Numerical study of the effect of ship attitude on the perform of ship with air injection in bottom cavity

This work aims to numerically study the desaturation process in a coarse-grained sandy deposit by means of air injection. It is well-known that the soil cyclic strength to liquefaction of a saturated, sandy deposit is positively affected by the presence of gas in the void space in either a dissolved or a free form. A numerical study is performed to investigate some of the factors affecting the desaturation advance and controlling the soil desaturation process by air injection. Among these factors are: a) soil-water characteristic curve and intrinsic permeability (hydraulic parameters), b) injection time, and c) standard approach to two injection wells placement. Only the standard mechanisms of biphasic flow are investigated (i.e., incompressible and isothermal biphasic flow in an isotropic homogeneous porous media with capillary effects).

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Numerical Study on Airfoil Diversion Technology Used in Saving Energy by Air Injection on Large Ship

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.3341 ◽

2013 ◽

Vol 353-356 ◽

pp. 3341-3344 ◽

Cited By ~ 1

Author(s):

Ye Qing ◽

Wen Cai Dong ◽

Yong Peng Ou

Keyword(s):

Power Consumption ◽

Numerical Method ◽

Numerical Study ◽

Attack Angle ◽

Air Injection ◽

Plate Surface ◽

Saving Energy ◽

Large Ship ◽

Air Lubrication

The power consumption is too large when the method saving energy by air injection is used on large ship because of the deep draft. The feasibility and some key matters of the implication of airfoil diversion technology on air lubrication ,such as the attack angle, the distance from the airfoil to the plate and the position of the air injection, was investigate by a numerical method. The result shows that the pressure of the air injection entrance is significantly decreased by setting an airfoil at the air injection entrance reasonably, the pressure of the plate surface declines when the distance from the plate to the airfoil is decreasing and the attack angle is increasing, however, the resistance became larger. For the airfoil 2032cjc we investigated in this paper, when d/C=0.3, the attack angle range from 6°~8°,the pressure reduces comparative large and the resistance increases small. The best position for air injection is determined by the position and attack angle of the airfoil.

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Numerical study of a low emission gas turbine like combustor for turbulent ammonia/air premixed swirl flames with a secondary air injection at high pressure

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2017.09.089 ◽

2017 ◽

Vol 42 (44) ◽

pp. 27388-27399 ◽

Cited By ~ 48

Author(s):

Kapuruge Don Kunkuma Amila Somarathne ◽

Sotaro Hatakeyama ◽

Akihiro Hayakawa ◽

Hideaki Kobayashi

Keyword(s):

High Pressure ◽

Gas Turbine ◽

Numerical Study ◽

Air Injection ◽

Secondary Air Injection ◽

Low Emission ◽

Secondary Air

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Experimental and numerical study of ventilation cavitation around a NACA0015 hydrofoil with special emphasis on bubble evolution and air-vapor interactions

Engineering Computations ◽

10.1108/ec-01-2017-0020 ◽

2018 ◽

Vol 35 (3) ◽

pp. 1528-1542 ◽

Cited By ~ 4

Author(s):

An Yu ◽

Xianwu Luo ◽

Dandan Yang ◽

Jiajian Zhou

Keyword(s):

Numerical Investigation ◽

Numerical Study ◽

Simulation Method ◽

Air Injection ◽

Clear Understanding ◽

Vapor Cavity ◽

Content Type ◽

Suppression Effect ◽

Shedding Frequency ◽

Bubble Evolution

Purpose This paper aims to gain a clear understanding of the ventilated cavity evolution around an NACA0015 hydrofoil by using both experimental and numerical investigation. Design/methodology/approach The bubble evolution around an NACA0015 hydrofoil with or without air injection was observed in a water tunnel, and the simulation was conducted using a modified turbulence model and homogeneous cavitation model. Findings The present simulation method can successfully predict the bubble evolutions around the NACA0015 hydrofoil with or without air injection. Air injection can alleviate the nature cavitation oscillation, and the suppression effect on nature cavitation depends on the air-entrant coefficient. It is confirmed that the air and vapor cavity have the same shedding frequency. It is seen that the air sheet closely attaches to the hydrofoil surface and is surrounded by the vapor sheet. Thus, the injected air promotes vapor growth and results in an increase in the cavity shedding frequency. Further, with a large air-entrant coefficient, the pressure fluctuation is suppressed completely. Originality/value The new simulation method is adopted to explore the mechanism of ventilated cavitation. The bubble evolutions with and without air injection have been comprehensively studied by experimental and numerical investigation. The effects of air injection on natural cavity oscillations and pressure fluctuations have been revealed in the present study.

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The Numerical Study of a New Air-Cooled Turbine Blade With Depression Feature at Leading Edge

Volume 6: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2008-50238 ◽

2008 ◽

Author(s):

Songtao Wang ◽

Kai Wang ◽

Xiaoqing Qiang ◽

Zhongqi Wang

Keyword(s):

Flow Field ◽

Energy Loss ◽

Turbine Blade ◽

Pressure Field ◽

Numerical Study ◽

Leading Edge ◽

Aerodynamic Characteristics ◽

Air Injection ◽

Blade Profile ◽

Cooling Air

A new air-cooled turbine blade with depression feature at leading edge was presented in this paper. The flow field of this blade at the transonic condition was simulated in detail. The change of vortex position induced by the leading edge cooling air injection along the blade profile was observed. The aerodynamic characteristics of the new blade such as film effectiveness, energy loss, pressure field etc. were compared with the traditional air-cooled turbine blade. The result shows that this new blade locks the vortex induced by the leading edge cooling air injection in its depression part. The mixing of cooling air and mainstream becomes weak. Thus, the number of the leading edge cooling air injection holes can be reduced. Correspondingly, the amount of injection can also be reduced.

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