Evaluation the Hydraulic Aspects of Stepped Labyrinth Spillway

Abstract

This study was adopted a new concept to enhance performance of stepped spillway towards more dissipation of kinetic energy along chute face through increases interlocking surface areas between the mainstream and trapping cavity recirculation vortices on the tread of chute steps and each step edge that beneath it, and increasing the interaction of the flow interference over stepped spillway. The aim of this concept is by employment the specification of a labyrinth weir by configured as a stepped spillway, to produce new steps named as Labyrinth stepped spillway. Experiments were restricted in skimming flow regimes, it have been carried out on four physical models with chute angles (35°). Where models are classified into three labyrinth stepped spillway models of three different magnification length ratios L T /W=1.1, 1.2, and 1.3, additionally; a traditional or conventional shape models were used for comparison. All physical models assembled with step height 4 cm, eight steps constructed for a total height of 32 cm and width of 30 cm .The results generally show that the energy dissipation with labyrinth shape stepped spillway was more than resulted with the traditional shape. As the magnification ratio increase, the energy dissipation observed to increase compare with traditional model. ‫اﻟﮭﯿﺪ‬ ‫اﻟﺴﻤﺎت‬ ‫ﺗﻘﯿﻢ‬ ‫ر‬ ‫وﻟﯿﻜﯿﺔ‬ ‫اﻟﻤﺘﺪرج‬ ‫اﻟﻤﺘﻌﺮج‬ ‫ﻟﻠﻤﻄﻔﺢ‬ ‫اﻟﺨﻼﺻــــﺔ‬ ‫ﺗﺒﻨﺖ‬ ‫اﻟﺪراﺳﺔ‬ ‫ھﺬه‬ ‫ﻋﻠﻰ‬ ‫اﻟﺤﺮﻛﯿﺔ‬ ‫اﻟﻄﺎﻗﺔ‬ ‫ﺗﺸﺘﺖ‬ ‫ﻋﻠﻰ‬ ‫ﻗﺎﺑﻠﯿﺘﮫ‬ ‫ﻟﺰﯾﺎدة‬ ‫اﻟﻤﺪرج‬ ‫اﻟﻤﻨﺤﺪر‬ ‫أداء‬ ‫ﻟﺘﺤﺴﯿﻦ‬ ‫ﺟﺪﯾﺪة‬ ‫ﻓﻜﺮة‬ ‫اﻟﻤﺴﺎﺣﺎت‬ ‫زﯾﺎدة‬ ‫ﺧﻼل‬ ‫ﻣﻦ‬ ‫اﻟﻤﻨﺤﺪر‬ ‫وﺟﮫ‬ ‫طﻮل‬ ‫اﻟﺘﯿﺎر‬ ‫ﺑﯿﻦ‬ ‫ﻟﻠﺘﺪاﺧﻞ‬ ‫اﻟﺴﻄﺤﯿﺔ‬ , ‫اﻟﻮﺟﮫ‬ ‫ﻋﻠﻰ‬ ‫اﻟﻤﺤﺼﻮرة‬ ‫واﻟﺪواﻣﺎت‬ ‫أﺳﻔﻠﮭﺎ‬ ‫ﺗﻘﻊ‬ ‫اﻟﺘﻲ‬ ‫اﻟﺨﺎرﺟﯿﺔ‬ ‫اﻟﺪرﺟﺎت‬ ‫وﺣﺎﻓﺎت‬ ‫ﻟﻠﺪرﺟﺎت‬ ‫اﻷﻓﻘﻲ‬ ، ‫اﻟﻤﻨﺤﺪر‬ ‫وﺟﮫ‬ ‫طﻮل‬ ‫ﻋﻠﻰ‬ ‫اﻟﺠﺮﯾﺎن‬ ‫ﺗﺪاﺧﻞ‬ ‫زﯾﺎدة‬ ‫ﻣﻊ‬. ‫ﻣﻮاﺻﻔﺎت‬ ‫اﺳﺘﺨﺪام‬ ‫إﻟﻰ‬ ‫اﻟﺪراﺳﺔ‬ ‫ھﺬه‬ ‫ﺗﮭﺪف‬) Labyrinth weir (‫ﻋﻠﯿﮫ‬ ‫ﻟﯿﻄﻠﻖ‬ ‫اﻟﻤﻨﺤﺪر‬ ‫درﺟﺎت‬ ‫ﻛﺎﻓﺔ‬ ‫ﺑﺘﺸﻜﯿﻞ‬ ‫ﺗﺴﻤﯿﺔ‬) Labyrinth stepped chute .(‫ﻧﻈﺎم‬ ‫ﻋﻠﻰ‬ ‫اﻟﺘﺠﺎرب‬ ‫اﻗﺘﺼﺮت‬) Skimming flow (‫إﺟﺮاﺋﮭﺎ‬ ‫ﺗﻢ‬ ‫اﻟﺘﻲ‬ ، ‫ﻋﻠﻰ‬ ‫ﺛﻼﺛﺔ‬ ‫ﻧﻤ‬ ‫ﺎ‬ ‫ﻣﺨﺘﺒﺮﯾ‬ ‫ذج‬ ‫ﺑ‬ ‫ﺔ‬ ‫اﻟﻤﻨﺤﺪ‬ ‫ﻣﯿﻞ‬ ‫ﺰاوﯾﺔ‬ ‫ر‬ 35 °. ‫ﺻﻨﻔﺖ‬ ‫ﺣﯿﺚ‬ ‫ﻣﺨﺘﻠﻔﺔ‬ ‫ﻧﺴﺐ‬ ‫ﻟﺜﻼﺛﺔ‬ ‫اﻟﺘﻜﺒﯿﺮ‬ ‫ﻟﻄﻮل‬ L T /W Magnification length ratio) () 1.3, 1.2, 1.1 (‫اﻟﻤﻘﺎرﻧﺔ‬ ‫ﻟﻐﺮض‬ ‫اﻟﺘﻘﻠﯿﺪي‬ ‫ﻟﻠﺸﻜﻞ‬ ‫ﻧﻤﻮذج‬ ‫إﻟﻰ‬ ‫ﺑﺎﻹﺿﺎﻓﺔ‬. ‫إرﺗﻔﺎ‬ ‫درﺟﺎت‬ ‫ﺛﻤﺎﻧﻲ‬ ‫ﻣﻦ‬ ‫ﺗﺘﻜﻮن‬ ‫اﻟﻨﻤﺎذج‬ ‫ﺟﻤﯿﻊ‬ ‫ﻣﻨﮭﺎ‬ ‫اﻟﻮاﺣﺪة‬ ‫ع‬ 4 ‫ﻗﺪره‬ ً ‫ﻛﻠﯿﺎ‬ ً ‫إرﺗﻔﺎﻋﺎ‬ ‫ﯾﻌﻄﻲ‬ ‫ﻣﻤﺎ‬ ‫ﺳﻢ‬ 32 ‫ﺳﻢ‬ ‫وﺑﻌﺮض‬ 30 ‫ﺳﻢ‬. ‫ﻋﻤﻮﻣﺎ‬ ‫اﻟﻨﺘﺎﺋﺞ‬ ‫أظﮭﺮت‬ , ‫اﻟﺸﻜﻞ‬ ‫أن‬ labyrinth ‫ﻓﻲ‬ ‫ﻟﻠﻤﻨﺤﺪر‬ ‫اﻟﺪراﺳﺔ‬ ‫ھﺬه‬ ‫اﻟﻄﺎﻗﺔ‬ ‫ﻟﺘﺸﺘﯿﺖ‬ ‫أﻋﻠﻰ‬ ‫ﻗﺎﺑﻠﯿﺔ‬ ‫ذو‬ ‫ﺑﺎﺳﺘﺨﺪام‬ ‫اﻟﻤﺴﺘﺤﺼﻠﺔ‬ ‫ﺗﻠﻚ‬ ‫ﻣﻦ‬ ‫و‬ ‫اﻟﺘﻘﻠﯿﺪي‬ ‫اﻟﺸﻜﻞ‬ ‫اﻟﺘﻜﺒﯿ‬ ‫طﻮل‬ ‫ﻧﺴﺒﺔ‬ ‫ﺑﺎزدﯾﺎد‬ ‫ﺗﺘﺰاﯾﺪ‬ ‫اﻟﻄﺎﻗﺔ‬ ‫ﺗﺸﺘﯿﺖ‬ ‫ﻛﻔﺎءة‬ ‫أن‬ ‫ﻟﻠﻨﻤﺎذج‬ ‫ﺮ‬ .