Local Energy Losses for Wave-Type Flows at Abrupt Bottom Changes

EROĞLU N., TAŞTAN K.

JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING, cilt.146, sa.9, 2020 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 146 Sayı: 9
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1061/(asce)ir.1943-4774.0001498
  • Dergi Adı: JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Agricultural & Environmental Science Database, Applied Science & Technology Source, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Communication Abstracts, Compendex, Computer & Applied Sciences, Environment Index, Geobase, INSPEC, Metadex, Pollution Abstracts, Veterinary Science Database, DIALNET, Civil Engineering Abstracts
  • Anahtar Kelimeler: Abrupt bottom drop, Abrupt bottom rise, Drag coefficient, Local energy loss, Wave-type flow, HYDRAULIC JUMPS, NUMERICAL-SIMULATION, STEP
  • Gazi Üniversitesi Adresli: Evet

Özet

Low-head hydraulic structures, like weirs or barrages, are constructed on rivers for irrigation or power-generation purposes. As the upstream water level rises due to these structures, it is necessary to build an energy-dissipation structure such as a stilling basin downstream of the low-head hydraulic structures. The control of hydraulic jumps using abrupt bottom elevation changes at stilling basins may cause wave-type flows. In this study, wave-type flows at abrupt bottom rises and drops were investigated experimentally. For practical reasons, it is important to predict the local energy losses encountered at bottom changes for wave-type flows. Empirical equations for local energy losses and loss coefficients were obtained by evaluating the experimental results for various values of rise or drop heights, discharges, and tailwater depths. The local energy loss in wave-type flows was compared to that of a simple hydraulic jump. It is shown that for some cases local energy losses may become larger than the local energy loss in a simple hydraulic jump. Furthermore, it is difficult to predict the force on a step in the case of wave formation. In this study, a drag coefficient was obtained experimentally to compute the force acting on the step. The variation of this drag coefficient with relative step height is presented.