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The hydrodynamic problem of a two-dimensional model of seafloormining tool entering still water vertically at constant speed was analyzed based on the velocity potential theory.For the assumption that the water entry occurs with very short time interval,the viscosity and gravity of fluid were neglected.Considering the characteristic shape of it,the seafloormining tool was simplified as a flat-bottom body.The governing equations were the Reynolds time-averaged equations and the k-ε model.Finite element analy... 相似文献
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A numerical wave load model based on two-phase (water-air) Reynolds-Averaged Navier Stokes (RANS) type equations is used to evaluate hydrodynamic forces exerted on flatted-bottom seafloor mining tool during its entering ocean waves of deploying process. The discretization of the RANS equations is achieved by a finite volume approach (FV). The volume of fluid method (VOF) is employed to track the complicated free surface. A numerical wave tank is built to generate the ocean waves which are suitable for deploying seafloor mining tool. A typical deploying condition is employed to reflect the process of flatted-bottom body impacting with waves, and the pressure distribution of bottom is also presented. Four different lowering velocities are applied to obtain the time histories of maximum pressure of bottom, and it can be concluded that the pressure coefficient decreases with water velocity increasing, which is similar with ordinary water entry case. The numerical results clearly demonstrate the characteristics of flatted-bottom body entering ocean waves. 相似文献
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综合运用齿轮啮合学、摩擦学和传热学知识,精确计算了轮齿不同啮合位置的摩擦热流密度以及轮齿啮合面、端面的对流换热系数。利用ANSYS软件建立了直齿轮单个轮齿的有限元模型,获得了轮齿的本体温度场,分析了扭矩、转速以及润滑油输入温度等关键参数对轮齿本体温度场的影响。研究结果表明:轮齿最高温度区域分布在轮齿啮合接触面的中心部位,轮齿啮合面温度沿齿宽方向近似呈抛物线分布;轮齿的最高温度随扭矩、转速和润滑油输入温度的增加而增加;仿真值和试验值基本吻合,证明仿真分析方法可用于齿轮本体温度场的研究。 相似文献
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齿轮喷油润滑系统润滑效率与喷嘴布置角度、喷油速度等参数有关,但目前的喷嘴布置角度多数采用经验设计,缺乏精确性且时间成本高。针对高线速度齿轮的喷油润滑问题,基于CFD(计算流体力学)方法建立高线速度直齿轮的喷油润滑流体计算模型,对喷油润滑中齿轮旋转产生的气流干涉问题进行分析;通过流场流线图确定最优喷嘴角度:绕入啮合区气流与齿面首个接触点向小齿轮的偏转角度,并研究齿轮传动比和转速等参数对喷嘴角度布置的影响。结果表明:齿轮旋转产生的气流干涉会形成进入啮合区的气流,沿该气流方向布置喷嘴角度相比传统布置方式润滑效率提升了24.4%,齿轮周围气流流动状况和最优喷嘴角度只与齿轮几何结构有关,与工况参数设置无关。 相似文献
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在电弧炉向超高功率发展的趋势中,已有的电弧炉不可能弃之不用而追求全新的发展。3t、5t电弧炉在我国现有的电弧炉中还占有相当大的比重,因此,在现有的设备和产品的基础上,发挥潜力,改进结构,提高性能,达到稳产、高产和节能的目的,仍是一个值得重视的问题,近年来,我厂对这两种电炉作了如下的改进。 相似文献
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为选用合理的固液两相流动模型用于深海扬矿泵内矿物浆体的计算。针对深海海底矿物具有颗粒粒级跨度大且粒径大的特点,本文分别选用粗颗粒-均质浆体计算模型和固液两相混合物浆体计算模型,开展扬矿泵数值模拟分析。研究发现,粗颗粒-均质浆体计算模型计算得到的内部流场与固液两相混合物浆体计算模型得到的内部流场是相似的,所以该模型可以用来分析扬矿泵的内部流场;该模型减少了颗粒追踪数量可以节约计算时间;将两种计算方法得到的扬矿泵外特性与试验结果进行比较,发现该模型计算得到的泵扬程与功率均更接近试验结果,说明该模型在扬矿泵性能计算是有优势的。 相似文献
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