Critical flow in open channels: Numerical solution using the Newton-Raphson method for Android 4.0 applica-tion.

Abstract

Context: In this article we present an algorithm under JavaScript source code for critical flow equation solution. Method: An object-oriented programming language was implemented for Android 4.0 or higher systems based on iterative and incremental processes (Agile development). The numerical method of Newton-Raphson was used to determine the critical depth of seven hydraulic sections (rectangular, trapezoidal, asymmetric trapezoidal, triangular, asymmetric triangular, parabolic and circular). A potential function was obtained to establish the seed value in iterative process, in order to accelerate and guarantee the convergence level for each section. This value is directly associated with hydraulic problem pre-established conditions. Results: The application calculates: critical depth, critical speed, hydraulic area, specific energy, wet perimeter and mirror. The results calculated by the application were validated against Excel analysis tool (Goal Seek) results and Hcanales® software developed by Máximo Villón Béjar Engineer. Finally, the application is available for free in Google Play Store, with the name "Critical Flow in Channels. Newton Raphson Solution". Conclusions: It is possible to develop easily accessible applications that meet the technical conditions required for the resolution of engineering-related situations.