Concurrent Aerodynamic Optimization of Rotor Blades Using a Nash Game Method

Leon, Enric Roca; Pape, Arnaud Le; Costes, M.; Désidéri, Jean‐Antoine; Alfano, David

doi:10.4050/jahs.61.022009

Cited by 19 publications

(17 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The steady state method uses assumptions such as periodicity that significantly improve the simulation time, but still uses the RANS equations to accurately capture the tip vortex formation and roll-up effects. For this reason, this method has been utilised in many optimisation studies for rotors in hover [28][29][30][31]. Another important aspect to highlight is the fact that while CFD methods and more accurate hover performance predictions are obtained, the accuracy of flight test data and wind tunnel data is not sufficient to validate high-fidelity CFD methods.…”

Section: Introductionmentioning

confidence: 99%

Validation of the Steady-State Hover Formulation for Accurate Performance Predictions

et al. 2019

View full text Add to dashboard Cite

This paper shows accurate predictions for hover performance regardless of planform geometry, blade tip Mach number or disk loading. To prove this statement, sensitivity analyses were performed along with performance predictions for four rotor designs. Planform effects were also studied, such as blade anhedral, showing the strong sensitivity of the rotor blade performance due to geometric features. The steady state solution methodology with imposed Froude boundary conditions is shown to give accurate results for relatively coarse grid sizes. This approach leads to reduced computational costs compared to time-dependent simulations. It is also recognised that given the current accuracy of the available experimental data, the use of more advanced CFD methods may not be fully justified. To advance the accuracy of modern CFD methods a more comprehensive experimental dataset is required. Nomenclature AR = aspect ratio, R/c r e f a = speed of sound, m/s C p = pressure coefficient, (p − p ∞ )/(1/2ρ(Ωr/R) 2 ) C f = skin friction coefficient, τ w /(1/2ρ(Ωr/R) 2 ) C Q = torque coefficient, Q/( ρ(ΩR) 2 πR 3 ) C T = thrust coefficient, T/( ρ(ΩR) 2 πR 2 ) c = rotor chord, m E = endurance, s FoM = figure of merit, C 3/2 T /( √ 2C Q ) k = turbulent kinetic energy, m 2 /s 2 M = Mach number, V ∞ /a ∞ M tip = blade tip Mach number, ΩR/a ∞ * PhD Student, CFD Laboratory, School of Engineering.

show abstract

Section: Introductionmentioning

confidence: 99%

Validation of the Steady-State Hover Formulation for Accurate Performance Predictions

et al. 2019

View full text Add to dashboard Cite

show abstract

“…studies (7)(8)(9)26) , when the objective is to maximise the FoM. This can be avoided by reformulating the objective as a power minimisation problem at constant thrust.…”

Section: Performance Metricsmentioning

confidence: 99%

“…The experiments by Yeager et al (6) , matched the thrust-weighted solidity between a rectangular and BERP planform. Various optimisation studies have also kept this parameter constant (7)(8)(9) , which leads to favourable treatment of planforms with lower blade area across the blade tip, as seen by Perry (5) for the BERP and tapered planforms. The analyses of Perry (5) need to be supported by findings using highfidelity Navier-Stokes methods, to establish the correct usage of solidity when comparing different rotor designs.…”

Section: Introductionmentioning

confidence: 99%

Assessment of current rotor design comparison practices based on high-fidelity CFD methods

2020

View full text Add to dashboard Cite

This paper provides an assessment of current rotor design comparison practices. First, the employed CFD method is validated for a number of rotor designs and is shown to achieve accurate performance predictions in hover and high-speed forward flight. Based on CFD results, a detailed investigation is performed in terms of comparing different rotor designs. The CFD analysis highlighted the need of high fidelity methods due to the subtle aerodynamics involved in advanced planforms. Nevertheless, the paper suggests that the correct basis for comparison in terms of performance metrics must be used to inform decisions about the suitability of the rotor blades designs for specific applications. In particular, when comparing blades of advanced planforms, direct torque and thrust comparisons are better than the commonly used lift to drag ratio and figure of merit.

show abstract

“…Recently, the use of gradient-based algorithms formulated by the discrete steady adjoint of the RANS equations has allowed high-fidelity models in hover optimizations, since the cost of the gradient evaluation becomes practically independent of the number of design parameters [4] [5]. The optimization problem is more complex in forward flight.…”

mentioning

confidence: 99%

Multifidelity Aerodynamic Optimization of a Helicopter Rotor Blade

Bailly

2019

AIAA Journal

View full text Add to dashboard Cite

A multi-fidelity optimization technique is applied to the design of a helicopter rotor blade to improve its performance in forward flight. This optimization technique is based on surrogate model that replace the high-fidelity CFD/CSD simulations necessary to capture the three-dimensional unsteady effects generated in the flow field of a complex blade geometry. The single low-fidelity model based on Kriging methodology and generated by lifting-line simulations, leads to a power benefit of 2.5%, which is not reproducible by an a posteriori high-fidelity CSD/CFD computation. The optimization procedure using Co-Kriging surrogate models based on two levels of fidelity (lifting line and CSD/CFD simulations) leads to a realistic blade planform, for which the power benefit is estimated at 2.2%. This optimized solution, obtained after a factor 6 reduction in CPU time, shows the advantages of using a Co-Kriging surrogate model (rather than a single-fidelity Kriging model) for aerodynamic optimizations.

show abstract

Concurrent Aerodynamic Optimization of Rotor Blades Using a Nash Game Method

Cited by 19 publications

References 2 publications

Validation of the Steady-State Hover Formulation for Accurate Performance Predictions

Validation of the Steady-State Hover Formulation for Accurate Performance Predictions

Assessment of current rotor design comparison practices based on high-fidelity CFD methods

Multifidelity Aerodynamic Optimization of a Helicopter Rotor Blade

Contact Info

Product

Resources

About