The hydrodynamic interaction of turbulent flow with tandem hydrofoils in presence of a free surface

Kumari, Nutan; Chakraborty, Arnab

doi:10.1109/oceanschennai45887.2022.9775488

Cited by 3 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Einstein notation, the unsteady RANS equations for three-dimensional, unsteady turbulent flow of an incompressible fluid can be written as 6,34,35,41 :…”

Section: Mathematical Formulation For the Boundary Conditionsmentioning

confidence: 99%

The hydrodynamic analysis of multiple hydrofoils translating in tandem in presence of a free surface

Kumari

Chakraborty

Jangam

2022

Proceedings of the Institution of Mechanical Engineers, Part M:

Self Cite

View full text Add to dashboard Cite

Hydrofoils find its presence in various engineering applications including high speed marine crafts, blades of hydro-kinetic turbines etc. So, depending on the type of marine application, the foils are arranged in different complex arrangements (i.e. in line, or in tandem) that can alter flow dynamics of the working fluid flowing around them. In order to design efficient marine propulsion systems, it is important to study the effect of different arrangements of hydrofoil systems on its hydrodynamic characteristics (lift, drag, pressure coefficient, velocity contour, etc). In this study, the numerical simulation of fluid flow over a tandem hydrofoils is carried out in presence of a free surface. The present study is limited for a constant Reynolds number of 166,784.8, and at a Froude number of 0.57. The unsteady RANS equations are solved using the volume of fluid (VOF) method embedded in commercial software STAR-CCM+ incorporating [Formula: see text] turbulence model. The first part of the study focuses on varying spacing ratios ( l/ c) that range from 0.1 to 4. In the second part of the study, the angle of attack of the downstream hydrofoil was varied over zero degrees to stall keeping the upstream hydrofoil at a zero degree angle of attack. For both studies, pressure and velocity distributions, lift as well as drag coefficients were evaluated. It is concluded that the presence of a free surface in a close proximity to the foils, different spacing between the hydrofoils, and varying angle of attacks of the downstream hydrofoil have significant effects on the overall performance.

show abstract

“…In Einstein notation, the unsteady RANS equations for three-dimensional, unsteady turbulent flow of an incompressible fluid can be written as 6,34,35,41 :…”

Section: Mathematical Formulation For the Boundary Conditionsmentioning

confidence: 99%

The hydrodynamic analysis of multiple hydrofoils translating in tandem in presence of a free surface

Kumari

Chakraborty

Jangam

2022

Proceedings of the Institution of Mechanical Engineers, Part M:

Self Cite

View full text Add to dashboard Cite

show abstract

A numerical simulation of turbulent flow characteristics through periodic grooves of varying curvatures

Mukherjee,

Chakraborty,

Srivastava

et al. 2024

Sādhanā

View full text Add to dashboard Cite

A Simplified Mathematical Model of Pumped Hydrofoils

Rozhdestvensky

2023

JMSE

View full text Add to dashboard Cite

This paper presents a simplified mathematical model of a pumped hydrofoil (PH)—a surfboard elevated above water surface and connected to a tandem of hydrofoils by a strut. The PH is operated by a rider who stands on the surfboard and produces swinging up-and-down motions resulting in forward propulsion of the device. In the present paper, the description of the vertical motion of the PH is reduced to a linear oscillator excited by an oscillating mass coupled with the requirement that the weight is supported by dynamic lift of the foil(s). The inertial and damping influence of the hydrofoil(s) is accounted for by expanding unsteady lift force on the foil(s) in terms of kinematic parameters. The restoring term of the oscillator is associated with the phenomenon of automatic stabilization of shallowly submerged hydrofoils. The latter effect manifests itself in that when a hydrofoil approaches free surface, its lift decreases, and when it moves away from free surface, its lift increases. The analytical solution of the pumping foil mass-spring type forced oscillations equation allows one to calculate the flapping motion of the foil(s) and, thereafter, the period-averaged thrust generated by the PH. The resulting speed has been estimated on an assumption that the device enters its cruising mode when the thrust becomes equal to the drag, the latter comprising viscous, wave, and induced drag components. The model under discussion allows one to relate the main parameters of the system to its performance and, hopefully, provides further insight into the pumped hydrofoil phenomenon, its design methodology, and operation strategy. The review part of the paper focuses on two aspects of the problem: hydrodynamic behavior of the hydrofoil(s) in proximity to free water surface and their propulsion due to oscillations.

show abstract

The hydrodynamic interaction of turbulent flow with tandem hydrofoils in presence of a free surface

Cited by 3 publications

References 13 publications

The hydrodynamic analysis of multiple hydrofoils translating in tandem in presence of a free surface

The hydrodynamic analysis of multiple hydrofoils translating in tandem in presence of a free surface

A numerical simulation of turbulent flow characteristics through periodic grooves of varying curvatures

A Simplified Mathematical Model of Pumped Hydrofoils

Contact Info

Product

Resources

About