A numerical study of rib augmented cooling of turbine blades is reported in this paper. The time-dependent velocity field around a pair of symmetrically placed ribs on the walls of a three-dimensional rectangular channel was studied by use of a modified version of Marker-And-Cell algorithm to solve the unsteady incompressible Navier-Stokes and energy equations. The flow structures are presented with the help of instantaneous velocity vector and vorticity fields, FFT and time averaged and rms values of components of velocity. The spanwise averaged Nusselt number is found to increase at the locations of reattachment. The numerical results are compared with available numerical and experimental results. The presence of ribs leads to complex flow fields with regions of flow separation before and after the ribs. Each interruption in the flow field due to the surface mounted rib enables the velocity distribution to be more homogeneous and a new boundary layer starts developing downstream of the rib. The heat transfer is primarily enhanced due to the decrease in the thermal resistance owing to the thinner boundary layers on the interrupted surfaces. Another reason for heat transfer enhancement can be attributed to the mixing induced by large-scale structures present downstream of the separation point.
本文报道了涡轮叶片肋增强冷却的数值研究。采用改进的mark - and - cell算法求解非定常不可压缩的Navier-Stokes方程和能量方程，研究了三维矩形通道壁上对称放置的一对肋周围随时间变化的速度场。利用瞬时速度矢量和涡度场、FFT以及速度分量的时均值和均方根值来描述流场结构。在再附着的位置上，展向平均努塞尔数增加。数值结果与已有的数值和实验结果进行了比较。肋的存在导致了复杂的流场，肋前后存在流动分离区域。由于表面安装的肋，流场的每一次中断都使速度分布更加均匀，并且在肋的下游开始形成新的边界层。传热主要是由于中断表面上较薄的边界层减少了热阻而增强的。传热增强的另一个原因可归因于分离点下游存在的大型结构引起的混合。
{"title":"Flow Characteristics in a Three-Dimensional Rectangular Channel With a Pair of Ribs Placed Symmetrically at the Channel Walls","authors":"M. Singh, P. Panigrahi, G. Biswas","doi":"10.1115/imece2000-1463","DOIUrl":"https://doi.org/10.1115/imece2000-1463","url":null,"abstract":"\u0000 A numerical study of rib augmented cooling of turbine blades is reported in this paper. The time-dependent velocity field around a pair of symmetrically placed ribs on the walls of a three-dimensional rectangular channel was studied by use of a modified version of Marker-And-Cell algorithm to solve the unsteady incompressible Navier-Stokes and energy equations. The flow structures are presented with the help of instantaneous velocity vector and vorticity fields, FFT and time averaged and rms values of components of velocity. The spanwise averaged Nusselt number is found to increase at the locations of reattachment. The numerical results are compared with available numerical and experimental results. The presence of ribs leads to complex flow fields with regions of flow separation before and after the ribs. Each interruption in the flow field due to the surface mounted rib enables the velocity distribution to be more homogeneous and a new boundary layer starts developing downstream of the rib. The heat transfer is primarily enhanced due to the decrease in the thermal resistance owing to the thinner boundary layers on the interrupted surfaces. Another reason for heat transfer enhancement can be attributed to the mixing induced by large-scale structures present downstream of the separation point.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127566675","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}
Radially rotating heat pipes have been proposed for cooling gas turbine disks working at high temperatures. A disk incorporating the heat pipe would have an enhanced thermal dissipation capacity and a much lower temperature at the disk rim and dovetail surface. In this paper, extensive numerical simulations have been made for heat-pipe-cooled disks. Thermal performances are compared for the disks with and without incorporating the heat pipe at different heating and cooling conditions. The numerical results presented in this paper indicate that radially rotating heat pipes can significantly reduce the maximum and average temperatures at the disk rim and dovetail surface under a high heat flux working condition. In general, the maximum and average temperatures at the disk rim and dovetail surface could be reduced by above 250 and 150 degrees, respectively, compared to those of the disk without the heat pipe. As a result, a disk incorporating radially rotating heat pipes could alleviate temperature-related problems and allow a gas turbine to work at a much higher temperature.
{"title":"A Numerical Analysis of Gas Turbine Disks Incorporating Rotating Heat Pipes","authors":"Y. Cao, J. Ling, R. Rivir, C. Macarthur","doi":"10.1115/imece2000-1461","DOIUrl":"https://doi.org/10.1115/imece2000-1461","url":null,"abstract":"\u0000 Radially rotating heat pipes have been proposed for cooling gas turbine disks working at high temperatures. A disk incorporating the heat pipe would have an enhanced thermal dissipation capacity and a much lower temperature at the disk rim and dovetail surface. In this paper, extensive numerical simulations have been made for heat-pipe-cooled disks. Thermal performances are compared for the disks with and without incorporating the heat pipe at different heating and cooling conditions. The numerical results presented in this paper indicate that radially rotating heat pipes can significantly reduce the maximum and average temperatures at the disk rim and dovetail surface under a high heat flux working condition. In general, the maximum and average temperatures at the disk rim and dovetail surface could be reduced by above 250 and 150 degrees, respectively, compared to those of the disk without the heat pipe. As a result, a disk incorporating radially rotating heat pipes could alleviate temperature-related problems and allow a gas turbine to work at a much higher temperature.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117190830","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}
The interphase is the region between the fiber and matrix whose properties strongly influence the overall composite behavior in terms of mechanical strength, chemical and thermal durability. The composition and thickness of the interphase region is governed by the processing conditions, in addition to the fiber surface treatments and other characteristics of the fiber and the resin materials. One of the strong contributing mechanisms to interphase formation is the preferential adsorption of matrix components onto the fiber surface, which takes place on the order of molecular scales. Chemical reaction in the matrix also happens simultaneously with the adsorption process. In this paper, a multi-layer adsorption-desorption-reaction model for a binary fluid mixture in contact with a solid surface is implemented to study the kinetics of interphase formation near bare fiber surfaces in thermosetting composite systems. Composition and thickness evolution of the interphase are predicted as functions of time. Conditions that lead to interphase formation upon vitrification are identified. Parametric studies are presented to investigate the effects of various nondimensional groups on the interphase region development.
{"title":"Modeling of Interphase Formation on Unsized Fibers in Thermosetting Composites","authors":"F. Yang, R. Pitchumani","doi":"10.1115/imece2000-1491","DOIUrl":"https://doi.org/10.1115/imece2000-1491","url":null,"abstract":"\u0000 The interphase is the region between the fiber and matrix whose properties strongly influence the overall composite behavior in terms of mechanical strength, chemical and thermal durability. The composition and thickness of the interphase region is governed by the processing conditions, in addition to the fiber surface treatments and other characteristics of the fiber and the resin materials. One of the strong contributing mechanisms to interphase formation is the preferential adsorption of matrix components onto the fiber surface, which takes place on the order of molecular scales. Chemical reaction in the matrix also happens simultaneously with the adsorption process. In this paper, a multi-layer adsorption-desorption-reaction model for a binary fluid mixture in contact with a solid surface is implemented to study the kinetics of interphase formation near bare fiber surfaces in thermosetting composite systems. Composition and thickness evolution of the interphase are predicted as functions of time. Conditions that lead to interphase formation upon vitrification are identified. Parametric studies are presented to investigate the effects of various nondimensional groups on the interphase region development.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128625108","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}
Variabilities in the preform structure in situ in the mold are an acknowledged challenge to effective permeation control in the Resin Transfer Molding (RTM) process. An intelligent model-based controller is developed which utilizes real-time virtual sensing of the permeability to derive optimal decisions on controlling the injection pressures at the mold inlet ports so as to track a desired flowfront progression during resin permeation. This model-based optimal controller employs a neural network-based predictor that models the flowfront progression, and a simulated annealing-based optimizer that optimizes the injection pressures used during actual control. Preform permeability is virtually sensed in real-time, based on the flowfront velocities and local pressure gradient estimations along the flowfront. Results are presented which illustrate the ability of the controller in accurately steering the flowfront for various fill scenarios and preform geometries.
{"title":"Neural Network Based Control of Preform Permeation in Resin Transfer Molding Processes With Real-Time Permeability Estimation","authors":"D. Nielsen, R. Pitchumani","doi":"10.1115/imece2000-1473","DOIUrl":"https://doi.org/10.1115/imece2000-1473","url":null,"abstract":"\u0000 Variabilities in the preform structure in situ in the mold are an acknowledged challenge to effective permeation control in the Resin Transfer Molding (RTM) process. An intelligent model-based controller is developed which utilizes real-time virtual sensing of the permeability to derive optimal decisions on controlling the injection pressures at the mold inlet ports so as to track a desired flowfront progression during resin permeation. This model-based optimal controller employs a neural network-based predictor that models the flowfront progression, and a simulated annealing-based optimizer that optimizes the injection pressures used during actual control. Preform permeability is virtually sensed in real-time, based on the flowfront velocities and local pressure gradient estimations along the flowfront. Results are presented which illustrate the ability of the controller in accurately steering the flowfront for various fill scenarios and preform geometries.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126322026","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}
It has been shown that artificial neural networks (ANNs) can be used to simulate and control thermal systems such as heat exchangers. It is known that the characteristics of thermal components such as heat exchangers vary with respect to time mainly due to fouling effects. There is a need of a model that can adapt to the new characteristics of the thermal system. In this work adaptive artificial neural networks are used to control the outlet air temperature of a heat exchanger test facility. The neurocontrollers are adapted on-line on the basis of different criteria. The parameters of the ANNs are modified considering target error and stability conditions of the closed loop system analyzed as a nonlinear iterative map. We also implement a minimization of a performance index that quantifies the energy consumption. It is shown numerically and experimentally that the neural network is able to control the thermal facility, and is also able to adapt to different disturbances applied to the system, while minimizing the amount of energy used.
{"title":"Adaptive Neurocontrol and Minimization of Energy Consumption of a Heat Exchanger Test Facility","authors":"Gerardo Díaz, M. Sen, R. McClain","doi":"10.1115/imece2000-1468","DOIUrl":"https://doi.org/10.1115/imece2000-1468","url":null,"abstract":"\u0000 It has been shown that artificial neural networks (ANNs) can be used to simulate and control thermal systems such as heat exchangers. It is known that the characteristics of thermal components such as heat exchangers vary with respect to time mainly due to fouling effects. There is a need of a model that can adapt to the new characteristics of the thermal system. In this work adaptive artificial neural networks are used to control the outlet air temperature of a heat exchanger test facility. The neurocontrollers are adapted on-line on the basis of different criteria. The parameters of the ANNs are modified considering target error and stability conditions of the closed loop system analyzed as a nonlinear iterative map. We also implement a minimization of a performance index that quantifies the energy consumption. It is shown numerically and experimentally that the neural network is able to control the thermal facility, and is also able to adapt to different disturbances applied to the system, while minimizing the amount of energy used.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130805458","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}
An experimental study was performed to investigate the influence of freestream vortical structures on stagnation region heat transfer. A heat transfer model with a cylindrical leading edge was tested in a low speed wind tunnel at Reynolds numbers ranging from 67,750 to 142,250 based on leading edge diameter of the model. Turbulence generating grids of parallel rods of diameter, 2.86 cm, 1.59 cm and 0.95 cm, were placed upstream of the heat transfer model in horizontal and vertical orientations to generate freestream turbulence with different orientations of vortical structures. The rods in horizontal orientation were perpendicular to the stagnation line and those in vertical orientation were parallel to the stagnation line of the heat transfer model. The distance between the grid and heat transfer model was varied from 25 to 125 rod diameters. The grids with rods in the horizontal orientation, where the primary vortical structures are expected to be perpendicular to the stagnation line, result in higher heat transfer than with the grids where the rods are in the vertical orientation. The difference in heat transfer with the two grid orientations decreases with increasing grid-to-model distance for a given rod-grid. The difference also decreases with decreasing rod size for a given normalized grid-to-model distance. For the 2.86 cm rod-grid, the difference in heat transfer augmentation between horizontal and vertical grid-orientations is highest at the stagnation line and decreases with streamwise distance. This difference, however, remains fairly constant over the whole stagnation region for the 1.59 cm and 0.95 cm rod-grids.
{"title":"Influence of Freestream Vortical Structures on Stagnation Region Heat Transfer","authors":"A. Oo, C. Ching","doi":"10.1115/imece2000-1457","DOIUrl":"https://doi.org/10.1115/imece2000-1457","url":null,"abstract":"\u0000 An experimental study was performed to investigate the influence of freestream vortical structures on stagnation region heat transfer. A heat transfer model with a cylindrical leading edge was tested in a low speed wind tunnel at Reynolds numbers ranging from 67,750 to 142,250 based on leading edge diameter of the model. Turbulence generating grids of parallel rods of diameter, 2.86 cm, 1.59 cm and 0.95 cm, were placed upstream of the heat transfer model in horizontal and vertical orientations to generate freestream turbulence with different orientations of vortical structures. The rods in horizontal orientation were perpendicular to the stagnation line and those in vertical orientation were parallel to the stagnation line of the heat transfer model. The distance between the grid and heat transfer model was varied from 25 to 125 rod diameters. The grids with rods in the horizontal orientation, where the primary vortical structures are expected to be perpendicular to the stagnation line, result in higher heat transfer than with the grids where the rods are in the vertical orientation. The difference in heat transfer with the two grid orientations decreases with increasing grid-to-model distance for a given rod-grid. The difference also decreases with decreasing rod size for a given normalized grid-to-model distance. For the 2.86 cm rod-grid, the difference in heat transfer augmentation between horizontal and vertical grid-orientations is highest at the stagnation line and decreases with streamwise distance. This difference, however, remains fairly constant over the whole stagnation region for the 1.59 cm and 0.95 cm rod-grids.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126139094","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}
We photographed water droplets (550 μm diameter) as they impacted on a stainless steel surface. We varied droplet impact velocity (10–40 m/s) and the average surface roughness (0.03–0.23 μm) of the steel plates used as test surfaces in our experiments. A piezoelectric droplet generator was used to produce water droplets. The stainless steel substrate was mounted on the end of a rotating arm, giving linear velocities of up to 40 m/s. A CCD video camera was used to photograph droplets impinging on the substrate. By synchronizing the ejection of a single droplet with the position of the rotating arm and triggering of the camera, different stages of droplet impact were photographed. From these photographs we measured the size of droplets as they spread. It was observed that as the impact velocity increased, finger-shape perturbations around the spreading droplet became longer and narrower. At sufficiently high velocities the tips of these fingers detached, producing satellite droplets. Increasing surface roughness was found to promote splashing and reduce the velocity at which splashing was first observed. By increasing surface roughness, both the number of fingers and the maximum extent of spreading were decreased. At high impact velocities the spreading liquid film became so thin that it ruptured in several places.
{"title":"Splashing of a Small Droplet Impinging on a Solid Surface at High Velocity","authors":"N. Z. Mehdizadeh, S. Chandra, J. Mostaghimi","doi":"10.1115/imece2000-1498","DOIUrl":"https://doi.org/10.1115/imece2000-1498","url":null,"abstract":"\u0000 We photographed water droplets (550 μm diameter) as they impacted on a stainless steel surface. We varied droplet impact velocity (10–40 m/s) and the average surface roughness (0.03–0.23 μm) of the steel plates used as test surfaces in our experiments. A piezoelectric droplet generator was used to produce water droplets. The stainless steel substrate was mounted on the end of a rotating arm, giving linear velocities of up to 40 m/s. A CCD video camera was used to photograph droplets impinging on the substrate. By synchronizing the ejection of a single droplet with the position of the rotating arm and triggering of the camera, different stages of droplet impact were photographed. From these photographs we measured the size of droplets as they spread. It was observed that as the impact velocity increased, finger-shape perturbations around the spreading droplet became longer and narrower. At sufficiently high velocities the tips of these fingers detached, producing satellite droplets. Increasing surface roughness was found to promote splashing and reduce the velocity at which splashing was first observed. By increasing surface roughness, both the number of fingers and the maximum extent of spreading were decreased. At high impact velocities the spreading liquid film became so thin that it ruptured in several places.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121865378","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}
New applications have been identified for thermal spraying using micro-droplets. Mechanisms of impact, fragmentation, and solidification developed for millimeter size droplets are no longer applicable for micro-droplets due to the significance of the surface tension and wall interaction. New fragmentation mechanisms and advanced numerical modeling are required to develop a better understanding of the transport phenomena for droplet spreading and solidification. In this paper, the existing fragmentation mechanisms have been reviewed, and a new mechanism is proposed. The proposed mechanism considers the effects of flow instability, wettability, surface roughness, surface chemistry, and moisture absorption. This mechanism has been incorporated into an advanced numerical model that consists of a multizone adaptive grid generation used for tracking the movement of the solidification interface and a curvilinear level-set method for capturing the movement of free surface. Impact, fragmentation, and solidification of a molybdenum micro-droplet has been simulated, and the fragmentation morphology has been predicted.
{"title":"Mechanism and Modeling of Micro-Droplet Impact, Fragmentation, and Solidification","authors":"H. Zhang","doi":"10.1115/imece2000-1495","DOIUrl":"https://doi.org/10.1115/imece2000-1495","url":null,"abstract":"\u0000 New applications have been identified for thermal spraying using micro-droplets. Mechanisms of impact, fragmentation, and solidification developed for millimeter size droplets are no longer applicable for micro-droplets due to the significance of the surface tension and wall interaction. New fragmentation mechanisms and advanced numerical modeling are required to develop a better understanding of the transport phenomena for droplet spreading and solidification. In this paper, the existing fragmentation mechanisms have been reviewed, and a new mechanism is proposed. The proposed mechanism considers the effects of flow instability, wettability, surface roughness, surface chemistry, and moisture absorption. This mechanism has been incorporated into an advanced numerical model that consists of a multizone adaptive grid generation used for tracking the movement of the solidification interface and a curvilinear level-set method for capturing the movement of free surface. Impact, fragmentation, and solidification of a molybdenum micro-droplet has been simulated, and the fragmentation morphology has been predicted.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128099287","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}
A continuum solidification model is used to study transport phenomena in a simulated Czochralski system for various rotation rates of the crystal and crucible. Solidification occurs on a cylindrical seed from the top surrounded by water in the crucible. An enthalpy formulation is adopted for numerical solution of convection-diffusion controlled solidification problems. Predicted solid-liquid interface and temperature distribution are in good agreement with the liquid crystal visualization experiments.
{"title":"Thermal Analysis of Solidification in a Czochralski-Type Rotating System","authors":"J. Xu, M. Ferland, H. Zhang, V. Prasad","doi":"10.1115/imece2000-1484","DOIUrl":"https://doi.org/10.1115/imece2000-1484","url":null,"abstract":"\u0000 A continuum solidification model is used to study transport phenomena in a simulated Czochralski system for various rotation rates of the crystal and crucible. Solidification occurs on a cylindrical seed from the top surrounded by water in the crucible. An enthalpy formulation is adopted for numerical solution of convection-diffusion controlled solidification problems. Predicted solid-liquid interface and temperature distribution are in good agreement with the liquid crystal visualization experiments.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133170443","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}
This study refers to the technical feasibility of a continuous process for manufacturing pre-pregs and copper-clad laminates for electronic applications, with the aim to overcome three critical technological challenges, the elimination of environmentally detrimental solvents, elimination of voids and elimination of cure/temperature history variability between laminates. The new approach is based on the concept of injection pultrusion or continuous RTM. The centerpiece of the process is the impregnation die. Glass fabric and resin are fed into the die where impregnation and depending of the design, partial reaction occurs. The B-staging, if not finished in the die, will be done in an oven located immediately after. The final cure and lamination occurs in a continuous belt clamp. In the present paper, we discuss the chemo-rheology of a potential resin system and use it to establish the technical feasibility of the process.
{"title":"Technical Feasibility of a New Solventless Approach to Manufacture Pre-Pregs and Laminates for Electronic Applications","authors":"L. Dehnke, Ranjeet R. Hogade, J. Castro","doi":"10.1115/imece2000-1489","DOIUrl":"https://doi.org/10.1115/imece2000-1489","url":null,"abstract":"\u0000 This study refers to the technical feasibility of a continuous process for manufacturing pre-pregs and copper-clad laminates for electronic applications, with the aim to overcome three critical technological challenges, the elimination of environmentally detrimental solvents, elimination of voids and elimination of cure/temperature history variability between laminates. The new approach is based on the concept of injection pultrusion or continuous RTM. The centerpiece of the process is the impregnation die. Glass fabric and resin are fed into the die where impregnation and depending of the design, partial reaction occurs. The B-staging, if not finished in the die, will be done in an oven located immediately after. The final cure and lamination occurs in a continuous belt clamp. In the present paper, we discuss the chemo-rheology of a potential resin system and use it to establish the technical feasibility of the process.","PeriodicalId":306962,"journal":{"name":"Heat Transfer: Volume 3","volume":"350 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133182731","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}
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