شبيه سازي پرش هيدروليكي در بستر با زبري سنگريزه اي با نرم افزار FLOW-3D

Simulation of hydraulic jump on bed with gravel roughness using FLOW- 3D software

ﮐﻨﺘﺮل ﭘﺮش ﻫﯿﺪروﻟﯿﮑﯽ در ﮐﺎﻧﺎلﻫﺎي روﺑﺎز ﺑﻪ ﻣﻨﻈﻮر ﮐﺎﻫﺶ اﻧﺮژي و ﺧﺴﺎرات وارده ﺑﺮ اﺑﻨﯿﻪ ﭘﺎﯾﯿﻦدﺳﺖ ﻫﻤﻮاره از ﻣﻮﺿﻮﻋﺎت ﻣﻮرد ﺗﻮﺟﻪ ﻣﺤﻘﻘﯿﻦ ﺑﻮده اﺳﺖ. ﯾﮑﯽ از ﻣﻬﻢﺗﺮﯾﻦ ﻣﻮارد در اﯾﻦ زﻣﯿﻨﻪ ﺳﺎﺧﺖ اﻧﻮاع ﺣﻮﺿﭽﻪ آراﻣﺶ ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ ﻋﻮاﻣﻞ اﻗﺘﺼﺎدي و ﺳﻬﻮﻟﺖ اﺣﺪاث ﻣﯽﺑﺎﺷﺪ. ﺑﻪ ﻫﻤﯿﻦ ﺧﺎﻃﺮ اﻏﻠﺐ ﻗﺒﻞ از ﺗﺼﻤﯿﻢﮔﯿﺮي ﺑﺮاي اﺣﺪاث ﺣﻮﺿﭽﻪ، ﺷﺒﯿﻪﺳﺎزي ﺟﻬﺖ ﭘﯿﺶﺑﯿﻨﯽ رﻓﺘﺎر ﭘﺮش در ﺣﺎﻻت ﻣﺨﺘﻠﻒ اﻧﺠﺎم ﻣﯽﮔﺮدد. ﯾﮑﯽ از روشﻫﺎي ﺟﺪﯾﺪ ﮐﻨﺘﺮل ﭘﺮش در ﮐﺎﻧﺎلﻫﺎ، اﺣﺪاث ﺣﻮﺿﭽﻪ آراﻣﺶ ﺑﺎ زﺑﺮي ﺳﻨﮓرﯾﺰهاي اﺳﺖ. ﻟﺬا در اﯾﻦ ﺗﺤﻘﯿﻖ ﺷﺒﯿﻪﺳﺎزي ﭘﺮش ﺑﺮ روي ﺑﺴﺘﺮ ﺑﺪون ﺷﯿﺐ و ﺑﺎ زﺑﺮي ﺳﻨﮓرﯾﺰهاي در اﻋﺪاد ﻓﺮود اوﻟﯿﻪ 4/9ﺗﺎ 7/8، در ﭼﻬﺎر زﺑﺮي ﻣﺘﻔﺎوت ﺻﻔﺮ، 1، 4و 10ﻣﯿﻠﯽ ﻣﺘﺮ ﺑﺎ ﻧﺮماﻓﺰار FLOW-3Dاﻧﺠﺎم ﺷﺪ. در اداﻣﻪ ﻧﺘﺎﯾﺞ ﺑﺎ دادهﻫﺎي آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﻘﺎﯾﺴﻪ ﮔﺮدﯾﺪﻧﺪ. ﺑﺮاﺳﺎس ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه، ﺑﯿﺶﺗﺮﯾﻦ و ﮐﻢﺗﺮﯾﻦ ﺧﻄﺎ در ﺗﺨﻤﯿﻦ ﻋﻤﻖ اوﻟﯿﻪ ﺑﻪ ﺗﺮﺗﯿﺐ در ﺑﺴﺘﺮ ﺑﺪون زﺑﺮي و ﺑﺎ زﺑﺮي 4 ﻣﯿﻠﯽﻣﺘﺮ و ﺑﯿﺶﺗﺮﯾﻦ و ﮐﻢﺗﺮﯾﻦ ﺧﻄﺎ در ﺗﺨﻤﯿﻦ ﻋﻤﻖ ﺛﺎﻧﻮﯾﻪ ﺑﻪ ﺗﺮﺗﯿﺐ در ﺑﺴﺘﺮ ﺑﺎ زﺑﺮي 4ﻣﯿﻠﯽ ﻣﺘﺮ و ﺑﺴﺘﺮ ﺑﺪون زﺑﺮي ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﯿﺶ ﺗﺮﯾﻦ و ﮐﻢﺗﺮﯾﻦ ﺧﻄﺎ در ﺗﺨﻤﯿﻦ ﻃﻮل ﭘﺮش ﺑﻪ ﺮﺗﯿﺐ در ﺑﺴﺘﺮ ﺑﺎ زﺑﺮي 4 ﻣﯿﻠﯽﻣﺘﺮ و ﺑﺴﺘﺮ ﺑﺪون زﺑﺮي رخ داده اﺳﺖ.

Hydraulic jump control in open channels to reduce energy and damage to downstream constructions has always been a topic of researchers’ interests. One of the most important cases in this field is the build of various types of stilling basin considering economic factors and ease of construction. For this reason, jump simulations are often performed before deciding to construct a stilling basin to predict jump behavior in different conditions. One of the new methods of jump control in channels is the construction of a stilling basin with gravel roughness. Therefore, in this research, jump simulation on a non-sloped bed with gravel roughness in the initial Froude numbers of 4.9 to 7.8 and four different roughness’s diameters of zero, 1, 4 and 10 mm was performed using FLOW-3D software and results were compared with experimental results. Results showed that the maximum and minimum errors in estimating the initial depth were determined on the bed without roughness and with diameter roughness of 4 mm and the highest and lowest errors in estimating the sequent depth were determined on the bed with diameter roughness of 4 mm and the bed without roughness, respectively. Moreover, the highest and lowest errors in estimating the jump length occurred in the bed with a diameter roughness of 4 mm and the bed without roughness, respectively.