Cuboid Container Research Articles

Dynamic simulation of hydrodynamic model of drum level wave action and sloshing

In order to build the model of the drum level wave action and sloshing, based on the method of modularization modeling, the hydrodynamic model of drum level wave action and sloshing was developed, and dynamic simulation researches were carried out based on the model. The results indicate that both drum level and drum length have functional relations with period of drum level wave action and sloshing. When the drum level decreases or drum length increases, the period of drum level wave action and sloshing increases, density of liquid and number of sub-module division have little influence on the period of drum level wave action and sloshing. The model was validated by the analytical solution theory of liquid’s wave action and sloshing in cuboid container, and the 3D graphics of drum level wave action and sloshing was also obtained. The model can dynamically reflect the rules of wave action and sloshing of water in the container exactly.

A new heuristic algorithm for cuboids packing with no orientation constraints

The three-dimensional cuboids packing is NP-hard and finds many applications in the transportation industry. The problem is to pack a subset of cuboid boxes into a big cuboid container such that the total volume of the packed boxes is maximized. The boxes have no orientation constraints, i.e. they can be rotated by 90 ∘ in any direction. A new heuristic algorithm is presented that defines a conception of caving degree to judge how close a packing box is to those boxes already packed into the container, and always chooses a packing with the largest caving degree to do. The performance is evaluated on all the 47 related benchmarks from the OR-Library. Experiments on a personal computer show a high average volume utilization of 94.6% with an average computation time of 23 min for the strengthened A1 algorithm, which improves current best records by 3.6%. In addition, the top-10 A2 algorithm achieved an average volume utilization of 91.9% with an average computation time of 55 s, which also got higher utilization than current best records reported in the literature.

Ultrasonic Characterization of Thermal Distribution in Vicinity for a Cylindrical Thermal Lesion in a Biological Tissue

The study considers an ultrasonic characterization on the thermal distribution in vicinity for a cylindrical thermal lesion formed in a biological tissue. The cylindrical heat source is made of a standard nichrome wire with the diameter of 1 mm. The wire was inserted inside a pork muscle housed in a cuboidal container made of perspex. The heat is conducted radially outwards from the wire to the surrounding tissue. Thermal distribution near the heated wire was predicted by numerically solving a bioheat transfer function using FemLab (Comsol, Inc.). As the wire temperature was raised from the environmental temperature 20 °C to more than 80 °C in steps of 5 °C, ultrasonic B-scan images were acquired at each temperature. We assessed the feasibility of detecting the lesion boundary using changes in echogenicity, changes in centroid frequency due to attenuation, tissue moving characteristics resulting from changes in the speed of sound, and elastograms. These observations will be of use in improving ultrasonic monitoring and guiding in HIFU surgery and thermo-therapeutic process in general.

Performance characteristics of pebble flow for pebble divertor

The pebble divertor concept is proposed for the high-power density fusion reactor. In this system, a large number of multi-layer pebbles are dropped in the divertor region to form the pebble curtain as the divertor plate. The multi-layer pebble consists of three layers, i.e. kernel, a plasma facing layer and an immediate tritium permission barrier. The performance characteristics of the pebble flow are related to flow rate and flow pattern for shielding the incident particle flux. In this study, we have studied fundamental designs of the dropping system. The dropping system consists of a container with the single slit at the bottom. The pebbles are stored in the cuboid container. In the experiment, the dependence of the flow rate of the pebble on the slit width is observed. Al 2O 3 pebbles and active carbon pebbles were used at the point of view for mechanical performance instead of using the multi-layer pebbles because the multi-layer pebble is very expensive now so that it is difficult to prepare a large number of pebble enough to perform the experiment. In the calculation, we estimated the dependence of the flow rate on the slit width. The calculation results have been coincident with the experimental results. It is possible to estimate the relation between slit width and flow rate of the multi-layer pebble with SiC kernel. From this study, the pebble curtain can shield more than 90% of heat flux from core plasma when the slit width is more than 3 cm.

Analysis of the characteristics of crystal growth from solution under microgravity II. effects of various physical and geometrical parameters

A hydrodynamic model of crystal growth from solution under microgravity is analyzed. In this model, a cuboidal container is filled with the parent solution; a flat plate of seed crystal is chosen to form one wall of the container; its opposite wall is made of the material of solute source; the temperatures and the solute concentrations at the surfaces of these two walls are kept constant. The Navier-Stokes equation, the equation of convection-diffusion and the equation of heat transfer are numerically solved to calculate the flow field, solute transport, distribution of solute concentration and of temperature, growth rate of crystal and to study the influence of some geometrical and physical parameters and gravity level on them. The law of similarity of fluid mechanics is discussed. It is explained how to choose suitable geometrical and physical parameters and conditions of crystal growth to favor the growth of perfect crystal.

An analysis of the characteristics of crystal growth from solution under microgravity

A hydrodynamic model of crystal growth from solution under microgravity is analyzed in this paper. The crystal is considered in the form of a flat plate or strip placed on an inner face of cuboidal container which is filled with its parent solution so that the normal to the growth face of crystal is perpendicular to the gravity. The Navier-Stokes equation and the equation for convection-diffusion are numerically solved to calculate the flow field, solute transport, distribution of solute concentration and growth rate of crystal and to study the influence of gravity level on them. It is found that there is a boundary layer in the neighborhood of the growth face of crystal and the contribution of convection to the solute transport in the direction normal to the growth face of crystal is greater than that of diffusion even if in the boundary layer. There is no essential distinction between the results for the case of crystal plate and those for the case of crystal strip, but they varies more or less quantitatively.

Videotape observation of rats and mice during an exposure to 2450‐MHz microwave radiation

Rats and mice were observed in a microwave field to see if they would take behavioral action to minimize absorption of microwave energy by altering their orientation with respect to the E field. Individual rats were housed either in a cylindrical or in a cuboidal container, and mice were housed in a cuboidal container. They were placed in an anechoic chamber at 22 or 28°C for a one‐hour pre‐exposure period. During the second hour, animals were exposed to 2450‐MHz CW microwaves under far‐field conditions at a power density of 15 mW cm−2. Videotape samples of their positions were taken during a two‐hour session. Six rats and six mice were observed at each level of temperature and were scored for orientation relative to the electric vector or to the magnetic vector of the microwave field. Results indicate that 2450‐MHz CW microwaves did not cause animals to alter their position from that adopted in response to environmental or caging conditions. The specific absorption rate (SAR) in rats was not dependent on their orientation in the field. The SAR in mice was dependent on their orientation in the field but their orientation did not show changes interpretable as attempts to reduce microwave absorption. Containers reduce the SAR and, depending on shape, may reduce the orientation‐dependence of the SAR.