A Combined O/U-Tube Oscillatory Water Tunnel for Fluid Flow and Sediment Transport Studies: The Hydrodynamics and Genetic Algorithm

Water

Jia-You Chen¹  Cheng-Hsien Lee¹  Li-Chiu Chang²  Fang-Shou Lee³ 

[1] Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan;Department of Water Resources and Environmental Engineering, Tamkang University, New Taipei City 251, Taiwan;Long Win Science and Technology Corporation, Yangmei, Taoyuan 326, Taiwan;

关键词: oscillatory water tunnel;    O/U-tube;    hydrodynamics;    sediment transport;    genetic algorithm;   

DOI  :  10.3390/w14111767

来源: DOAJ

【 摘 要 】

This study proposes an oscillatory water tunnel (O/U-tube) equipped with two impellers to drive flows. The O/U-tube consists of two modes: U-tube mode and O-tube mode. The former can generate oscillatory flow, while the latter can produce both oscillatory and unidirectional flows with velocities up to 1.6 m/s. The hydrodynamics of the U-tube and O-tube modes were examined analytically. For the U-tube mode, a sine-varying rotational speed for the impeller caused higher harmonic components for the velocity, owing to the local inertia and gravity forces. In the steady state of the O-tube mode, owing to the resistance force, the flow velocity was proportional to the rotational speed. To generate the target flow conditions, two open-loop control schemes were proposed according to the analytic approach for the U-tube mode and a genetic algorithm for the O-tube mode. The analytic approach was based on a hydrodynamic model with a given flow condition. In the genetic algorithm, the rotational speed was represented by a square root of the Fourier series. The optimal coefficients of the Fourier series to generate the target flow were determined by using the genetic algorithm and the hydrodynamic model. Both approaches were experimentally validated. Consequently, the O/U-tube with the open-loop schemes can be used to generate the desired oscillatory and unidirectional flows.

【 授权许可】

Unknown