Abstract
To accurately calculate the transient response in laminar flow, it is necessary to use frequency-dependent friction considering the velocity distribution. We developed a high speed and accurate computing method for simulating the friction in transient laminar pipe flow in the method of characteristics. This method consists of approximating W. Zielke's weighing function as a sum of impulse responses of first order lag systems. This method is normally well-understood. However, it is not usually applied to other calculating methods except the method of characteristics. Because the method of characteristics has a limit to its unique relation between discrete time and space, it is difficult to apply it to complicated pipe systems that include branches. In this paper, we propose application of the high speed and accurate calculating method of frequency-dependent friction to the CIP method. This proposed method has a higher flexibility than the method of characteristics in terms of the relation between discrete time and space. We measured transient response in the single, series, branch and complex pipelines. The results of the numerical calculation agree well with that of the experiment. These results show the effectiveness of the proposed method.
