مقايسه رفتار هيدروديناميكي جريان عبوري از سرريزهاي كليد پيانويي نوعC و B ،A

Comparing the Behavior Hydrodynamics Flow Over of Type A, B, and C Piano Key Weirs

ﺳﺮرﯾﺰ ﮐﻠﯿﺪ ﭘﯿﺎﻧﻮﯾﯽ ﻧﻮع ﺟﺪﯾﺪي از ﺳﺎزه ﻫﯿﺪروﻟﯿﮑﯽ ﻫﺴﺘﻨﺪ ﮐﻪ در ﺳﺎلﻫﺎي اﺧﯿﺮ ﻣﻮردﺗﻮﺟﻪ ﻃﺮاﺣﺎن اﯾﻦ ﻧﻮع ﺳﺎزهﻫﺎ ﻗﺮارﮔﺮﻓﺘﻪاﻧﺪ. ﺗﺎﮐﻨﻮن درك ﻣﺤﺪودي از ﺗﺄﺛﯿﺮ ﭘﺎراﻣﺘﺮﻫﺎي ﻣﺨﺘﻠﻒ ﻫﻨﺪﺳﯽ ﺳﺮرﯾﺰ ﮐﻠﯿﺪ ﭘﯿﺎﻧﻮﯾﯽ ﺑﺮ روي رﻓﺘﺎر ﻫﯿﺪروﻟﯿﮑﯽ آنﻫﺎ ﺑﻪدﺳﺖآﻣﺪه اﺳﺖ. در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮماﻓﺰار FLOW-3D ﺟﺮﯾﺎن ﻣﺎﻧﺪﮔﺎر ﺑﻪﺻﻮرت ﺳﻪﺑﻌﺪي ﺑﺮ روي اﻧﻮاع ﺳﺮرﯾﺰﻫﺎي ﮐﻠﯿﺪ ﭘﯿﺎﻧﻮﯾﯽ B ،A و C ﺗﺤﻠﯿﻞ ﻋﺪدي ﺷﺪه اﺳﺖ. ﭘﺲ از ﺻﺤﺖﺳﻨﺠﯽ ﺑﺎ دادهﻫﺎي آزﻣﺎﯾﺸﮕﺎﻫﯽ، اﻟﮕﻮي ﺳﻪﺑﻌﺪي ﺟﺮﯾﺎن ﺑﺮ روي اﻧﻮاع ﺳﺮرﯾﺰﻫﺎي ﮐﻠﯿﺪ ﭘﯿﺎﻧﻮﯾﯽ B ،A و C ﺑﺮرﺳﯽﺷﺪه و ﺿﻤﻦ ارزﯾﺎﺑﯽ ﻫﯿﺪرودﯾﻨﺎﻣﯿﮑﯽ ﺟﺮﯾﺎن، ﻋﻠﻞ ﺗﻔﺎوت رﻓﺘﺎر ﺟﺮﯾﺎن ﺑﻪ ازاي ﻫﻨﺪﺳﻪﻫﺎي ﻣﺘﻔﺎوت ﺗﺒﯿﯿﻦ ﮔﺸﺘﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻠﻪ در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻣﺤﯿﻂ ﺗﺮ در ﺳﺮرﯾﺰ ﮐﻠﯿﺪ ﭘﯿﺎﻧﻮﯾﯽ ﻧﻮع B ﻧﺴﺒﺖ ﺑﻪ اﻧﻮاع A و C ﺑﯿﺸﺘﺮ ﺑﻮده و ﻟﺬا ﺳﺮﻋﺖ ﺟﺮﯾﺎن ﻧﺰدﯾﮏ ﺑﻪ ﺳﺮرﯾﺰ در اﯾﻦ ﻧﻮع ﺳﺮرﯾﺰ ﻧﺴﺒﺖ ﺑﻪ دو ﻧﻮع دﯾﮕﺮ ﮐﻤﺘﺮ ﺷﺪه ﮐﻪ ﻫﻤﯿﻦ اﻣﺮ ﻣﻨﺠﺮ ﺑﻪ ﺗﻮزﯾﻊ ﯾﮑﻨﻮاﺧﺖﺗﺮ ﺟﺮﯾﺎن ﺑﺮ روي ﺑﺨﺶﻫﺎي ﻣﺨﺘﻠﻒ ﮐﻠﯿﺪ ﺧﺮوﺟﯽ ﮔﺮدﯾﺪه و ﺑﻪﺗﺒﻊ آن ﺑﺎﻋﺚ ﮐﺎﻫﺶ اﺳﺘﻐﺮاق ﻣﻮﺿﻌﯽ و اﻓﺰاﯾﺶ درﺻﺪ ﺧﺮوﺟﯽ از ﺗﺎج ﮐﻠﯿﺪ ﺧﺮوﺟﯽ و درﻧﻬﺎﯾﺖ ﻣﻨﺘﺞ ﺑﻪ اﻓﺰاﯾﺶ ﮐﻞ دﺑﯽ ﺧﺮوﺟﯽ و ﺿﺮﯾﺐ دﺑﯽ ﺳﺮرﯾﺰ ﻧﻮع B ﻧﺴﺒﺖ ﺑﻪ اﻧﻮاع A و C ﻣﯽﮔﺮدد.

The piano key weir (PKW) is a new type of hydraulic structure that has been of great interest to designers in recent years. So far, there has been limited understanding of the effects of different geometrical parameters of these weirs on their hydraulic behavior. In the present study, steady flow on the types A, B, and C PKWs was studied numerically using the FLOW-3D numerical model. Upon software validation using the experimental data, the 3D flow pattern on the types A, B, and C PKWs was studied, and along with the evaluation of the flow hydrodynamics, the differences in the flow behavior for different geometries were explained. The results showed that the wetted perimeter of the type B PKW was more than that in the types A and C PKWs. Therefore, the velocity of the approaching flow to the type A PKW was less than that in the other two types, which led to a more uniform flow distribution over different parts of the output key and hence, decreased the local submergence and increased the outflow percent from the output key crest. This finally led to an increase in the total output discharge and the discharge coefficient of the type B PKW compared to types A and C PKWs.