شماره مدرك :
10484
شماره راهنما :
9679
پديد آورنده :
احمدي، علي اكبر
عنوان :

بررسي عددي تاثير شكل و وزن پيستون بر روي عملكرد تونل هاي باد انفجاري فراصوت

مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
تبديل انرژي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مكانيك
سال دفاع :
1394
صفحه شمار :
شانزده، 106ص.: مصور، جدول، نمودار
استاد راهنما :
احمدرضا پيشه ور
استاد مشاور :
مهدي نيلي احمدآبادي
توصيفگر ها :
تونل ضربه , ديافراگم , موج ضربه اي
تاريخ نمايه سازي :
1394/07/11
استاد داور :
سعيد مرتضوي، محمدرضا توكلي
تاريخ ورود اطلاعات :
1396/10/04
كتابنامه :
كتابنامه
رشته تحصيلي :
مكانيك
دانشكده :
مهندسي مكانيك
كد ايرانداك :
ID9679
چكيده فارسي :
به فارسي و انگليسي
چكيده انگليسي :
298 Numerical Investigation of Effect of Shape and Weight of Piston on the Performance of a Gun Tunnel Ali Akbar Ahmadi aa ahmadi@me iut ac ir Date of Submission 2015 08 3 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Ahmad Reza Pishevar apishe@cc iut ac irAbstractAs the test gas in a gun tunnel is compressed and heated non isentropically by a light fast moving piston first consideration is the optimum piston weight Although various aspects of the influence of piston weighton gun tunnel performance have been studied it is not possible to decide from the existing literature whatpiston weight is required for various conditions The technique whereby the piston is rapidly brought to restat the end of the gun tunnel barrel and the pressure peak which results is equal in magnitude to the finalequilibrium pressure is called the equilibrium piston technique Then the equilibrium piston technique hasbeen developed to estimate equilibrium piston mass but this technique cannot give an appropriate estimatefor the piston weight Computational modeling of gun tunnel operation can enhance the understanding ofimportant ow processes and assist in the identi cation of the ow conditions that are produced by suchfacilities Such modeling can also be used as an aid in the identi cation of new operating conditions or thedesign of new or modi ed facilities In the present work the performances of the various shock and guntunnels that are built in all over the world and are being used are deeply studied in order to localization ofknowledge of design of such short duration impulse facilities For instance the 2 in and 3 in gun tunnelsare described and the performance of the 3 in gun tunnel is investigated numerically After investigation ofthe performance curve of the facility effect of weight and shape of piston are studied Pistons in differentshapes and weights are investigated for the same initial condition to optimize the gun tunnel performancewith optimization of running time of wind tunnel Numerical simulation in present work is in very goodagreement with experimental results Significant influence of the existence of a piston is shown bycomparing the gun tunnel results with results of a shock tunnel in the same initial condition and around250 increase in running time is gained Numerical results show that equilibrium piston technique is not agood way to estimate suitable piston weight and there will be a lighter piston which can increase run time ofthe gun tunnel around 60 Then a modified technique for the operation of the gun tunnel is suggestedbased on numerical results If the piston mass and the initial barrel pressure are chosen correctly then thepeak pressures associated with the gun tunnel will be eliminated Under these conditions the piston isbrought to rest with no over swing Moreover investigation of the shape of the piston shows that pistonshape has no significant effect on the performance of the gun tunnel Finally effect of imperfection in initialdiaphragm rupture as a significant loss in pressure of reservoir in end of barrel of gun tunnel wasnumerically investigated The results reveal that imperfect rupture of initial diaphragm significantly reducesthe shock wave strength shock wave speed and equilibrium pressure of reservoir At a diaphragm pressureration of 50 the equilibrium pressure decreases by 13 when diaphragm is 90 open and 27 whendiaphragm is 80 open Keywords Gun tunnel Shock tunnel Hypersonic flow Shock wave Piston Diaphrag
استاد راهنما :
احمدرضا پيشه ور
استاد مشاور :
مهدي نيلي احمدآبادي
استاد داور :
سعيد مرتضوي، محمدرضا توكلي
لينک به اين مدرک :

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