共查询到17条相似文献,搜索用时 62 毫秒
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运用计算流体动力学(CFD)方法,对中心龙卷流型搅拌槽内部流场进行数值模拟,并且和标准搅拌槽进行了分析比较。结果表明:和标准搅拌槽相比,中心龙卷流型搅拌槽的功率准数较小,节能效果显著。流体流经导流板,可以获得较大的轴向速度,在槽中心可以形成理想的中心龙卷流,从而有利于固体颗粒的悬浮。 相似文献
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将破碎核函数应用于群体平衡模型(PBM)中,并与计算流体力学(CFD)方法进行耦合,开展了不同类型搅拌桨组合下搅拌槽内液滴尺寸分布和液-液分散特性的模拟研究。结果表明:推进桨(TXL)可促进流体的轴向混合,涡轮桨(RT)有利于流体分散,不同搅拌桨组合下的流场特征存在显著的差异;相同转速下抽吸桨(PM)+TXL组合桨拥有较小的功率消耗,而RT+RT组合桨的功率消耗较大;挡板的存在能够有效促进液滴破碎,且挡板对PM+RT组合桨搅拌下分散性能的影响显著大于另外两种搅拌桨组合。基于本研究结果,在双层桨搅拌槽的工业应用中,应首先考虑挡板的应用,在对液滴分散性能要求较小时,应优选带轴流型的PM+TXL组合桨;在对液滴分散性能有较高的要求时,应优选带档板的PM+RT组合桨。 相似文献
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稀土混合澄清槽中搅拌对油水分离的影响 总被引:1,自引:0,他引:1
Oil-water separation is critical to solvent extraction process of rare earth, which can directly affect the yield andquality of the product. The experiments measure the two-phase separation time in a beaker, mixing uniformity of two phasesin the mixer and the oil phase entrainment at oil exit by the Karl Fischer method and numerical simulation for the mixersettlerto study the combined effect of gravity and stirring. Experimental results show that relative to the static situation, theseparation efficiency resulted from low-speed stirring is increased by 25%. The water content in the oil is a minimum at anoffset distance L of 10 cm and the clearance off the tank bottom z of 10 cm is as low as 0.49%. Distribution images of oilwaterseparation at 2 s indicates that stirring is very conducive to the separation of the oil-water phase. 相似文献
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对搅拌槽内的重要参数———气泡直径进行了数值模拟。结果表明,在搅拌槽内排出流区和循环区内模拟值与实验值吻合较好。在模拟过程中仅考虑了湍流动能耗散率对气泡大小的影响,没有考虑到气泡自身的凝并和循环过程,所以在循环区中模拟值比实验值稍大。 相似文献
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研究了应用于液-液气两相流引射器的特性,建立了引射器气液两相湍流流动的数学模型,进行了以液体为工作流体,同时抽吸气、液两相介质的二维全流段数值仿真。重点研究了不同混合室长度对引射器性能的影响,结果表明,当混合室长度lH=6d3(混合室直径)时,气液两相流体混合较为均匀且沿程损失较小,还可满足经济性要求,因此lH=6d3为最佳混合室长度尺寸,此时引射器中的流体具有明显的射流特征。 相似文献
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This study experimentally and numerically investigated the effect of pressure of the casting vessel on the solidification characteristics of a DNAN (2,4-dinitroanisole)/RDX(cyclotrimethylenetrinitramine) melt-cast explosive. The solidification and cooling time was recorded by a thermocouple, the distribution of the shrinkage porosity was observed and analyzed, and the density of the explosive charge was measured. The primary solidification characteristics were verified by numerical simulation achieved with ProCAST casting software, and results were in qualitative agreement with experimental results. Both the experimental and numerical results demonstrate that increasing pressure of the casting vessel can effectively diminish the shrinkage porosity, reduce the solidification time, and increase the relative density of the DNAN/RDX melt-cast explosive. 相似文献
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�¸�������в���������Ҵ������� 总被引:2,自引:0,他引:2
本文以岩石学、油层物性、毛细管压力曲线等为依据,并结合气井测试资料,划分出溶蚀孔洞型、孔隙型、角砾白云岩型和微细孔隙型等4种储层类型。指出岩相、成岩和构造作用是控制陕甘宁盆地中部气田白云岩储层最主要的地质因素。 相似文献
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高温气流中液滴蒸发特性的研究 总被引:3,自引:0,他引:3
采用液滴蒸发实验装置,以悬挂液滴法研究液滴蒸发特性,考察了液滴蒸发的规律及气流速度和气流温度对液滴蒸发的影响。实验结果表明,液滴蒸发经历初始加热的非稳态阶段和后期的稳态阶段,非稳态过程液滴蒸发速率起伏很大,稳态过程蒸发稳定,液滴直径的平方随蒸发时间呈直线变化;在整个蒸发过程中,在475~500 K内存在一个气流温度临界值,小于临界值,气流温度越高,液滴初始加热时间与液滴生存时间的比值(Φi)越大,大于临界值,气流温度越高,Φi越小;提高气流温度和气流速度都能加速液滴的蒸发。 相似文献
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运用FLUENT有限元仿真软件,采用标准k-ε湍流模型,分别对规格DN350 mm×DN250 mm、DN350 mm×DN150 mm的同心异径管和偏心异径管进行流体流动的特性分析。结果表明,当流体从入口管流经变径处时,流速突然变化,产生扰动涡旋,使得静压值发生波动,继而出现最值;流速在变径出口处达到最大值,这使得异径管与平管段的接管处受到严重冲蚀,降低管道的使用寿命。建议在施工时在变径处应采用耐腐蚀性强的钢材或增加管道的壁厚,同时加强变径连接处的焊缝检测。 相似文献
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�¸�������в�����ϵ�绯�Ǵ������� 总被引:3,自引:0,他引:3
??The carbonatite reservoir of Ordovician weathered crust in Shanganning Basin belongs to palaeokarst and its main reservoir spaces are denudation vugs. In the light of palaeokarst genesis and growth characteristics, the parameters and distribution characteristics of Carbonatite reservoir are comprehensively analysed by using the data of capillary pressure curve, cast wafer, cathode light and physical properties, Analysing reservoir availability and discussing pore-cave-fracture combination relations, four reservoir types are divided to provide geological basis data for gas exploration and reserve calculation. 相似文献