Rotor Blade Tip Shape Effects on Performance and Control Loads from Full-Scale Wind Tunnel Testing

Stroub, Robert H.; Rabbott, J. P.; Niebanck, Charles F.

doi:10.4050/jahs.24.28

Cited by 7 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The full-scale S-76 rotor was tested by Johnson [52] Stroub [53], whereas blade vibratory loads and noise were investigated by Jepson [54]. Comparison of the performance of the full-scale with the 1/5 model-scale and theoretical calculations were conducted by Balch [55].…”

Section: Full-scale S-76 Rotor Bladementioning

confidence: 99%

Accurate Predictions of Rotor Hover Performance at Low and High Disc Loadings

García

Barakos

2018

Journal of Aircraft

View full text Add to dashboard Cite

This paper presents evidence on the ability of modern CFD methods to accurately predict hover performance of rotors with modest computer resources. The paper uses two well-studied blades, the S-76 main rotor blade and the XV-15 tiltrotor blade. The results are compared with experiments and show that the performance is well predicted. In addition, the employed Computational Fluid Dynamics method was able to capture the effects of the tip Mach number, tip shape, blade aeroelasticity, and flow transition on the performance of the blade as well as on the wake structure and the rotor acoustics.

show abstract

Section: Full-scale S-76 Rotor Bladementioning

confidence: 99%

Accurate Predictions of Rotor Hover Performance at Low and High Disc Loadings

García

Barakos

2018

Journal of Aircraft

View full text Add to dashboard Cite

show abstract

“…Like the model scale, it was found that the swept tapered tip had the better performance in forward flight mainly due to a lower power required. A further discussion of the rotor performance was reported by Stroub (53) , whereas blade vibratory loads and noise were investigated by Jepson (8) . This campaign of test was accomplished with a comparison of the full-scale to 1/5 model-scale, flight test results and theoretical calculations conducted by Balch (54) .…”

Section: Full-scale S-76 Rotor Bladementioning

confidence: 99%

CFD analysis of hover performance of rotors at full- and model-scale conditions

Barakos

García

2016

Aeronaut. j.

View full text Add to dashboard Cite

Analysis of the performance of a 1/4.71 model-scale and full-scale Sikorsky S-76 main rotor in hover is presented using the multi-block CFD solver of Glasgow University. For the model-scale blade, three different tip shapes were compared for a range of collective pitch and tip Mach numbers. It was found that the anhedral tip provided the highest Figure of Merit. Rigid and elastic full-scale S-76 rotor blades were investigated using a loosely coupled CFD/CSD method. Results showed that aeroelastic effects were more significant for high thrust cases. Finally, an acoustic study was performed in the tippath-plane of both rotors, showing good agreement in the thickness and loading noise with the theory.For the anhedral tip of the model-scale blade, a reduction of 5% of the noise level was predicted.The overall good agreement with the theory and experimental data demonstrated the capability of the present CFD method to predict rotor flows accurately.Keywords : CFD, S76, Hover, Tip-shape.

show abstract

“…16 (2), 295-310 (2015) (CFD). Unlike a fixed-wing aircraft, the tip vortex remains near the rotor blades, which affects the blade aerodynamic loading and also induces a highly impulsive noise.…”

Section: Introductionmentioning

confidence: 99%

“…The shape of the blade tip of a helicopter rotor is known to have a considerable impact on the overall performance of the rotor, blade airloads, noise, and tip-vortex trajectory. Experimental and computational studies have been carried out to improve the hover performance according to variations in the rotor tip shapes [1][2][3][4][5][6]. Of the various blade configurations that are possible, tapered, swept and anhedral tip shapes have been widely used for modern helicopters.…”

Section: Introductionmentioning

confidence: 99%

“…A tapered tip improves the rotor efficiency, such as the Figure of Merit, since it reduces the outboard profile drag. However, this tip shape is prone to enter a premature stall, and also increases the risk of a high vibration in the cruising flight [2,6]. The swept tip blade reduces the tip Mach number, allowing the rotor to obtain a higher advance ratio and to operate at tip Mach numbers before the compressibility effect is manifested [7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Assessment of Tip Shape Effect on Rotor Aerodynamic Performance in Hover

Hwang¹,

Kwon²

2015

International Journal of Aeronautical and Space Sciences

View full text Add to dashboard Cite

In the present study, an unstructured mixed mesh flow solver was used to conduct a numerical prediction of the aerodynamic performance of the S-76 rotor in hover. For the present mixed mesh methodology, the near-body flow domain was modeled by using body-fitted prismatic/tetrahedral cells while Cartesian mesh cells were filled in the off-body region. A high-order accurate weighted essentially non-oscillatory (WENO) scheme was employed to better resolve the flow characteristics in the off-body flow region. An overset mesh technique was adopted to transfer the flow variables between the two different mesh regions, and computations were carried out for three different blade configurations including swept-taper, rectangular, and swept-taper-anhedral tip shapes. The results of the simulation were compared against experimental data, and the computations were also made to investigate the effect of the blade tip Mach number. The detailed flow characteristics were also examined, including the tip-vortex trajectory, vortex core size, and first-passing tip vortex position that depended on the tip shape.

show abstract

Rotor Blade Tip Shape Effects on Performance and Control Loads from Full-Scale Wind Tunnel Testing

Cited by 7 publications

References 0 publications

Accurate Predictions of Rotor Hover Performance at Low and High Disc Loadings

Accurate Predictions of Rotor Hover Performance at Low and High Disc Loadings

CFD analysis of hover performance of rotors at full- and model-scale conditions

Assessment of Tip Shape Effect on Rotor Aerodynamic Performance in Hover

Contact Info

Product

Resources

About