Numerical Investigation of Propeller - Frame Arm Interaction in Hovering Flight

This study explores the interaction between a propeller and various frame arm geometries, which are typically used in multi-rotor applications. The influence of the arm on the propulsive performance of the propeller is investigated by using commercial computational fluid dynamics (CFD) solver ANSYS Fluent 17 in hovering flight. CFD results are validated for hover and vertical climb conditions with thrust and torque measurements conducted on a 16x4 carbon fiber propeller. Four different arm geometries (i.e., an Eppler arm, a cylindrical tube, a square tube, and a slotted square tube) are studied to investigate their effect on the propulsive performance of the propeller and the complete propeller-arm configuration. Regardless of the geometry, the arm enhances the thrust generation of the propeller for all propeller-arm distances considered in this study. However, the total thrust of the propeller-arm configuration is smaller than the single propeller case due to drag exerting on the arm. In this respect, the Eppler arm configuration has the best performance in terms of the total force generation due to relatively low drag of the Eppler profile. The square arm configuration yields the highest thrust generation and propulsive efficiency for the propeller despite having the lowest total force generation.

Pervane ve Pervane Kolu Arasındaki Etkileşimin Askıda Uçuş Durumu için Hesaplamalı Yöntemle İncelenmesi

Bu çalışmada, çoğunlukla çoklu rotor uygulamalarında kullanılan pervane ve çeşitli pervane kolu tasarımları arasındaki etkileşim askıda uçuş durumunda incelenmektedir. Pervane kolunun pervanenin itme performansı üzerindeki etkisi, ticari bir hesaplamalı akışkanlar dinamiği (HAD) çözücü yazılımı olan ANSYS Fluent 17 ile incelenmiştir. Elde edilen HAD sonuçları, askıda ve dikey uçuş durumlarında bir 16x4 karbon fiber pervane kullanılarak yapılan itme ve tork test ölçümleri ile doğrulanmıştır. Dört farklı pervane kol geometrisinin (Eppler tipi, silindirik boru, kare boru, ve oluklu kare boru) pervane ve pervane-koldan oluşan bütün yapı üzerindeki etkileri çalışılmıştır. Pervane kolunun varlığı, geometri farkı olmaksızın çalışmada dikkate alınan tüm pervane kolu mesafeleri için pervane itkisini arttırmaktadır. Bununla birlikte, pervane kolunu da içeren konfigürasyonun toplam itme kuvveti, rotor koluna uygulanan sürüklemeden dolayı sadece pervanenin olduğu duruma göre daha düşüktür. Bu açıdan, Eppler kolu ile yapılan konfigürasyon, toplam itme kuvveti üretimi açısından en iyi performansa sahiptir. Kare kesitli kol durumunda ise konfiguürasyonun toplam kuvveti en küçük olsa da pervanenin ürettiği itki ve itki verimi en yüksektir.

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