Numerical Study of Helicopter Rotors in a Ship Airwake

Crozon, C.; Steijl, R.; Barakos, George N.

doi:10.2514/1.c032535

Cited by 59 publications

(24 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Not surprisingly, maneuvering for safe landing onboard a ship is a complex problem since the rotor flow field, wake, and unsteady aerodynamic loads are altered by the presence of the ship deck, and ship wake. The pilot workload during helicopter shipboard landing and take-off is then significantly increased [1][2][3]. Moreover, during flight operations, especially for take-off and landing, numerous factors expose flight and ground crew to substantial risks [4].…”

Section: Introductionmentioning

confidence: 99%

“…In other words, so far in published works, the rotorcraft experienced disturbances due to a pre-calculated CFD ship air-wake, but the ship air-wake CFD solutions were unaffected by the downwash of the rotor. The effect of the rotor downwash was then accounted for in the aerodynamics of the rotorcraft-ship system by including a ship wake from CFD tools such as the Rot3DC [22], PUMA2 [23], OVERFLOW [24], CRUNCH [25], and HMB [1], and coupling it into flight dynamic simulations. However, the unsteady mutual interaction between the ship air-wake and the rotor wake is not taken into account.…”

Section: Introductionmentioning

confidence: 99%

“…Also, the importance of coupling effects on the wake when the rotor is operating close to the ship and the invalidity of superposition methods were demonstrated in Ref. More recently, full-CFD approaches with overset grid systems [1,26] were used to investigate the rotor flow field above the ship deck, and overcome the limitations of superposition method. However, the concentrated vorticity predicted by CFD is affected by several factors, such as excessive numerical dissipation, and lack of highdensity grids, needed to capture the rotor wake.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations

Tan

Zhou

Sun

et al. 2019

Aerospace Science and Technology

View full text Add to dashboard Cite

Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations.Abstract: Complex rotorcraft-to-rotorcraft interference problems occur during shipboard operations, and have a negative impact on safety. A vortex-based approach is used here to investigate the flow field and unsteady airloads of a tiltrotor affected by the wake of an upwind tandem rotor. In this work, the blade aerodynamics is modelled using a panel method, and the unsteady behavior of rotor wakes is modelled using a vortex particle method. The effects of the ship and sea-surfaces are accounted for via a viscous boundary model. The method is applied to a 1/48 th scaled model of a CH-46 operating on a model-scale Landing Helicopter Assault ship. The predicted vertical velocities at the location of the downstream V-22 are compared with Computational Fluid Dynamics and experiments carried out at NASA Ames Research Center. The results show that the predicted vertical velocities compare reasonably well with experiments and Computational Fluid Dynamics. A V-22 tilt-rotor placed in the wake of the CH-46 is also simulated, and rolling moments of the V-22 are calculated to show the effect of the upstream CH-46 wake. Keywords: rotorcraft-to-rotorcraft interference; flow field; shipboard operation; vortex particle method; viscous boundary model Nomenclature b, f = edge lengths of a rectangular panel, m b v = the V-22 wing span, m p C = pressure coefficient, dimensionless C P = rotor power coefficient, dimensionless 1 Lecturer, JianfengTan@njtech.edu.cn.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations

Tan

Zhou

Sun

et al. 2019

Aerospace Science and Technology

View full text Add to dashboard Cite

show abstract

“…Experimental studies [6][7][8][9] include wind-tunnel measurements of the ship airwake, rotor/ship aerodynamic interaction and rotor/terrain interaction. Numerical studies [10][11][12] include characterization of ship wakes with different numerical models, interaction of rotor/ship and rotor/terrain interaction, integration of the results into simulation environment and simultaneous CFD simulations of ship/aircraft and other efforts 13,14 to couple CFD and flight dynamics to capture coupling interactions as proposed in this study. However these studies were very far from real-time.…”

Section: Introductionmentioning

confidence: 99%

Towards real-time pilot-in-the-loop CFD simulations of helicopter/ship dynamic interface

Oruc

Horn

Shipman

et al. 2017

Int. J. Model. Simul. Sci. Comput.

View full text Add to dashboard Cite

This study presents the development of computationally efficient coupling of NavierStokes Computational Fluid Dynamics (CFD) with a helicopter flight dynamics model with the ultimate goal of real-time simulation of airwake effects in the helicopter/ship Dynamic Interface (DI). The flight dynamics model is free to move within a computational domain, where the main rotor forces are converted to source terms in the momentum equations of the CFD solution using an actuator disk model. Simultaneously, the CFD solver calculates induced velocities that are fed back to the simulation and affect the aerodynamic loads in the flight dynamics. The CFD solver models the inflow, ground effect and interactional aerodynamics in the flight dynamics simulation, and these calculations can be coupled with the solution of the external flow (e.g., ship airwake effects). The simulation framework for fully-coupled pilot-in-the-loop (PIL) flight dynamics/CFD is demonstrated for a simplified shedding wake. Initial tests were performed with 0.38 million structured grid cells running on 352 processors and showed near-real-time performance. Improvements to the coupling interface are described that allow the simulation run at near-real-time execution speeds on currently available computing platforms. Improvements in computing hardware are expected to allow real-time simulations.

show abstract

“…Oruc, Horn, Polsky, Shipman, and Erwin (2015) used the efficient and simple momentum source approach (Rajagopalan & Mathur, 1989), which considers the time-averaged effect of the rotor across the disk to conduct the numerical calculation of rotor/ship flowfield for the development of a virtual dynamic interface simulation. In the work of Crozon, Steijl, and Barakos (2014), the two aforementioned methods were employed over the Canadian Patrol Frigate to demonstrate the importance of coupling effect on the wake and rotor inflow. Although the momentum source approach has been used in numerical studies of ship/rotor flowfield, whether this method can accurately predict various complex interactions that occur during the helicopter shipboard launch, and the specific difference in velocity distribution between two methods, is not clear.…”

Section: Introductionmentioning

confidence: 99%

An investigation of coupling ship/rotor flowfield using steady and unsteady rotor methods

Shi

Zong

et al. 2017

Engineering Applications of Computational Fluid Mechanics

View full text Add to dashboard Cite

A coupling numerical methodology has been developed using the Navier-Stokes solver for ship/rotor flowfield simulation during the helicopter shipboard launch. The steady rotor model (SRM) based on the momentum source approach and unsteady rotor model (URM) based on the moving overset mesh method are respectively employed to account for rotor operations. Studies of coupling ship/rotor flowfield on two typical ships highlight complex interactions over the flight deck. It is shown that the rotor-shipboard vortex interaction and recirculation zone are more serious for small-sized-deck destroyers, while on the straight-through-deck ship the helicopter operations are sensitive to asymmetric distribution of lateral velocity caused by the island. Qualitative and quantitative comparisons in terms of vorticity and velocity between SRM and URM solvers have been conducted. The results demonstrate that both methods can capture complex interactions well. The velocity difference is within 1 m/s in most flowfield areas, except the rotor-wake dominant region. With the consideration of computational efficiency, the momentum source approach could be used to effectively conduct the study of helicopter shipboard operations. ARTICLE HISTORY

show abstract

Numerical Study of Helicopter Rotors in a Ship Airwake

Cited by 59 publications

References 24 publications

Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations

Numerical investigation of the aerodynamic interaction between a tiltrotor and a tandem rotor during shipboard operations

Towards real-time pilot-in-the-loop CFD simulations of helicopter/ship dynamic interface

An investigation of coupling ship/rotor flowfield using steady and unsteady rotor methods

Contact Info

Product

Resources

About