共查询到18条相似文献,搜索用时 234 毫秒
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针对化工过程装备中经常遇到的圆柱壳双开孔-接管结构,采用有限元分析方法获得轴向和环向双开孔-接管结构的应力集中系数分布图。分析结果表明,开孔率和开孔间距大小是影响筒体开孔接管区应力分布的主要因素。开孔率决定了开孔影响区的范围以及结构的最大应力集中系数,而开孔间距的变化直接影响到筒体孔桥部位上最大应力水平。研究结果为此类结构安全评定及优化设计提供有效手段。 相似文献
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φ3400丙烯塔塔底封头强度的有限元分析 总被引:1,自引:4,他引:1
按《钢制压力容器——分析设计标准》(JB4732-95),采用ANSYS通用有限元分析软件,在考虑包括内压栽荷和薄膜应力的条件下,对丙烯塔塔底封头、筒体与裙座连接处,封头与接管连接处的局部不连续结构进行了应力分析,并根据所得数据结果进行强度检验,以确定塔底封头强度是否合格或需要进行补强处理。 相似文献
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旋风分离器壳体切向矩形接管有限元分析 总被引:1,自引:1,他引:0
文章采用有限元法对旋风分离器的切向矩形接管段进行了应力计算,并进行了强度评定。由于筒体开矩形孔并接切向接管导致接管与筒体连接区域应力分布复杂,矩形接管与筒体相切部位变形最大且沿径向被拉伸;该筒段应力最大处在筒体与切向接管连接处的内壁面;依据JB4732对危险截面进行了应力强度评定,结果表明该旋风分离器切向矩形管强度满足安全要求。图5表2参9 相似文献
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基于ANSYS软件对压力容器开孔接管区的应力与疲劳分析 总被引:2,自引:0,他引:2
文章利用ANSYS有限元软件对压力容器开孔接管区进行应力分析,获得了开孔接管区的应力强度分布图,得到最大应力发生在筒体最高位置与接管的连接处,最大应力强度值为247.478 MPa。然后利用ANSYS进行疲劳寿命分析,将有限元方法与疲劳寿命分析理论相结合,得到累积使用系数均小于1,即开孔接管部位满足疲劳强度的要求,因此该容器是安全的。通过此次分析再次证明了ANSYS软件为压力容器实际工程应用中提供了可靠的、高效的理论依据。图4表3参11 相似文献
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针对凸形封头与筒体不连续引起局部范围内应力迅速增大,使压力容器强度削弱的现象,利用有限元分析软件ANSYS,以球形封头、椭圆形封头和碟形封头这3种凸形封头为研究对象,考察不连续现象对其应力分布和应力集中系数的影响,并对其进行优化。结果表明:3种凸形封头压力容器的最大应力出现在不连续区域;远离不连续区域,应力基本维持不变,为薄膜应力; 3种凸形封头削边长度出现临界值;对3种凸形封头削边段进行优化,球形封头压力容器优化效果最理想。研究结果对于凸形封头与筒体不连续区域应力分布及优化有一定的参考意义。 相似文献
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为了提高制造辅助喷嘴的成品率,通过对现有喷气织机引纬系统中辅助喷嘴的性能及生产工艺分析,指出辅助喷嘴头部形状、电极参数设计、喷口加工工装是影响其成品率的主要因素。提出以下改进措施:①改进成型模具上模角度和下模弧度的设计参数,使辅助喷嘴的内腔更为合理;②合理设置电极参数,可改善喷口粗糙度Ra值高引起风速低的问题,也可提高打喷口速度,提高工作效率;③根据不同喷口形状,利用电加工设备无切削力的特点,设计出合理的加工工装,并对装配夹具和工装进行改进,使产品性能和生产效率有较大提高,改进后辅助喷嘴成品率由75%左右提高到90%以上。 相似文献
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根据水刺加工工艺要求设计了圆锥圆柱型、流线型、圆柱圆锥型3种喷水孔结构。采用大型流体计算软件(CFD)模拟水流流过喷水孔内部的流体流动通道,在大气中形成动力水针过程,并依据数值模拟结果分析喷水孔结构对水针断裂长度的影响。经分析认为圆锥圆柱型喷水孔结构使水针表面易于发散形成水雾,水针断裂长度短;流线型喷水孔结构降低了流体流动通道对水流流动的扰动程度,水针断裂长度有所提高;而圆柱圆锥型喷水孔结构最利于水针保持柱状结构状态,水针断裂长度最长。 相似文献
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本课题依托国家海洋公益性行业科技专项。由于采用水射流技术进行扇贝剥离加工有加工质量好;闭壳肌剥离完整;清洁卫生加工原料易获得等诸多优点,故利用水射流技术对海湾扇贝闭壳肌剥离进行研究分析,以期得出一种新型的扇模式。由于喷嘴为该剥离设备的关键部件,而喷嘴参数变化会对流场速度分布产生影响。因此本文利用扇贝剥离加工的窄角扇形喷嘴内部流场的二维数学模型,将窄角扇形喷嘴网格模型用quad—dominated(四边形占优)形式进行划分。并通过FLUENT流体计算软件,采用标准湍流模型对窄角扇形喷嘴内部流场进行了仿真,通过分析喷嘴锥角、出口直径、出口长度等变化对出口处流场速度分布影响,得出适用于水射流加工扇贝的喷嘴的最优参数组合。 相似文献
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In this paper, a three‐dimensional numerical simulation is presented on the flow field inside the nozzle of Murata vortex spinning. Four parameters; nozzle pressure; jet orifice angle, twisting surface angle, and distance between the nozzle inlet and the spindle, are selected to investigate their influences on the airflow characteristics in the nozzle and, consequently, on yarn tensile properties. Experimental research is also conducted to investigate the influence of these parameters on the yarn tensile property. The computational results are compared with the experimental results and they are in good agreement. The research shows that with the increase of the nozzle pressure and the twisting surface angle, the yarn tenacity first increases and then decreases. Yarn tenacity increases with increasing jet orifice angle. Yarn tenacity decreases with the increasing distance between the nozzle inlet and the spindle. 相似文献
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The technique of reducing yarn hairiness using an air-jet nozzle on the winder (JetWind) is a combination of the ring and air-jet spinning technologies. The dynamics of the hair inside the nozzle plays an important role in the JetWind process. In this study, a dynamical model for the coupling between a protruding surface hair on the ramie yarn and the airflow in the JetWind process is developed. Based on the model, numerical simulation of the dynamics of the hair in the nozzle is performed and the principle of reducing yarn hairiness is theoretically shown. The simulation result is validated by the experimentally captured motional configurations of the hair in the nozzle using high-speed photography technique. The effects of two nozzle parameters—the injector angle and yarn passage diameter on the dynamics of the hair and in turn, yarn hairiness are investigated by both numerical simulation and experiments. 相似文献
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虾壳不同部位制备甲壳素、壳聚糖的研究 总被引:2,自引:0,他引:2
本文采用红外光谱、扫描电镜作为为甲壳素、壳聚糖的性能参数的主要分析手段,分析了用EDTA脱钙法制备甲壳素、壳聚糖时,虾壳组织发生的变化以及由虾壳不同部位制得的甲壳素、壳聚糖在结构、性能参数等方面的异同。其结果为:本文所采用的EDTA脱钙法制备甲壳素、壳聚糖的工艺合理;由虾壳不同部位:虾头、虾身、虾足和虾头内容物三组试样所制得的甲壳素、壳聚糖其结构基本一致,但其脱乙酰度和相对分子量有较大差别,其中以虾头壳制备的甲壳素、壳聚糖的相对分子质量最大,而脱乙酰度则是虾足、虾头内容物所制得的试样较高。 相似文献
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为降低辅助喷嘴能耗,增强辅喷气流的集束性,提高生产效率和织物质量,分析了辅助喷嘴结构参数和供气压力对射流特性的影响。运用流体动力学软件Fluent对不同供气压力下单圆孔、正三角形孔和星形孔3种典型辅助喷嘴结构的三维流场模型进行数值模拟,得到在0.2~0.4 MPa供气压力下3种辅助喷嘴对称面的速度云图、中心轴线速度、耗气量及引纬速度平稳性,提出了评定辅助喷嘴综合性能的方法。并将单圆孔辅助喷嘴数值计算得到的中心线速度和径向速度与实验值进行了比较,验证了数值仿真结果的正确性。结果表明,当供气压力相同时,星形孔辅助喷嘴气流集束性、引纬平稳性最好,耗气量小,综合性能最优。 相似文献
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A special hairiness-reducing nozzle was attached on a winding machine. The design and attachment of the nozzle should not change the yarn twist and strength. The hairiness-reducing mechanism of the nozzle was analysed, which utilised an air-jet to produce the rotating air stream to perform false twisting, detwisting and wrapping of the yarn so as to wrap the hairiness onto or twist it into the main yarn body, thus reducing the yarn hairiness. The position and method for attaching the nozzle were introduced. The hairiness index, hairiness appearance, twist and strength of the yarn, which was produced by the winding machine attached with the nozzle were examined. The results indicated that the processed yarns have their hairiness index lowered, hairiness appearance improved, and the twist and strength remained unchanged, which verified the hairiness-reducing effect of the nozzle. Fabric pilling property and surface features were measured for fabrics in which the filling yarns were through the winding machine with the nozzle. The results showed that the fabrics had less pilling and a smoother surface. 相似文献