共查询到20条相似文献,搜索用时 125 毫秒
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中间包双板多孔挡墙流行控制去除夹杂物效果的模拟研究 总被引:4,自引:0,他引:4
为净化钢液、提高夹杂物在中间包内的上浮率,提出一种新型中间包挡墙流动控制形式-双板多孔挡墙流动控制。通过数值模拟方法结合水模型实验,对中间包内流体流动及夹杂物的传输行为进行了分析研究。结果表明,采用多孔挡墙流动控制可以有效地改变中间包内流场分布,促进夹杂物上浮,提高钢水清洁度。 相似文献
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方坯连铸非稳态充型过程流场温度场耦合数值模拟 总被引:3,自引:1,他引:2
采用CFD商用软件Flow-3d,对C的质量分数为0.2%的碳钢165mm×165mm方坯连铸非稳态充型过程中结晶器内钢水在流场、温度场耦合作用下的凝固和流动状况进行数值模拟。结果表明,内置冷却器在连铸充型过程中可以明显地提高传热效率,降低钢液冲击深度。内冷却器对钢液的流动影响很大,可以减缓钢液的流动速度,减少冲击深度,并能使钢液的流动更加均匀,提高铸坯质量。 相似文献
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利用有限元软件ANSYS/LS-DYNA对薄壁零件黏性介质外压缩径过程中模具与筒坯之间摩擦因数对变形的影响进行有限元分析模拟。结果表明:在缩径过程中筒坯料的变形速度方向与作用在表面的黏性介质的运动方向始终保持一致。模具与筒坯的摩擦因数的临界值是0.12,当小于0.12时,摩擦因数对缩径成形过程的影响较小;当大于0.12时,随着摩擦因数的增大,其对缩径成形过程的影响不断加剧。改善模具与筒坯之间的界面润滑条件有助于缩径成形极限的提高。 相似文献
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A new type of jet‐in‐slit testing apparatus for a specimen, chilled with a peltier element, was developed to investigate corrosion on the heat transfer surface of an aluminum alloy heat exchanger, in contact with a liquefaction gas at cryogenic temperature and in flowing seawater. The specimen can be chilled, even under flowing conditions, using this apparatus. Corrosion tests and polarization measurements of a specimen chilled by a peltier element were carried out in flowing seawater at various temperatures. The effect of chilling a specimen was equivalent to the effect achieved for a test in solution at a lower temperature. The process was dependent on a passive film, formed on the surface of the aluminum alloy specimen, as evidenced by polarization measurements. The extent of corrosion damage increased with increasing temperature of the solution, and showed maximum damage at high temperature. At high temperatures, erosion‐corrosion was found at the central part of the specimen, but the effect of flow was negligible at low temperature. Corrosion tests for a cathodically polarized specimen were conducted under flowing conditions. Corrosion damage was accelerated by cathodic polarization at lower temperatures. 相似文献
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为了解决高拉速生产条件下CSP板坯表面质量问题,利用数值计算软件FLUENT针对某厂CSP连铸机水口插入深度对结晶器流场及液面波动的影响进行了数值模拟研究。研究结果表明,不同的水口浸入深度结晶器内流场基本相同,增加水口浸入深度对结晶器流场影响不明显,水口浸入深度的大小直接决定了从水口流出的流股撞击结晶器窄面位置的高低,同时得出,当水口浸入深度从300、340增大到380 mm时,液面处最大流速分别为0.180、0.160和0.127 m/s;增大水口浸入深度,结晶器上回流对结晶器液面的扰动将减弱,对应的卷渣次数减少。 相似文献
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Underwater laser ablation has become an alternative machining process that is able to reduce the thermal damage in work materials caused by lasers. However, the disturbance of water to the laser beam is a crucial concern for the ablation performance in water and cut surface quality obtained. In this study, a new laser ablation technique has been proposed, in which a waterjet was applied to impinge the top workpiece surface in order to form a thin and flowing water layer. With the assist of such water layer during the laser ablation, the redeposition and heat-affected zone can be minimized. Titanium alloy (Ti–6Al–4V) selected as a work sample was grooved by using a nanosecond-pulse laser under different machining conditions. The cut geometry and heat-affected zone were observed and analyzed to justify the process performance. The metallurgical change and cracks that occurred on and underneath the groove surface were also investigated in this study. The experimental results revealed that a clean cut with less thermal damage can be obtained when the workpiece was ablated by a laser under the flowing water layer. In addition, a narrower and deeper groove can be fabricated when a higher waterjet flow rate was applied. The laser ablation under the flowing water layer developed in this study could be a potential method for machining titanium alloy or even other thermal-sensitive materials. 相似文献
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设计并建立了实验室模拟流动海水腐蚀试验装置。对A3、20#、X70钢挂片和20#钢管路在流动人工海水中全浸暴露2、4、8、16、32天的腐蚀行为进行了试验研究。试验结果表明,流动海水中碳钢的腐蚀速率先降后升,然后趋于稳定;在动水试验中,锈层分为两层,底层以Fe3O4为主,表层以Fe2O3为主;在静水试验中,锈层以Fe2O3为主。 相似文献
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提出一种新的仪表阀体的多向可控精密成形工艺,利用有限元模拟软件Deform-3D,对仪表阀体的多向可控精密成形工艺进行了数值模拟。分析了零件的工艺难点及成形过程中的载荷-行程曲线、金属流动规律及不同摩擦系数对成形过程的影响,最后进行了试验验证。研究结果表明,提出的仪表阀体多向可控精密成形新工艺是可行的,模拟得到的锻件充填饱满,在成形过程中金属流动比较均匀,金属流线基本沿锻件轮廓方向,最大载荷为6.21×106 N;此外,摩擦系数对成形过程的影响较大,工艺试验得到的产品和模拟结果具有较好的一致性,锻件尺寸一致性也较好,说明工艺可靠,对该类零件的多向可控精密成形工艺具有一定的指导意义。 相似文献
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针对6A02合金的特性及型材的质量要求,在挤压机出料台上用水封和风冷两种冷却方式对6A02挤压型材淬火工艺进行了试验 。 相似文献
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汽车轮毂轴管复合挤压成形数值模拟与试验研究 总被引:3,自引:0,他引:3
根据热挤压成形理论,针对汽车轮毂轴管零件自身的特点,采用复合挤压成形工艺进行热成形,借助DE-FORM-3D有限元软件对成形过程进行了模拟、分析。以镦挤成形工序和反挤压成形工序为重点,分析了成形过程中金属的流动规律及应力、应变的分布情况,得到载荷-行程曲线。同时在试验时研究了加热温度、挤压速度、润滑等主要工艺参数对金属流动、应力应变、成形质量和成形力的影响。并以此为依据,对工艺参数进行了优化,验证了数值模拟结果的正确性及该复合挤压成形工艺的可行性。 相似文献