引用本文: | 刘昆,张育林.分布参数管道的一种改进的小分段数有限元模型.[J].国防科技大学学报,1998,20(4):5-8.[点击复制] |
Liu Kun,Zhang Yulin.A Modified Small Element-number Finite Element Model for Distributed Parameter Fluid Pipes[J].Journal of National University of Defense Technology,1998,20(4):5-8[点击复制] |
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分布参数管道的一种改进的小分段数有限元模型 |
刘昆, 张育林 |
(国防科技大学 航天技术系 湖南 长沙 410073)
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摘要: |
在分段数为1和2时, 现有有限元模型的一阶谐振频率比一维分布参数模型的一阶谐振频率低许多, 因而其适用的频率范围较低, 计算精度较差。本文提出了一种改进的小分段数有限元模型, 通过修正流体管道的并联导纳使分段数为1和2时的有限元模型的一阶谐振频率与一维分布参数模型一致, 从而提高了其使用的频率范围和计算精度。利用单根管道阀门关闭的水击问题的仿真计算对改进模型的效果进行了验证。在分段数为2时, 原有的有限元模型的计算结果与分布参数模型的计算结果相差较大, 而改进后的模型的计算结果与分布参数模型的计算结果基本一致。 |
关键词: 分布参数, 流体管道, 分段近似, 集中参数, 模型 |
DOI: |
投稿日期:1997-12-10 |
基金项目: |
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A Modified Small Element-number Finite Element Model for Distributed Parameter Fluid Pipes |
Liu Kun, Zhang Yulin |
(Department of Aerospace Technology, NUDT, Changsha, 410073)
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Abstract: |
The existing finite element model is suitable only for low frequency range and not precise because to its first order resonant frequency is much lower than that of one-dimension model when its element number is 1 and 2. A modified small element-number finite element model is pressented here, it equates its first order resonant frequency to that of one-dimension model by modifying the shunt admittance of the pipes when the element number n=1 and n=2, therefore increases its usage frequency range and computation precision greatly. Corroboration of our model's modified effectiveness is given by the simulated results of the water hammer of a single pipe after valve closure. When n=2, the calculated results obtained by using the existing finite element model deviate from those obtained by using one-dimension model obviously , but the calculated results by using the modified finite element model agree well with these by using one-dimension model. |
Keywords: distributed parameter, fluid pipes, piecewise approximation, lumped parameter, models |
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