Hydrodynamic simulation of an oscillating hydrofoil near free surface in critical unsteady parameter

Esmaeilifar, Esmaeil; Djavareshkian, Mohammad Hassan; Feshalami, Behzad Forouzi; Esmaeili, Ali

doi:10.1016/j.oceaneng.2017.06.037

Cited by 26 publications

(11 citation statements)

References 36 publications

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“…Moreover, hydrofoil 1 had led to the turbulence of flow behind hydrofoil 2; hence, the minimum pressure coefficient on the surface has been reduced. As a result, supercavitation on hydrofoil 2's surface is more evolved [15][16][17][18][19].…”

Section: Discussionmentioning

confidence: 99%

Numerical Study on the Tandem Submerged Hydrofoils Using RANS Solver

ArianMaram

Ghafari

Ghassemi

et al. 2021

Mathematical Problems in Engineering

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This paper is presented on the tandem two-dimensional hydrofoils with profiles NACA4412 in single-phase and two-phase flow domains for different submergence depths and different distances in a various angle of attack (AoA). Also, supercavitation is studied at σ = 0.34 by the Zwart cavitation model. Reynolds-averaged Navier–Stokes (RANS) with the shear stress transport (SST) K-ω is employed as a turbulence model in transient analysis of Ansys FLUENT software. The numerical results show that, by increasing depth, the drag coefficient increases for both hydrofoils 1 and 2 as well as the lift coefficient. The drag coefficient of hydrofoil 2 is bigger than hydrofoil 1 for all depths; moreover, it was found that the flow pressure behind the hydrofoil 1 had affected the upper and the lower surface of the hydrofoil 2 at each distance or AoA. These effects are observed in the hydrofoil 2 lift coefficient as well as the flow separation. However, the maximum lift-to-drag ratio is observed at AoA = 8 ° and 3.5c distance. Also, single-phase results reveal that the value of pressure and the hydrodynamic coefficient are very different from the two-phase flow results, due to the elimination of the free surface. So, a two-phase flow domain is recommended for increasing the accuracy of results. In addition, the investigation of supercavitation shows a growth in cavity occurrence on the surface by raising AoA.

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Section: Discussionmentioning

confidence: 99%

Numerical Study on the Tandem Submerged Hydrofoils Using RANS Solver

ArianMaram

Ghafari

Ghassemi

et al. 2021

Mathematical Problems in Engineering

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“…A C-type mesh is used to model the flow around the airfoil due to better performance than H and O-types for simulation of pitching motion (Esmaeilifar et al 2017). In other words, the quality of other mesh types is lower than that of C-type (Ferrari 2012).…”

Section: Mesh and Boundary Conditionsmentioning

confidence: 99%

Numerical Simulation of a Pitching Airfoil Under Dynamic Stall of Low Reynolds Number Flow

Honarmand

Djavareshkian

Feshalami

et al. 2019

J.Aerosp. Technol. Manag.

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In this research, viscous, unsteady and turbulent fluid flow is simulated numerically around a pitching NACA0012 airfoil in the dynamic stall area. The Navier-Stokes equations are discretized based on the finite volume method and are solved by the PIMPLE algorithm in the open source software, namely OpenFOAM. The SST k - ω model is used as the turbulence model for Low Reynolds Number flows in the order of 105. A homogenous dynamic mesh is used to reduce cell skewness of mesh to prevent non-physical oscillations in aerodynamic forces unlike previous studies. In this paper, the effects of Reynolds number, reduced frequency, oscillation amplitude and airfoil thickness on aerodynamic force coefficients and dynamic stall delay are investigated. These parameters have a significant impact on the maximum lift, drag, the ratio of aerodynamic forces and the location of dynamic stall. The most important parameters that affect the maximum lift to drag coefficient ratio and cause dynamic stall delaying are airfoil thickness and reduced frequency, respectively.

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“…Results showed that the tip vortex of the flap and wing is diminished in a low ground clearance. In another research study, authors studied the physics of fluid around an oscillating hydrofoil near water free surface [26].…”

Section: Introductionmentioning

confidence: 99%

Experimental study of low Reynolds number effects on aerodynamics of smooth and sinusoidal leading-edge wings in the vicinity of the ground

Mehraban

Djavareshkian

2021

JMES

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Present study experimentally investigates the effects of ground clearance and Reynolds number on aerodynamic coefficients of smooth and sinusoidal leading-edge wings. Wind tunnel tests are conducted over a wide range of angles of attack from zero to 36 degrees, low Reynolds numbers of 30,000, 45,000 and 60,000, and also ground clearances of 0.5, 1 and ∞. Results showed that reduction of ground clearance and increment of Reynolds number cause the lift coefficient and the lift to drag ratio of both wings to be enhanced. Furthermore, the effects of Reynolds number and ground clearance on the smooth leading-edge wing are more than the sinusoidal leading-edge one. In addition, the sinusoidal leading-edge wing shows an excellent performance in the poststall region due to producing a higher lift and also by delaying the stall angle compared to the smooth leading-edge wing.

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Hydrodynamic simulation of an oscillating hydrofoil near free surface in critical unsteady parameter

Cited by 26 publications

References 36 publications

Numerical Study on the Tandem Submerged Hydrofoils Using RANS Solver

Numerical Study on the Tandem Submerged Hydrofoils Using RANS Solver

Numerical Simulation of a Pitching Airfoil Under Dynamic Stall of Low Reynolds Number Flow

Experimental study of low Reynolds number effects on aerodynamics of smooth and sinusoidal leading-edge wings in the vicinity of the ground

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