Conjugate heat transfer in the mode of thermal gravitational-capillary convection in the model of a fuel tank, after a sudden heating of the sidewall

The evolution of unsteady gravitational-capillary convection in a layer of ethyl alcohol with a free surface after sudden electric heating of one of the vertical walls of a rectangular cavity was investigated numerically. The effect of the incoming flow of hot liquid on the time evolution of the temperature field on the opposite thin metal wall of the cavity was investigated. The calculations were carried out by the finite element method in the conjugate two-dimensional formulation with the Prandtl number Pr = 16, and the range of Grashof numbers determined by the heat flux density, 33·103 ≤ Gr ≤ 28·106. It is shown that the maximum local temperature gradients occur on the wall near the liquid-gas interface.

Empirical Coastal Atmospheric Corrosion of Masonry Metal Wall Ties

Not counting domestic dwellings, it has been estimated that in Australia alone, some tens of thousands of masonry buildings and structures have exceeded their design life, with many of these being at risk of partial (or worse) collapse from falling or dislodged masonry. This has significant implications for human life but also for the urban environment and economic health of building owners, managers, and insurers and for local and national economies. This risk can mainly be attributed to the slow deterioration of masonry under atmospheric and other environments and the corrosion of so-called wall ties. Wall ties are relatively thin pieces of steel that tie the outer leaf of masonry walls to the stabilized inner leaf. The problem is likely severe for scenarios such as cyclonic and earthquake events, as they cause area-wide damage and the potential wide-spread loss of human life—losses that could be prevented by timely intervention. This paper reports on the in situ inspection of two case study buildings and the data obtained from controlled wall tie corrosion field trials, which are used to develop predictive models of structural response. These models will inform practical tools that will be developed for building assessment, cost-effective monitoring, and rectification, assisting in the management of existing masonry buildings.

Elaboration of a new calculation procedure of hydrocarbon deposit layer thickness in fuel channels of heat engines and power plants

The article is devoted to theoretical research connected with elaboration of a new calculation procedure for hydrocarbon deposit layer thickness. A common problem of deposit formation in heat engines and power plants is thoroughly investigated. In addition, the wall composition, temperature, time and a number of life cycles, etc. are mentioned as key factors that have direct influence on this heat phenomenon. The paper describes thermophysical properties of deposits in fuel feed systems of different engines. The literature search and analysis did not reveal any similar procedures of calculation of hydrocarbon deposit layer thickness that could be connected with electrical properties of a wall or a deposit. The paper presents new equations for calculating the deposit formation thickness and rate based upon thermal and electrical nature of this process. These new equations led to elaboration of the new calculation procedure of hydrocarbon deposit layer thickness on a metal wall for any fuel channel of a heat engine or a power plant based on liquid hydrocarbon fuel or coolant. The new calculation technique was verified by experiments in aviation kerosene boiling in volume, which clarified special features in the application of new equations. Owing to the universal character of the proposed technique, it can be used for calculating the deposit formation virtually in all the known heat engines and power plants, for various operating conditions, for different metal wall compositions, at various fuel flow rates and pressures, temperature regimes inside fuel-feed and cooling channels.

High Speed PIV Measurements in Water Hammer

An experimental study addressing the challenge to measure relaxation coefficient of very fast phenomena such as water hammers is presented. An acrylic projectile containing water is accelerated and impacts a metal wall creating a water hammer. State of the art laser measurements techniques will be deployed in order to achieve such goal. A compressed air custom built cannon is used to accelerate the projectile and create the impact leading to the water hammer. First experimental results for Shadowgraphy and PIV measurements are presented and discussed with focus on the future development for the presented facility.

HIGHER RADIAL MODES OF AZIMUTHAL SURFACE WAVES ABOVE THE UPPER-HYBRID FREQUENCY IN CYLINDRICAL WAVEGUIDES PARTIALLY FILLED BY PLASMA

Azimuthal surface waves (ASWs) are known to be eigen waves of cylindrical metal waveguides partially filled by magnetoactive plasma. Zeroth radial modes were under study earlier. Their dispersion properties are known to be significantly influenced by the plasma column properties: its particle density, external axial static magnetic field, geometric dimensions, – rather than properties of the dielectric layer which separates the plasma column from the metal wall. Application of higher order ASWs in the low-frequency range was shown earlier to make it possible to get advantage of exciting ASWs with higher frequency than in the case of zeroth order ASWs without no change in the waveguide design. The present study generalises those investigation for the case of the waves above the upperhybrid frequency.