共查询到16条相似文献,搜索用时 203 毫秒
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通过水模型实验和数值模拟,研究了不同湍流控制器下两流非对称中间包内流体流动特性。数值模拟结果表明:湍流控制器几何结构对两流非对称中间包流体流动特性有明显影响。圆形湍流控制器内流场涡心靠近底部,出口处流体流速垂直向上;中间包流场涡心靠近长水口,涡心高度与挡墙高度基本同高,中间包表面波动大,容易发生卷渣现象。不对称长方形湍流控制器底部为不对称波浪形,流场涡心靠近出口,流体以一定角度从湍流控制器出口流出;其右侧出口面积大于左侧,水口右侧流体流量大于左侧;由于增大了出口面积,出口处流体速度减小,中间包表面平稳。水模型结果表明采用不对称湍流控制器中间包两流之间的平均停留时间差比圆形湍流控制器中间包减少1/4,算术平均值增加5.3%,说明非对称湍流控制器增强了中间包去除夹杂物能力且能有效缩小两流之间流体流动的差异。 相似文献
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薄板坯连铸中间包内抑湍器的模拟研究 总被引:3,自引:0,他引:3
控制中间包内钢液的合理流动对夹杂物的排除有重要影响,为此建立了模拟薄板坯连铸中间包流动情况的水模型。通过测定停留时间分布(RTD)曲线,研究了不同组合控流装置对中间包流体流动特性的影响。结果表明,结构及尺寸合理的抑湍器能延长水口响应时间及平均停留时间、提高活塞流区体积分数及降低死区体积分数;抑湍器与单坝组合的控流装置在控制流体流动方面效果极佳,而抑湍器与单墙单坝、单墙双坝组合的控流装置的控流效果不太理想。 相似文献
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Hans‐Jürgen Odenthal Ralf Blling Herbert Pfeifer Jrg‐Friedrich Holzhauser Franz‐Josef Wahlers 《国际钢铁研究》2001,72(11-12):466-476
The fluid flow in a continuous casting tundish affects the separation of non‐metallic particles and the cleanliness of the steel. Today, laser‐optical investigations of water models are state of the art and enable detailed information about the effect of baffles, i. e. dams, weirs and turbo‐stoppers, on the flow. In this work 3D‐LDA and 2D‐DPIV‐investigations for different turbo‐stoppers in a water model on a scale of 1:1.7 of a 16 t single strand tundish are presented. Three circular turbo‐stoppers are investigated. Detailed measurements of the mean velocity and turbulence intensity in the tundish with and without turbo‐stopper are shown. With a suitable turbo‐stopper geometry the recirculation area in the tundish centre and short‐circuit flows along the side walls can be avoided and thus more favourable residence time distributions can be obtained. It is shown that the turbo‐stopper produces higher turbulence in the inlet region of the tundish, which is spatially more limited, however, in relation to the flow without turbo‐stopper. Thereby a more homogeneous flow is created at the discharge of the tundish with better conditions for the particle separation. The experimental data yield a good understanding of the flow phenomena in a tundish with turbo‐stopper and are used as validating criterion for numerical simulations (Fluent 5.5) on the basis of the Reynolds equations. The turbulence modelling is based on a two‐equation model (realizable k‐ε model). 相似文献
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通过采用水模拟和数值模拟分别对中间包不同结构进行全因素试验,研究了双挡坝结构对钢液流动行为的影响,着重探讨了不同类型的双挡坝中间包内钢液的流动状态和速度分布。结果表明:低坝应设置在高坝后,顶端钢液流速将减小29%,降低浇注末期发生卷渣的概率;低坝应与高坝流钢孔同高,钢液的平均停留时间可达到最大稳定值;高低坝距离差为40~160mm时,流体流动状态较稳定,低坝后无漩涡产生。分析认为:中间包入口区和出口附近均为强湍流状态,其他区域均为过渡流状态,入口区利于夹杂物的碰撞长大,应至少保证该区域长度大于中间包长度的1/4,出口区强湍流易产生大夹杂物导致水口堵塞,应控制在出水口附近0.25m的区域内。 相似文献
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《钢铁研究学报(英文版)》2014
Fields of fluid flow and temperature, and residence time distribution (RTD) curves were investigated by mathematical simulation in a one-strand tundish for continuous casting. It was known from the investigation that a big “spring uprush” formed on surface around the long shroud when molten steel flowed into a turbulence inhibitor (TI) with extending lips and rushed up reversely out of the TI, while four small “spring uprushes” existed on surface when a TI without extending lips because the liquid steel flowed mainly out of the 4 corners of the TI. The flow of liquid steel in the former tundish configuration was not reasonable and the height of an area where temperature was less than 1819 K was about half of liquid surface height on the right side of the stopper, which meant that big dead zone existed in the former tundish configuration. In the optimal one, the height of such area was only seventh of the liquid surface height. The RTD curves obtained from the mathematical simulation basically agreed with those from the physical modeling and the flow characteristics obtained from these two methods agreed with each other. 相似文献
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Physical and mathematical determination of the influence of input temperature changes on the molten steel flow characteristics in slab tundishes 总被引:1,自引:0,他引:1
S. López-Ramírez J. De Barreto P. Vite-Martínez J. A. Romero Serrano C. Duran-Valencia 《Metallurgical and Materials Transactions B》2004,35(5):957-966
Transient fluid flow behavior in a tundish with two different arrangements, a bare tundish and a tundish using flow control
devices, was studied using physical modeling and a mathematical model. The study places special emphasis on buoyancy effects,
particularly transient buoyancy effects due to step change in inlet temperature. For the bare tundish case, the inertial forces
are strongly dominant, while in the arrangement using flow control devices, tundish with turbulence inhibitor and low dams,
the buoyancy forces are dominant. The results were compared to those representing the real behavior, considering temperature
variations, for each tundish arrangement. This comparison made possible the determination of the probable implicit error that
could be present in the estimation of the fluid flow characteristic behavior used for the design of the tundish geometry and
flow control devices when the temperature variations are not considered. 相似文献