8986

8331

كارشناسي ارشد

تبديل انرژي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1392

پانزده،93ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مهدي نيلي

حسين احمدي كيا

13/3/93

محمد رضا توكلي نژاد، احمد صداقت

مهندسي مكانيك

ID8331

Hydrodynamic Analysis of Unsteady Flow for an Underwater Projectile Mohammad Hassan Ahmadzadeh Jazi Hassan ahmadzadeh@gmail com Feb 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Mahdi Nili Ahmadabadi m nili@cc iut ac irAdvisor Dr Hosein Ahmadikia ahmadikia@yahoo comAbstractEjecting a projectile with compressed air under water has a complicated mechanism and includes severalparameters Here thermodynamic hydrodynamic and dynamic equations governing the discharging processof the compressed air are derived Having solved the equation set effects of effective parameters in theprojection system are studied The result shows that about 90 of behavior of the projection process isaffected by opening and closing the compressed air injection valve Fire Valve Therefore it is necessary torelate the changes of fire valve throat area to the time for different depths as a function whose results areconsistent with experimental data of a real system Items such as pressure of launcher tube and projectilespeed at the moment of jumping out of the tube the maximum allowable acceleration exerted on theprojectile the maximum allowable pressure inside launcher tube and the residual pressure inside the cylinderof compressed air At the moment of stopping air injection are verification parameters based on real data According to these parameters the function of valve opening and closing time are estimated in a polynomialand cosine form respectively Coefficients of these functions are computed for five depths of 10 50 100 150 200 meters Optimization in such systems is a time consuming and troublesome process Havinganalyzed the compressed air launcher it is needed to validate the assumptions by means of CFD simulationin Fluent Software during some phases Such CFD simulation by the Fluent software is time consuming Therefore the Projection parameters are studied just in depth of 100 meters of water To do this thenumerical results of axisymmetric simulation accomplished by Fluent Software are compared with theresults of system equations solution Then a 3D numerical simulation is done in the Fluent software toinvestigate the 3D launcher model Finally some intermediate results of 3D model are presented Key words Positive discharge system Air injection valve Poppet valve Underwater Launch control Fluent Simulation

مهدي نيلي

حسين احمدي كيا

محمد رضا توكلي نژاد، احمد صداقت