Hover Performance Assessment of Several Tip Shapes using OVERFLOW

Narducci, Robert

doi:10.2514/6.2015-1243

Cited by 22 publications

(9 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, the blade anhedral acts similarly as additional negative twist on the blade loading distribution. Similar findings were reported in [16,25,66,67]. The differences in blade loading for the blades with and without anhedral are noticeably lower for the Langley Baseline blade.…”

Section: Blade Planform Shape Effectssupporting

confidence: 86%

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: Blade Planform Shape Effectssupporting

confidence: 86%

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

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The same rotor blade was assessed using the OVERFLOW structured module of HELIOS by Narducci [20,21]. The results obtained with the structured grid method were consistent with the one performed with the unstructured grid method by…”

Section: Model-scale Rotor With Swept-tapered Tip Using the Hpcmp Cresupporting

confidence: 68%

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

“…Therefore, the total number of grid cells and the computational complexity of CFD simulations can become large even for a single four bladed rotor. For example, the reported computational time for two of the results compared with in this article are about 5 days on 240 cores to solve 18 rotations on a mesh of 40 M cells [10] and 5 days on 512 cores to solve 15 rotations on a mesh of 88 M cells [11]. The computational complexity of the problem can be significantly reduced for the axisymmetric hovering case by casting the equations as a steady-state problem in a noninertial reference frame and meshing only a quarter of the domain assuming periodic conditions for the flow in the azimuthal direction, solving 7.5 M cells in 24.8 h on 232 cores [9].…”

Section: Introductionmentioning

confidence: 89%

“…The aerodynamics of S76 rotor blades in and out of ground effect from the hover prediction workshop is investigated with the proposed NL UVLM-VPM. The results are validated with experimental data [55] and compared to various high-fidelity codes from the literature ranging from 3D URANS, 3D detached-eddy simulations (DES) to hybrid 3D URANS-VPM [10,11,[56][57][58][59][60]. Table 1 summarizes the differences in modeling between the methods used in this work and the higher fidelity URANS 3D used for results validation.…”

Section: Introductionmentioning

confidence: 99%

A Hybrid Non-Linear Unsteady Vortex Lattice-Vortex Particle Method for Rotor Blades Aerodynamic Simulations

Proulx-Cabana

Nguyen

Prothin

et al. 2022

Fluids

View full text Add to dashboard Cite

This study presents a hybrid non-linear unsteady vortex lattice method-vortex particle method (NL UVLM-VPM) to investigate the aerodynamics of rotor blades hovering in and out of ground effect. The method is of interest for the fast aerodynamic prediction of helicopter and smaller rotor blades. UVLM models the vorticity along the rotor blades and near field wakes with panels that are then converted into their equivalent vortex particle representations. The standard Vreman subgrid scale model is incorporated in the context of a large eddy simulation for mesh-free VPM to stabilize the wake development via particle strength exchange (PSE). The computation of the pairwise interactions in the VPM are accelerated using the fast-multipole method. Non-linear UVLM is achieved with a low computational cost viscous-inviscid alpha coupling algorithm through a stripwise 2D Reynolds-averaged Navier–Stokes (RANS) or empirical database. The aerodynamics of the scaled S76 rotor blades in and out of ground effect from the hover prediction workshop is investigated with the proposed algorithm. The results are validated with experimental data and various high-fidelity codes.

show abstract

Hover Performance Assessment of Several Tip Shapes using OVERFLOW

Cited by 22 publications

References 10 publications

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

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

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

A Hybrid Non-Linear Unsteady Vortex Lattice-Vortex Particle Method for Rotor Blades Aerodynamic Simulations

Contact Info

Product

Resources

About