PARABOLİK SİVRİLME DAĞILIMININ BURULMASIZ BİR HELİKOPTER ROTOR PALİ ÜZERİNDEKİ ETKİSİNİN HAD ANALİZİ

Bir helikopter rotor palinin açıklığı boyunca parabolik olarak değişen sivrilme dağılımının etkisi rotor itkisi, torku ve verim ölçüsü cinsinden incelenmiştir. Birçok farklı maksimum veter uzunluğu değerleri kullanılmıştır. Reynolds Ortalamalı Navier-Stokes hesaplamaları NUMECA International tarafından geliştirilmiş olan FINE/Turbo akış çözücüsü ile yapılmıştır. Edi viskozitesini hesaplamak için Spalart-Allmaras türbülans modeli kullanılmıştır. Referans pali olarak Caradonna-Tung rotor pali seçilmiştir. Referans pal ile aynı planform alana sahip olacak şekilde muhtelif kanat açıklığı konumlarında maksimum veter uzunluğunun girdi olarak verilmesi ile farklı pal şekilleri elde edilmiştir. Üç eniyi durum gözlenmiştir: maksimum verim ölçüsü, referans verim ölçüsünde maksimum itki, referans itkide maksimum verim ölçüsü. Bu üç eniyi durum, maksimum veter uzunluğunun referans veterin 1.3 katı olduğu koşulda görülmüştür.

CFD ANALYSIS OF THE EFFECT OF PARABOLIC TAPER DISTRIBUTION OF AN UNTWISTED HELICOPTER ROTOR BLADE

The effect of parabolic taper distribution along the span of a helicopter rotor blade is analyzed in terms of therotor thrust, torque and Figure of Merit. Various maximum chord length values are investigated. The ReynoldsAveraged Navier-Stokes computations are done using the FINE/Turbo flow solver developed by NUMECAInternational. The Spalart-Allmaras turbulence model is used to calculate the eddy viscosity. The baseline bladeis selected as the Caradonna-Tung rotor blade. Different blade shapes were generated by setting the maximumchord length at different spanwise locations for the same planform area as the baseline blade. Three optimumcases are observed: maximum Figure of Merit, maximum thrust for the baseline Figure of Merit and maximumFigure of Merit for the baseline thrust. Those optimum cases are noticed when the maximum chord length is 1.3times the baseline blade chord length.

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