بررسي آزمايشگاهي ضريب ‌دبي در سازه تركيبي سرريز- دريچه با ايجاد كنگره‌هاي مثلثي شكل در بال سرريز

Laboratory study of flow coefficient at the spillway - gate composite structure by creating triangular congresses in the spillway wing

ﺗﺮﮐﯿﺐ ﺳــﺮرﯾﺰ ﺑﺎ درﯾﭽﻪ ﺑﺎﻋﺚ اﯾﺠﺎد ﺗﻐﯿﯿﺮاﺗﯽ در ﺿــﺮﯾﺐدﺑﯽ ﻣﯽﮔﺮدد. ﺳــﺎزه ﺗﺮﮐﯿﺒﯽ ﺳــﺮرﯾﺰ- درﯾﭽﻪ ﺑﻪ دو ﻣﻨﻈﻮر اﻧﺪازهﮔﯿﺮي دﺑﯽ ﺟﺮﯾﺎن و ﺟﻠﻮﮔﯿﺮي از اﻧﺒﺎﺷـﺘﻪ ﺷـﺪن رﺳـﻮﺑﺎت در زﻣﺴـﺘﺎن ﮐﻪ آب ﮔﻞآﻟﻮد ﻣﯽﺑﺎﺷـﺪ ، در ﭘﺸـﺖ ﺳـﺮرﯾﺰ ﺑﮑﺎر ﻣﯽرود. در اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ ﻃﺮاﺣﯽ و ﺳـﺎﺧﺖ ﭼﻬﺎر ﻣﺪل ﺗﺮﮐﯿﺒﯽ ﺳـﺮرﯾﺰﻫﺎي ﮐﻨﮕﺮهاي ﻣﺮﺑﻌﯽ ﻫﻤﺮاه ﺑﺎ درﯾﭽﻪ ، ﺗﺎﺛﯿﺮ ﭘﺎراﻣﺘﺮﻫﺎي ﻫﯿﺪروﻟﯿﮑﯽ از ﺟﻤﻠﻪ ﻓﺸـﺎر آب روي ﺳـﺮرﯾﺰ )h( و ﭘﺎراﻣﺘﺮﻫﺎي ﻫﻨﺪﺳـﯽ از ﺟﻤﻠﻪ ارﺗﻔﺎع روزﻧﻪ )a( ﻋﺮض درﯾﭽﻪ )b( و ﻓﺎﺻـﻠﻪ ﺑﯿﻦ ﺑﺎﻻي روزﻧﻪ ﺗﺎ راس ﻣﺜﻠﺚ )y(، ﺑﺮ ﺿـﺮﯾﺐدﺑﯽ ﻣﻮرد ﺑﺮرﺳـﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸـﺎت ﻧﺸـﺎن داد ﮐﻪ ﺿـﺮﯾﺐدﺑﯽ ﺑﺎ اﻓﺰاﯾﺶ ﻧﺴـﺒﺖﻫﺎيh/b ،h/y و h/a ﺑﯽﺑﻌﺪ ﮐﺎﻫﺶ ﻣﯽﯾﺎﺑﺪ و ﻣﺪل ﺗﺮﮐﯿﺒﯽ ﺑﯿﺸـﺘﺮ ﻋﻤﻠﮑﺮدي ﺷـﺒﯿﻪ ﺑﻪ درﯾﭽﻪ دارد. ﻫﻤﭽﻨﯿﻦ راﺑﻄﻪاي ﺟﻬﺖ ﺗﺨﻤﯿﻦ ﺿـﺮﯾﺐدﺑﯽ ﺟﺮﯾﺎن ﺑﺎ ﺿـﺮﯾﺐ ﻫﻤﺒﺴـﺘﮕﯽ 0/98 اراﺋﻪ ﺷـﺪ. ﺗﺤﻠﯿﻞ ﺣﺴـﺎﺳـﯿﺖ راﺑﻄﻪ ﻧﺸـﺎن داد ﮐﻪ ﻧﺴـﺒﺖ ﺑﯽﺑﻌﺪ h/y داراي ﺑﯿﺸـﺘﺮﯾﻦ ﺣﺴـﺎﺳـﯿﺖ و ﺗﺎﺛﯿﺮ را دارا ﻣﯽﺑﺎﺷـﺪ و در ﻧﻬﺎﯾﺖ اﯾﻨﮑﻪ در ﺟﺎﻫﺎﯾﯽ ﮐﻪ ﻣﺤﺪودﯾﺖ ﻋﺮض ﺳـﺮرﯾﺰ وﺟﻮد دارد ﺑﺎ اﺟﺮاي اﯾﻦ ﻧﻮع ﺳـﺮرﯾﺰﻫﺎ و از ﻫﻤﻪ ﻣﻬﻢﺗﺮ ﺑﺎ اﯾﺠﺎد درﯾﭽﻪ در ﺑﺪﻧﻪ ﺳـﺮرﯾﺰ ﯾﻌﻨﯽ ﺑﻪ ﺣﺎﻟﺖ ﺗﺮﮐﯿﺒﯽ ﻣﯿﺰان دﺑﯽ ﻋﺒﻮري ﻓﺰاﯾﺶ ﺧﻮاﻫﺪ ﯾﺎﻓﺖ ﮐﻪ ﺑﺴﯿﺎر ﺣﺎﺋﺰ اﻫﻤﯿﺖ ﻣﯽﺑﺎﺷﺪ.

Combining the overflow with the gate causes changes in the discharge coefficient. Spillway- gate composite structure is used behind the overflow to measure the flow rate and prevent the accumulation of sediment in winter when the water is muddy. In this research, by designing and constructing four combined models of square congress spillways with gates, the effect of hydraulic parameters such as water pressure on the spillway (h) and geometric parameters such as gate height (a), gate width (b) and the distance between the top Apertures up to the vertex of triangle (y) were examined on the coefficient of flow. The experimental results showed that the discharge coefficient decreases with increasing proportions of h/y, h/b and h/a and the hybrid model has more gates -like performance. Also, a relation was presented to estimate the flow rate R2 = 0.98. Sensitivity analysis of the relationship showed that the dimensionless ratio h/y has the highest sensitivity and effect. an‎d finally, in places where we have a limit on the width of the spillway, by implementing these types of overflows and, most importantly, by creating a valve in the body of the overflow, that is, in combination, the amount of flow will increase, which is very important.