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在对大型锻件传热分析的基础上,建立了大型锻件的物理模型,对其温度场的变化规律进行了模拟计算,同时将模拟结果和实验结果进行了对比分析,并通过实例说明了热处理过程数值模拟方法的准确性和优越性,为进一步分析此类工件的组织转变和应力应变等奠定了基础. 相似文献
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《Canadian Metallurgical Quarterly》2013,52(3-4):213-228
AbstractThis study describes the numerical modeling of three-dimensional coupled turbulent flow, heat transfer, and solidification in a continuous slab caster for stainless steel. The model uses generalized transport equations which are applicable to the liquid, mushy and solid regions within the caster. The turbulent characteristics in the melt pool and mushy region are accounted for using the low-Reynolds number k–ε turbulence model by Launder and Sharma. This version of the low-Reynolds number turbulence model is found to be more easily adaptable to the coupled flow and mushy region solidification caster problem compared to the standard high-Reynolds number and other low-Reynolds number turbulence models. The macroscopic solidification process itself is based on the enthalpy-porosity scheme. The governing transport equations are solved employing the primitive variables and using the control volume based finite-difference scheme on a staggered grid. The process variables considered are the casting speed and the inlet superheat of the melt. The effects of these process variables on the velocity and temperature distributions and on the extent of the solidification and mushy regions are reported and discussed. The numerical predictions of solidification profile are compared with the limited experimental data available in the literature, and very good agreement was found. © 1998 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved. Résumé Cette étude decrit la modélisation numerique de l'écoulement turbulent couple, à trois dimensions, du transfert de chaleur et de la solidification, lors du coulage en continu de dallé d'acier inoxydable. Le modéle utilisé des equations generalisées de transport qui sont applicables aux regions liquides, pateuses et solides à l'interieur de l'equipement de coulage. On tient compte des caractéristiques turbulentes du bain fondu et de la région pateuse en utilisant le modéle de turbulence a petit nombre de Reynolds k–ε, de Launder et Sharma. Cette version du modèle de turbulence à petit nombre de Reynolds est plus facilement adaptable à l'écoulement couple et la solidification de la région pateuse du problème de coulage que la version utilisant un nombre de Reynolds normal, élevé, ou que d'autrés modèles de turbulence à petit nombre de Reynolds. Le procédé meme de solidification macroscopiqué est base sur la combinaison enthalpié-porosite. On resout les équations de transport qui gouvernent en employant les variables primitives et enutilisant la mèthode des différences finies basée sur le volume de contrôle, sur une grille alterne. Les variables considerées dans ce procédé sont la vitesse de coulage et la surchauffe du liquide a l'entrée. On rapporte et discute de l'effet de ces variables du procédé sur la distribution de velocité et de température et sur l'étendue des régions solides et pateuses. On compare les prédictions numériqués du profil de solidification avec les données expérimentales limitées disponibles dans la litterature et on trouvé une très bonne concordance. © 1998 Canadian Institute of Mining and Metallurgy. Published by Elsevier Science Ltd. All rights reserved. 相似文献
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采用自制回转窑换热装置对离心粒化后的高温炉渣颗粒进行余热回收,采用有限元分析软件及欧拉双流体模型对装置内气固两相流场进行数值模拟,研究进风风速及回转窑转速对气固换热效率的影响,并通过现场试验对模拟结果进行验证。结果表明,当回转体转速为16r/min、进风风速4.31 m/s时,颗粒的离散效果较好,热风温度达1 050K,此时的换热效果最好,数值模拟与试验结果高度吻合。 相似文献
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从物理模型和数学模型两方面对冶金炉的磁场模拟方法进行了论述,对各种磁场模拟方法进行了比较、分析,阐明了冶金炉的磁场模拟不仅要考虑电流产生的磁场,还必须考虑铁磁屏蔽的影响。 相似文献
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紧卷罩式退火的温度场模拟 总被引:6,自引:0,他引:6
紧卷罩式退火炉在钢板生产中广泛使用,该炉包括以N2和H2混合气体为保护气体的传统罩式炉和以100%H2作为保护气体的全氢罩式炉。模拟罩式退火温度场对确定和优化钢板的退火制度、预报钢板的机械性能极为重要。本文介绍了影响罩式退火炉效率的因素,并着重论述了钢卷罩式退火的温度场模拟的原理及实现手段。 相似文献
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在分析氧化铝回转窑传热过程的基础上,运用多相流理论对回转窑内横截面物料流动与传热过程进行数值模拟,研究了不同工况下横截面上的温度分布及流动情况。结果表明,截面上物料温度主要受气体及窑壁传热影响,物料颗粒越小,其内部温度上升越快,流动带起的物料高度也越低,但截面上物料内部温度分布基本趋于一致,并可忽略截面温差。 相似文献
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本文将三维附面层方程抛物型化,对不同尺寸的等温小加热块自然对流换热进行了数值模拟,并用来研究微电子集成电路芯片的冷却问题. 相似文献
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应用欧拉双流体模型对内埋单支换热管的浅层气-固(空气-石英砂颗粒)流化床进行了数值模拟,在换热管周围建立了4个观测点,得出了沿换热管圆周方向流动状况和局部瞬时换热系数的变化.结果显示:在换热管中心水平面的左右两侧壁面处颗粒更新速度较快,并有气泡上升,局部换热系数的变化也较强烈;在管壁下部颗粒运动相对平稳,并有颗粒在此滞留,局部换热系数变化相对较缓;在管壁上部颗粒有堆积,这使得颗粒体积分数在此处变化较小,局部换热系数变化也较为平缓. 相似文献
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Fumitaka Tsukihashi 《钢铁研究学报(英文版)》2011,(Z2):243-250
The unsteady turbulent flow during the continuous casting of steel is important, because it influences critical phenomena that affect steel quality. Unsteady three-dimensional flow in the mold region of the liquid pool during continuous casting of steel slabs has been computed using realistic geometries starting from the submerged inlet nozzle to the mold. The cassette filter function was used to deal with unsteady Navier-Stokes equation, and then the turbulent flow in the thin slab CCM was simulated with the large eddy simulation method combined with the Smagorinsky sub-grid scale model in this paper. And the model was verified by the Particle Image Velocimetry (PIV) experimental results which was got from a relate scientific literature. In this thesis, by means of LES, the flow characteristics in the thin slab CCM were acquired, such as the vortex distribution, the formation of the large eddy coherent structures, development, shedding and fracture process. In the same time, the turbulent asymmetric distribution was revealed even the nozzle in the centre position. Interactions between the two halves cause large velocity fluctuations near the meniscus. And the vortex is located at the low velocity side adjacent to the SEN. Along with the unsteady time development, the unsteady turbulent large vortex structures of the liquid steel in the CCM presented periodic bias flow distribution, and the period is about 20 seconds. 相似文献
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利用电磁场基本理论,对熔锌工频有心感应炉熔沟建立相关的物理和数学模型,求解了熔沟内电磁场和温度场分布。为熔沟参数优化设计提供了参考依据。 相似文献