分布参数液体管道的分段近似状态空间模型

PIECEWISE APPROXIMATION STATE SPACE MODELS OF DISTRIBUTED PARAMETER LIQUID PIPES

关键词:  分布参数  推进剂输送  动力学仿真  模态分析

Key words:  Distributed parameter  Propellant transfer  Dynamic simulation  Modal analysis

摘要:

分别提出了分布参数层流和湍流液体管道的分段近似状态空间模型，模型考虑了稳态摩擦和频率相关摩擦损失两种情况，层流管道的分段近似状态空间模型是线性的，而湍流管道的是非线性的。包括频率相关摩擦损失的模型比只考虑稳态摩擦损失的模型更精确地描述流体管道的瞬变过程，但模型的阶次成倍地增加了。用单根管道阀门关断的水击问题仿真计算对模型进行了验证，采用２个分段的分段近似状态空间模型的计算结果已经与特征线方法的计算结果吻合较好。

Abstract:

The piecewise approximation state space models of laminar flow and turbulent distributed parameter liquid pipes,which take both steady state friction and frequency dependent friction into consideration,are presented respectively.The laminar flow pipes’piecewise approximation state space model is linear and the turbulent pipes’ one is nonlinear.The models including the frequency dependent friction can more precisely predict the dynamic performance of the fluid lines transients than the ones only considering the steady state friction,whereas its order increase by times.Corroboration of our models was given by simulated results of the water hammer with single pipe after valve closure and the calculated results using our models with two segments already show good agreement with those using method of characteristics