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By modelling the unsteady heat transfer in liquid gas tanks, the temperature distribution in the tank as well as the heat flux reaching the liquid gas can be predicted. Knowledge of the temperature distribution and heat flux can be used to predict evaporation losses from the tank. By minimizing the evaporation losses, the thermal design of a gas tank can be optimized. This paper presents a finite difference simulation of the unsteady three‐dimensional heat transfer in gas tanks and an optimized configuration. The numerical procedure accounts for radiation from the sun as well as radiative and convective heat transfer with the environment. A non‐uniform grid is used because the tank consists of several different materials of varying dimensions and properties. Geometrical effects such as variations in the thickness of the insulation material and the diameter and height of the tanks are also studied in an attempt to optimize the design configuration.

PAINTS as methods of passive corrosion protection must be considered essential for steel and metal structures, and are as old as the need to preserve their value. Moreover, the attempt has long been made, not only to cover the surfaces of steels with organic paints, but also to protect them actively and thereby to exclude the danger of under‐rusting as a result of crack and pore formation or absorption of water in the organic paint films. Such active corrosion protection is already about 200 years old. But the development, the manufacturing technique, and not least the price, often make it impossible to provide surfaces with a coating by hot‐dip or spray galvanizing.

IN the testing of rocket engines and engine components, such as thrust chambers and gas generators, the rocket engineer is regularly faced with the job of transferring cryogenic liquid propellants, using pressure feed from a storage tank, through a flow system and into the combustion device to be tested. At Rocketdyne, liquid oxygen, LOX, is quite commonly used as a propellant, and in the testing of engine components inert pressurants are usually used, for example, helium or nitrogen, although because of the cost and logistics, nitrogen is preferred. When gaseous nitrogen is used as the pressurant, we have repeatedly run into testing conditions which have resulted in condensation of nitrogen and subsequent mixing in the tanked liquid oxygen. This dilution of the liquid oxygen effects a loss of performance and imposes mechanical difficulty in maintaining a regulated propellant tank pressure.

DESPITE the quite extensive literature on foam, the mechanism of its formation and decay does not appear to be widely appreciated. Most fundamental research has been orientated towards maximum foam in aqueous solutions, whereas the desire in aircraft engines is for minimum foam in oil ‘solutions’. Further, the numerical results obtained experimentally depend on the details of experimental procedure, which makes correlation of existing data very uncertain.

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The purpose of this paper is to analyze the liquid sloshing behaviors in two-dimensional tanks with various porous baffles under the external excitation.

Adopting the finite element method (FEM) and control variable method to study the impacts of the height, length, number, location, shape, porous-effect parameter of the porous baffle, the external load frequency and the shape of the tank on the liquid sloshing response.

The amplitude of the free surface can be reduced effectively when the baffle opening is appropriate. The anti-sway ability of the system increases in pace with the baffle’s height growing. Under the same conditions, the shapes of the baffles have an important effect on improving the anti-sway ability of the system.

As there exist the differences of the velocity potential between each side of the porous baffle, which means that there are two different velocity potentials at a point on the porous baffle, the conventional finite element modeling technologies are not suitable to be applied here. To deal with this problem, the points on the porous baffle are regarded as two nodes with the same coordinate to model and calculate.

Determining the variation law of the oxygen concentration in the ullage space of the fuel tank is the key to the design of the inert system. Among various factors affecting the oxygen concentration in the ullage space of the fuel tank, the temperature difference between day and night shows particular importance while relevant analysis and calculation are scarce.

This study establishes a theoretical simulation model of the central wing fuel tank of an aircraft according to the relevant provisions of day-night temperature variation in FAR25 airworthiness regulations, verifies the model with the existing experimental data and discusses the corresponding relationship between the oxygen concentration in the ullage space of the fuel tank and the day-night temperature difference. The influence of day and night temperature difference, fuel type, fuel load rate, initial oxygen concentration, dissolved oxygen evolution and other factors on the oxygen concentration in the ullage space of the fuel tank were analyzed, and the limit of initial oxygen concentration of the fuel tank before the shutdown at night meeting the requirements of the airworthiness provisions was proposed.

The results show that the temperature difference between day and night, fuel load rate, initial oxygen concentration and other factors have different effects on the oxygen concentration in the ullage space of fuel tank. The initial oxygen concentration limit before shutdown shall be 2% below the 12% oxygen concentration stipulated by FAA.

The research results in this paper will be of good reference value to the design of the inert system and the calculation of the flammability exposure evaluation time. This paper aims to be good reference of the design of the inert system and the calculation of the flammability exposure evaluation time.

The research results of this paper can provide practical guidance for the current civil airworthiness certification work.

The paper aims to present a numerical modeling procedure for the analysis of liquid sloshing in a flexible tank subjected to an external excitation, with taking into account the effects of fluid–structure interaction (FSI).

A numerical model based on coupling a two-phase flow solver and an elastic solid solver is developed in OpenFOAM code. The Arbitrary Lagrangian–Eulerian formulation is adopted for the two-phase Navier–Stokes equations in a moving domain. The volume of fluid (VOF) method is applied for the air–liquid interface tracking. The finite volume method is used for the spatial discretization of both the fluid and the structure dynamics equations. The FSI coupling problem is solved by an explicit coupling scheme. The model is validated for linear and nonlinear sloshing cases. Then, it is used to analyze the effects of the liquid sloshing on the dynamic response of the tank and the effects of the tank flexibility on the liquid sloshing.

The obtained results show that the flexibility of the tank walls amplifies the amplitude of the sloshing and increases the fluctuation period of the air–liquid interface. Furthermore, it is found that the bending moment acting on the tank walls may be underestimated when rigid walls assumption is adopted as usually done in sloshing tank modeling. Also, tank walls flexibility causes a phase shift in the free surface dynamic response.

A review of previous studies on liquid sloshing in flexible tanks revealed that FSI effects have not been clearly and comprehensively analyzed for large-amplitude liquid sloshing. Many physical and numerical aspects of this problem still require clarifications and enhancements. The added value of the present work and its originality lie in the investigation of large-amplitude liquid sloshing in flexible tanks by using a staggered coupling approach. This approach is carried out by an original combination of a linear solid solver with a two phase fluid solver in OpenFOAM code. In addition, FSI effects on some response quantities, identified and analyzed herein, have not been found in the previous works.