CFD Study of Drag Reduction in Axisymmetric Underwater Vehicles using Air Jets

Shereena, S. G.; Vengadesan, S.; Idichandy, V. G.; Bhattacharyya, S. K.

doi:10.1080/19942060.2013.11015464

Cited by 26 publications

(23 citation statements)

References 22 publications

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“…The turbulent viscosity is the most important factor. Previous research had been proposed by Crowe, Elger, and Roberson (2005), Shereena, Vengadesan, Idichandy, and Bhattacharyya (2005). The turbulent viscosity generated not only the skin friction drag but also the pressure drag.…”

Section: Introductionmentioning

confidence: 99%

Effects of residual riblets of impeller's hub surface on aerodynamic performance of centrifugal compressors

Dong

Li-xin

2015

Engineering Applications of Computational Fluid Mechanics

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In this article, the effects of residual riblets of impeller's hub surface on the aerodynamic performance of a compressor are studied in detail. Several accurate geometrical models of impellers after their hub surface are machined, with various tool passes are built. The number of tool passes for the hub surface finish of a single passage of the impeller is denoted by N. Meanwhile, a dimensionless parameter B max is introduced to characterize the size of the ribs of the arbitrary impeller, which is the percentage ratio rate of the maximum cusp height of the hub surface to the exit blade width. The geometrical models are numerically studied by solving the Reynolds averaged Navier-Stokes equations using the SST turbulent model. The predictions show that a group of secondary cross-stream vortices are generated by the interaction of streamwise vortices above the hub surface with riblets' tips. For the impeller researched in this article, with the decline of B max , the average viscous shear stress on the hub surface decreases gradually at first and then starts increasing and leveling off; accordingly, the polytropic efficiency of the compressor, on the contrary, increases gradually and then starts leveling off later. When B max comes to 0.58, the average viscous shear stress of the fluids on the hub surface reaches its minimum, and it is found that the polytropic efficiency of the compressor reaches a peak and stable value. The simulation results are validated against experimental data at the design Mu, and the maximum discrepancies are less than 3.8%.

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Section: Introductionmentioning

confidence: 99%

Effects of residual riblets of impeller's hub surface on aerodynamic performance of centrifugal compressors

Dong

Li-xin

2015

Engineering Applications of Computational Fluid Mechanics

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“…It is important to use an accurate and effective numerical solver when working on hull form hydrodynamic optimization based on computational fluid dynamics (CFD; Kim & Yang, 2010;Shereena, Vengadesan, Idichandy, & Bhattacharyya, 2013). As the ship total resistance is defined as the objective function of the hydrodynamic optimization cycle in this study, the respective hydrodynamic computation is resolved by the frictional resistance evaluated by the International Towing Tank Conference (ITTC) 1957 model-ship correlation formula and the wave-making resistance estimated by the Rankine source panel method with nonlinear free-surface boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

A hydrodynamic optimization design methodology for a ship bulbous bow under multiple operating conditions

Chang

2016

Engineering Applications of Computational Fluid Mechanics

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The main objective of this article is to describe an innovative methodology for the hydrodynamic optimization of a ship bulbous bow which considers multiple operating conditions. The proposed method is more practical and effective than the traditional optimization process, which is only based on contractually specified design condition. Parametric form approaches are adopted by employing an F-spline curve in order to generate variants of the hull bulbous bow forms using form design parameters modified, resulting in an optimization system based on improved genetic algorithms. The Rankine source panel method is used for the hydrodynamic evaluation, wherein non-linear free surface conditions and the trim and sinkage of the ship are taken into consideration. The validity and effectiveness of the proposed methodology for a large container ship is investigated by comparing the computational results with experimental data, which demonstrates that the proposed methodology can engage well in the automation process and improve hydrodynamic performance during actual ship design practices. ARTICLE HISTORY

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“…Pang et al (2014) investigated microbubble drag reduction using the Euler-Lagrange two-way coupling method in order to understand the drag reduction mechanism from such bubbles. Shereena et al (2014) conducted a numerical simulation using k- SST to calculate the drag reduction produced by an air jets on axisymmetric-underwater vehicles. Air lubrication requires an injection to disperse air into the water; this requires energy due to the relatively high pressure in the water, particularly at certain depths in a ship's bottom hull.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study on Influence of Hydrofoil Clearance Towards Total Drag Reduction on Winged Air Induction Pipe for Air Lubrication

Yanuar¹,

Putra²,

Akbar³

et al. 2020

IJTech

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A new device for air lubrication called the Winged Air Induction Pipe (WAIP) is studied in the present work. The device, which consists of an angled hydrofoil, uses the low-pressure region produced above the hydrofoil as a ship moves forward. The low pressure drives the atmospheric air into the water at certain velocities when the pressure is negative compared to atmospheric pressure. A computational fluid dynamics approach is presented in the study of the effect of the hydrofoil clearance of the Winged Air Induction Pipe on the drag reduction experienced by the plate to which the WAIP is attached. The well-known 'volume of fluid' model and k- SST (shear stress transport) turbulence closure model were used in the 2D numerical simulation in ANSYS Fluent. The numerical simulation was conducted with different hydrofoil clearance and angle of attack configurations, and the effects of these parameters on total drag force and drag reduction are reported. The reduction of drag force is found to increase by about 10% compared to the bare plate configuration.

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CFD Study of Drag Reduction in Axisymmetric Underwater Vehicles using Air Jets

Cited by 26 publications

References 22 publications

Effects of residual riblets of impeller's hub surface on aerodynamic performance of centrifugal compressors

Effects of residual riblets of impeller's hub surface on aerodynamic performance of centrifugal compressors

A hydrodynamic optimization design methodology for a ship bulbous bow under multiple operating conditions

Numerical Study on Influence of Hydrofoil Clearance Towards Total Drag Reduction on Winged Air Induction Pipe for Air Lubrication

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