4255

4026

كارشناسي ارشد

تبديل انرژي

اصفهان : دانشگاه صنعتي اصفهان، دانشكده مكانيك

1387

هشت، 73، [II] ص. : مصور، جدول، نمودار

ص. ع. به: فارسي و انگليسي

احمد صداقت

احمد رضا پيشه ور

23/7/1387

علي اكبر عالم رجبي، محسن ثقفيان

مهندسي مكانيك

ID4026

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Abstract Accurate prediction of the rotor and fuselage interaction is essential for the design andanalysis of modern rotorcrafts Computational simulation plays an important role indecreasing expensive wind tunnel experiments In this research a method for simulatingthe helicopter flow field has investigated In this method rotor is not modelled as a rotatingbody instead its time averaged effect is added to momentum equations and the force thatrotor exerted on the fluid is replaced by source terms in momentum equations The sourceterms are distributed over computational cells in three ways uniform linear and by meansof blade element theory Wind tunnel experiments on a generic rotor and helicopter fuselage performed byNASA The flow field over this fuselage is simulated in two advance ratios and three thrustcoefficients The pressure coefficients obtained by various distributions of source terms arecompared with experimental data Uniform and linear distributions are found to beinaccurate By means of the blade element theory and trimming pitch angles pressurecoefficients are predicted more accurately Also the variation of simulated thrust of rotorin respect of its power is similar to actual rotor The model helicopter is mounted over a strut The presence of strut in thecomputational domain has not important effect on results for low speed free streams but inhigh speeds the presence of strut results in better prediction of forces and pressurecoefficients over body especially downstream of strut

احمد صداقت

احمد رضا پيشه ور

علي اكبر عالم رجبي، محسن ثقفيان