EFFECT OF GEOMETRY COMPUTATIONS AND NUMERICAL SCHEME ON THE RESISTANCE COEFFICIENT FOR UNSTEADY FLOW IN IRREGULAR CHANNELS | ||||
| ERJ. Engineering Research Journal | ||||
| Article 5, Volume 25, Issue 4, October 2002, Page 73-89 PDF (994.82 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/erjm.2001.70952 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Moustafa A. El-Enany | ||||
| Assistant Prof., Dept. of Civil Eng., Faculty of Engineering, Menufiya University, Shebin El-Kom, Egypt. | ||||
| Abstract | ||||
| The problem of predicting flow resistance coefficient with sufficient accuracy. is of great interest to hydraulic engineers. Realistic estimate of hydraulic resistance is important to the proper design and analysis of irrigation and drainage networks. Resistance (roughness) coefficient is a compound function of the geometric properties of the channel, the fluid properties, and the varied flow conditions prevalent in the open channel system. The purpose of this study is to demonstrate the response of the applied method of irregular geometric properties computation, the used numerical scheme, and the distance interval adopted in the numerical model on the calibrated value of resistance coefficient. The rectangular grid scheme of the method of characteristics is applied with different methods of irregular geometric properties computation and different value of distance interval. While, the Leap-Frog finite difference scheme is used with only one method of geometric properties computation and one value of distance interval. Measured field data of Tanta Navigation canal are used to feed and calibrate the numerical models. Results of numerical experiments illustrate that inaccurate channel geometry representation in the numerical models leads to incorrect value for the calibrated value of roughness coefficient. Findings also demonstrate that the applied numerical scheme as well as the schematization to describe the channel geomeby by a series of discrete representation along the reach being modeled has significant effect on the calibrated value of the roughness coefficient. | ||||
|
Statistics Article View: 77 PDF Download: 140 |
||||
