Investigation of rotor rotor interactions for two helicopters in forward flight using free vortex wake methodology

2010-07-01
Tonkal, Ozan Çağrı
Pehlivan, Sercan
Sezer Uzol, Nilay
İşler, Veysi
This paper presents an investigation of the aerodynamic interactions between two UH-1H helicopter rotors in forward flight. The wake flow structure and performance characteristics of the rotors are investigated when the rear rotor is operating within the wake of the front rotor. A 3-D unsteady vortex-panel method potential flow solver based on a free-vortex-wake methodology is used for this purpose. The solver is validated using the experimental data from the Caradonna-Tung experiments. The interactional analyses are performed for 10 different positions of the rear rotor with respect to the front rotor. The wake of the front rotor, which is generated due to the mutual interactions of the wake and tip vortices, is significantly asymmetric and non-uniform. Therefore the rear rotor operates within a complex and vortical free-stream flow. The interaction of the incoming wake flow and the rear rotor generates a large, asymmetric wake region downstream of the rear rotor. The wake-rotor interactions cause substantial variations in the forces generated by the rear rotor. These variations also depend on the lateral location of the rear rotor with respect to the front one
AIAA 40th Fluid Dynamics Conference and Exhibit,( 28 Haziran - 01 Temmuz 2010)

Suggestions

Investigation of rotor wake interactions in helicopters using 3d unsteady free vortex wake methodology
Yemenici, Öznur; Uzol, Oğuz; Department of Aerospace Engineering (2010)
This thesis focuses on developing and examining the capabilities of a new in-house aerodynamic analysis tool, AeroSIM+, and investigating rotor-rotor aerodynamic interactions for two helicopters, one behind the other in forward flight. AeroSIM+ is a 3-D unsteady vortex panel method potential flow solver based on a free vortex wake methodology. Validation of the results with the experimental data is performed using the Caradonna-Tung hovering rotor test case. AeroSIM+ code is improved for forward flight cond...
Vortex Formation and Force Generation Mechanisms of the DelFly II in Hovering Flight
Tenaglia, A; Perçin, Mustafa; Van Oudheusden, Bas W.; Deng, Shuanghou; Remes, Bart (2014-08-12)
This paper addresses the unsteady aerodynamic mechanisms in the hovering flight of the DelFly II flapping-wing Micro Aerial Vehicle (MAV). Stereoscopic Particle Image Velocimetry (Stereo-PIV) were carried out around the wings at a high framing rate. Thrust-force was measured to investigate the relation between the vortex dynamics and the aerodynamic force generation. The results reveal that the Leading-Edge-Vortex (LEV), as well as the high flexibility of the wings, have a major effect on thrust generation....
A Computational analysis on rotor-propeller arm interaction in hovering flight
Yener, Serkan.; Perçin, Mustafa; Department of Aerospace Engineering (2019)
This study presents a computational analysis on the interaction between rotor and different rotor frame-arm geometries in hovering flight. The influence of the frame arm on the aerodynamic performance of the rotor is assessed by using commercially available computational fluid dynamics (CFD) solver software ANSYS Inc. Fluent 17. Numerical results are validated for hovering and forward vertical climb flight conditions with thrust and torque measurements conducted on a 16x4 carbon fiber propeller. The thrust ...
Experimental investigation of tip anhedral effects on the aerodynamics of a model helicopter rotor in hover
Uluocak, Sinem; Perçin, Mustafa; Uzol, Oğuz (2021-06-01)
This study experimentally investigates the effects of tip anhedral on the rotor aerodynamic performance and the tip vortex characteristics in hovering flight. A five-bladed scaled helicopter rotor with blades that have either rectangular (baseline) or anhedral tip geometries was used as the experimental model. Thrust and torque measurements were performed at the tip Mach numbers (Mtip) of 0.3 and 0.4 at five different pitch angles. In addition, flow field measurements via phase-locked particle image velocim...
Experimental Investigation of Aerodynamics of Flapping-Wing Micro-Air-Vehicle by Force and Flow-Field Measurements
Deng, Shuanghou; Perçin, Mustafa; van Oudheusden, Bas (2016-02-01)
This study explores the aerodynamic characteristics of a flapping-wing micro aerial vehicle (MAV) in hovering configuration by means of force and flowfield measurements. The effects of flapping frequency and wing geometry on force generation were examined using a miniature six-component force sensor. Additional high-speed imaging allowed identification of the notable different deformation characteristics of the flexible wings under vacuum condition in comparison to their behavior in air, illustrating the re...
Citation Formats
O. Ç. Tonkal, S. Pehlivan, N. Sezer Uzol, and V. İşler, “Investigation of rotor rotor interactions for two helicopters in forward flight using free vortex wake methodology,” presented at the AIAA 40th Fluid Dynamics Conference and Exhibit,( 28 Haziran - 01 Temmuz 2010), Chicago, Illinois, Amerika Birleşik Devletleri, 2010, Accessed: 00, 2021. [Online]. Available: http://arc.aiaa.org/doi/abs/10.2514/6.2010-4558.