Eur. Phys. J. Plus (2018) 133: 454
https://doi.org/10.1140/epjp/i2018-12259-7

Regular Article

Entropy generation analysis as design criteria in dam-break flows for non-Newtonian fluids

Department of Mechanical Engineering, Hakim Sabzevari University, Sabzevar, Iran

^* e-mail: e.lakzian@hsu.ac.ir

Received: 28 August 2018
Accepted: 16 September 2018
Published online: 6 November 2018

Abstract

In the present study, a novel equation is presented for entropy generation (EG) in dam-break flows of Herschel-Bulkley fluids. The Herschel-Bulkley model is an idealized model of viscoplastic behavior. The dam-break phenomena can cause floods and widespread destruction in the path of the flow. Therefore, finding a measure for destruction analysis in downstream of the dam is important. Therefore, the EG is introduced as a criterion of destruction analysis in non-Newtonian dam-break flows. The Open-FOAM software is employed and simulations are done by the modified VOF method. Results are compared with experimental data, and a good agreement is achieved. The EG analysis of the Herschel-Bulkley fluid is presented for the first time. It is computed for different initial height (H₀), and the results show that the enhancement of H₀ causes the increment of EG. And, also, for an increment of EG, different shapes of bump are simulated and the geometry and bump distance from the dam are optimized. As a result, the triangle bump with , , and has the best performance in increasing the EG. Focusing on the destruction of the available work in the dam-break flows of Herschel-Bulkley fluids is important and useful for designing dams and structures in the downstream of dams.