23826

مطالعه عددي تاثير شكل هندسي جداره بهبوده دهنده با پره‌هاي متعاقب بر ميزان بهبود حاشيه امن كمپرسور جريان محوري با عدم پوشش محوري 53.5 درصد

كارشناسي ارشد

مهندسي مكانيك

1396

آبان 1399

دكتر محمد اخلاقي

دانشكده مهندسي مكانيك

در اﯾﻦ ﭘﺎﯾﺎن ﻧﺎﻣﻪ ،ﺗﺎﺛﯿﺮات ﻣﺨﺘﻠﻒ ﺑﻪ ﮐﺎرﮔﯿﺮي يك روش ﻏﯿﺮ ﻓﻌﺎل ﺑﺮاي ﺟﻠﻮﮔﯿﺮي و ﺑﺎ ﺗﺎﺧﯿﺮ اﻧﺪاﺧﺘﻦ ﭘﺪﯾﺪه سكته در ﮐﻤﭙﺮﺳﻮر ﺟﺮﯾﺎن ﻣﺤﻮري ﻣﻄﺎﻟﻌﻪ ﺷﺪه اﺳﺖ. روش ﻏﯿﺮ فعالي ﮐﻪ ﺑﺮاي ﮐﻨﺘﺮل سكته در اﯾﻦ رﺳﺎﻟﻪ بررسي ﺷﺪه اﺳﺖ، اﺳﺘﻔﺎده از ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﺣﻔﺮه ﺑﺎزﮔﺮدش ﺑﺎ ﭘﺮه ﻫﺎي ﻣﺘﻌﺎﻗﺐ ﺑﻮده اﺳﺖ. ﭘﻨﺞ ﻫﻨﺪﺳﻪ ﻣﺨﺘﻠﻒ از ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻣﻄﺎﻟﻌﻪ ﺷﺪ و ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ اﺳﺘﻔﺎده از ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻧﯿﻤﻪ داﯾﺮوي و ﻧﯿﻤﻪ ﺑﯿﻀﻮي مي‌تواند ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﺣﺎﺷﯿﻪ اﻣﻦ را از ﻣﻨﻈﺮ ﺿﺮﯾﺐ ﺟﺮﯾﺎن، ﺿﺮﯾﺐ اﻓﺰاﯾﺶ ﻓﺸﺎر ﮐﻞ ﺑﻪ ﮐﻞ، و ﺿﺮﯾﺐ اﻓﺰاﯾﺶ ﻓﺸﺎر ﮐﻞ ﺑﻪ استاتيك ﺑﺮاي ﮐﻤﭙﺮﺳﻮر اﯾﺠﺎد ﮐﻨﺪ. ﺣﺎﺷﯿﻪ اﻣﻦ ﮐﻤﭙﺮﺳﻮر ﺑﺎ ﺟﺪاره ﻧﯿﻤﻪ ﺑﯿﻀﻮي و ﻧﯿﻤﻪ داﯾﺮوي (ﺑﺮ ﺣﺴﺐ ﺿﺮﯾﺐ ﺟﺮﯾﺎن) ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 35٫3 و 34٫9 ﺑﺪﺳﺖ آﻣﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﺑﺎ بررسي ﻣﯿﺰان ﺑﻬﺒﻮد ﺣﺎﺷﯿﻪ اﻣﻦ ﻣﺸﺨﺺ ﮔﺮدﯾﺪ ﮐﻪ ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻧﯿﻤﻪ داﯾﺮوي و ﻧﯿﻤﻪ ﺑﯿﻀﻮي ﺑﯿﺸﺘﺮﯾﻦ ﻣﻘﺎدﯾﺮ ﺑﻬﺒﻮد ﺣﺎﺷﯿﻪ اﻣﻦ ﺑﺮ ﺣﺴﺐ ﺿﺮﯾﺐ ﺟﺮﯾﺎن را ﻧﯿﺰ ﺑﻪ ﺧﻮد اﺧﺘﺼﺎص داده اﻧﺪ ﮐﻪ اﯾﻦ ﻣﻘﺎدﯾﺮ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 17٫91 و 17٫15 درﺻﺪ ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﺑﺎ اﯾﻦ وﺟﻮد ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻧﯿﻤﻪ داﯾﺮوي ارﺟﺤﯿﺖ چنداني ﻧﺴﺒﺖ ﺑﻪ ﮐﻤﭙﺮﺳﻮر ﺑﺪون ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه از ﻣﻨﻈﺮ اﻓﺰاﯾﺶ ﺿﺮﯾﺐ ﮐﻞ ﺑﻪ ﮐﻞ ﻧﺪاﺷﺖ. حتي اﺳﺘﻔﺎده از ﺟﺪاره ﻫﺎي ﺑﻬﺒﻮد دﻫﻨﺪه ﻧﯿﻤﻪ ﻗﻠﺒﯽ ﻣﺴﺘﻘﯿﻢ و ﻣﻌﮑﻮس ﺑﺎﻋﺚ ﮐﺎﻫﺶ ﺑﯿﺸﯿﻨﻪ ﻣﻘﺪار ﺿﺮﯾﺐ اﻓﺰاﯾﺶ ﻓﺸﺎر ﮐﻞ ﺑﻪ ﮐﻞ در ﻣﻘﺎﯾﺴﻪ ﺑﺎ ﮐﻤﭙﺮﺳﻮر ﺑﺪون ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﺷﺪ. ﺑﯿﺸﯿﻨﻪ ﻣﻘﺪار ﺿﺮﯾﺐ اﻓﺰاﯾﺶ ﻓﺸﺎر ﮐﻞ ﺑﻪ استاتيك در ﺻﻮرت اﺳﺘﻔﺎده از ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻫﻤﯿﺸﻪ اﻓﺰاﯾﺶ ﭘﯿﺪا ﮐﺮد. ﺟﺪاره ﻧﯿﻤﻪ ﺑﯿﻀﻮي، ﺑﯿﺸﺘﺮﯾﻦ ﺑﻬﺒﻮد در ﺿﺮﯾﺐ اﻓﺰاﯾﺶ ﻓﺸﺎر ﮐﻞ ﺑﻪ استاتيك را ﺗﺠﺮﯾﻪ ﮐﺮد و ﭘﺲ از آن ﺟﺪاره ﻫﺎي ﻧﯿﻤﻪ داﯾﻮري، ﺗﯿﻮﺑﯽ، ﻗﻠﺒﯽ ﻣﺴﺘﻘﯿﻢ و ﻗﻠﺒﯽ ﻣﻌﮑﻮس ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻣﺪل ﺗﻮﺳﻌﻪ داده ﺷﺪه ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻗﺎﺑﻞ توجهي در ﻣﻮرد ﺑﻬﺒﻮد ﺑﺎزده ﮐﻤﭙﺮﺳﻮر در اﺛﺮ اﺳﺘﻔﺎده از ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه اراﺋﻪ داده اﺳﺖ. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺟﺪاره ﻧﯿﻤﻪ ﺑﯿﻀﻮي، ﻧﯿﻤﻪ داﯾﺮوي و ﻧﯿﻤﻪ ﺗﯿﻮﺑﯽ ﺗﻮاﻧﺴﺘﻨﺪ ﻣﻘﺎدﯾﺮ ﺑﺎزده ﮐﻞ ﺑﻪ ﮐﻞ ﺑﯿﺸﺘﺮي ﻧﺴﺒﺖ ﺑﻪ ﮐﻤﭙﺮﺳﻮر ﺑﺪون ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﭘﯿﺶ بيني ﮐﻨﻨﺪ. در اﯾﻦ ﺧﺼﻮص ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه ﻧﯿﻤﻪ ﺑﯿﻀﻮي ﺑﺎ 1٫17 درﺻﺪ، ﺑﯿﺸﺘﺮﯾﻦ ﺑﻬﺒﻮد ﺑﺎزده را داﺷﺘﻪ اﺳﺖ. ﭘﺲ از آن، ﺟﺪاره ﻫﺎي ﻧﯿﻤﻪ داﯾﺮوي و ﻧﯿﻤﻪ ﺗﯿﻮﺑﯽ ﺑﺎ 0٫49 و 0٫29 درﺻﺪ ﻗﺮار ﮔﺮﻓﺘﻪ اﻧﺪ. ﻧﮑﺘﻪ ﺟﺎﻟﺐ ﺗﻮﺟﻪ آن اﺳﺖ ﮐﻪ ﻧﺘﺎﯾﺞ ديگر ﻣﺤﻘﻘﯿﻦ حاكي از ﺗﺨﺮﯾﺐ ﺑﺎزده ﮐﻤﭙﺮﺳﻮر در اﺛﺮ اﺳﺘﻔﺎده از اﻧﻮاع دﯾͽﺮ ﺟﺪاره ﺑﻬﺒﻮد دﻫﻨﺪه (ﺷﯿﺎر محيطي و شكاف ﻣﺤﻮري) اﺳﺖ.

1400/03/18

Numerical analysis of effect of vane recess casing treatment geometry on stall margin improvement of an axial-flow compressor with rotor axial exposure of 53.5%

11/21/2021 12:00:00 AM

In this dissertation, various effects of employing a passive stall delay method on the performance of a compressor have been investigated. A recirculation cavity casing treatment was adopted as the passive stall delay method. Five casing treatment shapes have been studied and the model results showed that semi-circular and semi-elliptical shapes have the highest stall margin values. Having analyzed the Stall Margin Improvement (SMI) values for different casing treatment shapes, it was concluded that semi-circular and semi-elliptical shapes have also the best SMI values based on flow coefficient, which are 17.91% and 17.15% respectively. Despite this, the total-to-total pressure rise coefficient of semi-circular case was not greatly improved comparing to the solid casing compressor. Semi-hearted and Semi-hearted reversed configurations have even smaller maximum total-to-total pressure rise coefficients in comparison with solid casing. The maximum total-to-static pressure rise coefficient was always improved for all of the studied configurations. Semi-elliptical configuration has the best performance in this regard followed by semi-circular, semi-tubular, semi-hearted, and semi-hearted reversed. The developed model for casing treatment leads to another important outcome concerning the value of compressor efficiency. Based on the results of the model, semi-elliptical, semi-circular, and semi-tubular configurations led to higher total-to-total efficiency values comparing with solid casing compressor. The value of efficiency improvement was calculated to be 1.17%, 0.49% and 0.29% for these three cases, respectively. It is important to note that the results of other researchers show that other types of casing treatments (axial slot & circumferential groove) would generally sacrifice the efficiency of the compressor.

كمپرسور محوري , سكته و خفقان , جداره بهبود دهنده , كنترل سكته

axial compressor , stall and surge , casing treatment , stall control