钢液真空循环精炼过程的数学模拟

1　Introduction　Withuninterruptedlyincreasinginthedemandforultracleansteel,thevacuumcirculation (RH)refiningprocesshasnowbecomeaprinciplerefiningoperationforreducingthecarbonanddegassingofmoltensteel.VariousrefiningtechnologiesusingoxygenorpowderinjectionandblowingintheRHtreatmentformakingultralow carbonandultralow sulphursteelhavebeendevelopedinrecentyears[1 10 ] .Actually ,theRHre finingprocesshasbeenextendedtobecomeamulti functionrefiningtechnology ,whichisenabledtore movecarbon ,oxygen …     

物理问题的数学模型与物理教学的素质教育

本通过在物理教学中引导学生根据物理问题建立数学模型的教学经验，探讨了如何在物理教学中提高学生运用物理理论解决实际问题的能力，进而把物理教学与素质教育有效地结合起来。     

RH和RH-KTB精炼过程中钢液流动和混合特性的研究

The flow and mixing characteristics of molten steel during the vacuum circulation refining,including RH(Ruhrstahl-Heraeus) and RH-KTB(Ruhrastahl-Heraeus-Kawasaki top blowing) processes,were investigated on a 1/5 linear scale water model of a 90t multifunction RH degasser,The circulation rate was directly and more accurately determined,using a new method by which the more reliable results can be obtained.The fluid flow pattern and flow field in the ladle were demonstrated,observed and analyzed.The mixing time of liquid in the ladle was measured using electrical conductivity method.The residence time distribution in the RH model was obtained by tracer response technique.The influence of the main technological and geometric factors,including the gas top blowing*(KTB) operation,was examined.The results indicated that the circulation rate of molten steel in the RH degasser can be fairly precisely calculated by the formula:Q1p=0.0333Qg^0.26Du^0.69Dd^0.80(t/min),where Qg-the lifting gas flow rate(NL/min);Du and Dd-the inner diameters of the up and down-snorkels(cm),respectively.The maximum value of circulation rate of molten steel in the case of the 30cm diameters either of the up-and down-snorkels for the RH degasser(the “Saturated” rate) is approximately 31 t/min.the corresponding gas flow rate is 900NL/min.Blowing gas into the vacuum chamber through the top lance like KTB operation does not markedly influence the circulatory flow and mixing charateristics of the RH process under the conditions of the present work.There exist a major loop and a large number of small vortices and eddies in the ladle during the RH refining process.A liquidliquid two-phase flow is formed between the descnding stream from the down-snorkel and the liquid around the stream.All of these flow situation and pattern will strongly influence and determine the mixing and mass transfer in the ladle during the refining.The correlation between the mixing time and the stirring energy density is τmε^0.50 for the RH degasser.The mixing time rapidly shortens with an increase in the lifting gas flowrate.At a same gas flow rate,the mixing times with the up-and down-snorkel diameters either of 6 and 7cm are essentially same.The 30cm diameters either of the up-and down-snorkels for the RH degasser would be reasonalble.The concentration-time curve showed that three circulation cycles are at least needed for complete mixing of the liquid steel in the RH degasser.     

线材冷却过程模拟计算的数学模型

建立了线材斯太尔摩冷却过程有内热源的一维非稳态数学模型;以CCT曲线为依据计算线材冷却过程的相变潜热,利用能量平衡法对数学模型进行离散求解,得出线材在冷却过程中搭接点与非搭接点处的温降规律,并通过现场测试验证了模拟计算结果的准确性.     

传染病数学模型的马尔可夫骨架过程建模

利用侯振挺教授等人提出的马尔可夫骨架过程理论讨论了传染病数学模型。通过对此模型进行马尔可夫骨架过程建模,得出结论:在任一时刻上的传染病人数L(t)是某线性方程的最小非负解。     

阳极焙烧炉传热过程数学模型的建立与应用

用有限差分法建立有关阳极焙烧炉传热过程的离散方程,采用Ｋ—ε双方程湍流模 型和ＳＩＭＰＬＥ算法讨论气体绕流的扩展Ｋ－ε模型,从而分别得到焙烧炉内主要点的温度场和气 流分布等流场信息．     

物理过程的教学探讨

在物理学的学科课程教学中，实施素质教育、培养具有创新意识和创新才能的优秀人才是物理学学科课程教学改革的根本任务。如何在教学中培养学生的创新意识和创新才能，是当前高校教学改革和高校教师必须研究的重大问题．对于这些问题我门必须提高和统一认识。我们认为，高校的教学改革是通过教师的学科课程的教学改革进行的，只有通过教师的教学才能培养学生的创新意识和创新才能，     

阳极焙烧炉传热过程数学模型的建立与应用

用有限差分法建立有着阳极焙烧米听离散方程,采用Ｋ－ε双方程湍流模型和ＳＩＭＰＬＥ算法讨论气体绕流的扩展Ｋ－ε模型,从而分别得到焙烧炉内主要点的温度场和气流分布等流场信息。     

巧建数学模型消除物理方程中多余的物理量

在物理问题中，经常碰到这么一种现象，即根据问题条件可以列出m个方程，可方程中却有n（n〉m）个未知数．那么如何处理这种未知数多，方程少的问题呢？下面介绍几种消除多余未知数的数学模型．     

巧建数学模型消除物理方程中多余的物理量

在物理问题中,经常碰到这么一种现象,即根据问题条件可以列出m个方程,可方程中却有n（n〉m）个未知数,那么如何处理这种未知数多,方程少的问题呢？下面介绍几种消除多余未知数的数学模型。     

钢液真空循环精炼过程的物理模拟

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