处理数据算法

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0117

T. V. D. Moortel, R. Santini, L. Tadrist

{"title":"Measurement of Local Mass Flux in a Circulating Fluidized Bed Using a Phase Doppler Particle Analyzer: A New Post-Processing Data Algorithm","authors":"T. V. D. Moortel, R. Santini, L. Tadrist","doi":"10.1115/imece1996-0117","DOIUrl":"https://doi.org/10.1115/imece1996-0117","url":null,"abstract":"\u0000 This study focused on the measurement of solid mass flux in the riser of a CFB cold pilot. The investigations were carried out using a Phase Doppler Particle Analyzer (PDPA). Inconsistencies in PDPA results were observed when investigating flows with high particle densities. It appears that the performance of the measuring technique was affected by the optical thickness of the measured medium, thus producing substantial overestimation of the global solid phase quantity (e.g., solid mass flux). To determine the origin of these inconsistencies, the measuring system was subjected to complete recalibration. It was found that in flows with high particle densities, noisy doppler signals tend to be split into several parts by the burst detector system, thus producing inconsistencies in the number of particles counted. The parameters associated with the splitting events were analyzed, and a post-processing algorithm was developed to limit PDPA measuring errors. The aim of the post-processing algorithm was to rebuild the data and to recover the original measurements. The reconstitution process was applied to solid mass flux measurements in a CFB cold pilot.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124334635","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}

引用次数: 2

Mixed Convective Heat Transfer for Fluid Flowing Through Annular Porous Medium 流体在环形多孔介质中的混合对流换热

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0110

B. Wang, J. Du, X. Peng

引用次数: 0

Analysis of Freezing in an Eccentric Annulus 偏心环内冻结分析

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/1.2888025

Yuwen Zhang, A. Faghri

引用次数: 16

A Study of Intermittent Flow in Downward Inclined Pipes 下斜管中间歇流动的研究

Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0101

Jiede Yang, C. Sarica, Xuanzheng T. Chen, J. P. Brill

{"title":"A Study of Intermittent Flow in Downward Inclined Pipes","authors":"Jiede Yang, C. Sarica, Xuanzheng T. Chen, J. P. Brill","doi":"10.1115/imece1996-0101","DOIUrl":"https://doi.org/10.1115/imece1996-0101","url":null,"abstract":"\u0000 The downward simultaneous flow of gas and liquid is often encountered in hilly terrain pipelines and steam injection wells. Most of the available methods for predicting the behavior of gas-liquid flow in pipes have been developed for horizontal and upward inclined pipes. In this study, co-current steady state slug flow in downward inclined pipes is investigated, experimentally and theoretically. A series of slug flow experiments are conducted with an air-kerosene system in a 2-in. diameter, 75-ft long pipe installed on an inclinable structure. Liquid holdup and pressure drop measurements are obtained for downward inclination angles from 0° to −90° at different flow conditions. Correlations for slug flow characteristics are obtained based on the experimental data. A mechanistic model based on a unit cell approach has been proposed for the prediction of the detailed slug structure, and subsequently the pressure gradient.\u0000 Fully developed slug flow could not be observed from −50° to −90°. A correlation was obtained for slug liquid holdup, and an analytical model and a correlation were developed for slug translational velocity. The lognormal distribution was found to best fit all the experimental slug length data. Equations for mean and design slug length were derived from the lognormal distribution function for inclination angles ranging from 0° to −30°. A slug frequency correlation was also developed.\u0000 The model can be used to predict intermittent flow behavior in downward inclined pipes. The correlations for slug liquid holdup, slug translational velocity, and slug length and frequency are closure relationships applicable to any model. Slug frequency information is also imperative for erosion and corrosion rate predictions.","PeriodicalId":324954,"journal":{"name":"Heat Transfer: Volume 3 — Experimental Studies in Multiphase Flow; Multiphase Flow in Porous Media; Experimental Multiphase Flows and Numerical Simulation of Two-Phase Flows; Fundamental Aspects of Experimental Methods","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122360197","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}

引用次数: 8