Russian original abstracts
The computational fluid mechanics experiments by using of a digital computers is based on a finite differences schemes, which applied hydrodynamic values by nodes of computation grid and the distance between item points is impossible to admit as infinitesimal ones, so approximation of hydrodynamic fields of computational schemes are not smooth and not continuous.
Designing of mathematical methods at the beginning oriented for solution to the fluid mechanics of the finite differentials, allows not only to analyze correctly the differential approximations properties for differential equations, but it is the foundation for complex researches of fluid reology as well and it can be used for problem establishment and practical realization of fluid mechanics computational experiments.
The stratification of computational processes by the physical parameters is set into the tensor definition of fluidmechanics laws basis, when external forces and reactions summoned by them should be defined by different tensor bases (coordinate systems). Invariants and eigenvectors of such the tensor of connection between the bases define the internal reological properties of liquid particle and the accumulation factors (closing) inside of the external energy. Principles of the computational operations within the tensor area are fundamental laws of mechanics which give strict description of the reological and dynamics flow properties.
In particular within the fluid flow area where the degeneration of II-range tensor basis, is taking place practically might be observed the vortex, free surface separation or cavity. Respectively control of a conditionality of the matrix which is forming the tensor of the fluid properties might allow as to provide the authenticity of computational experiments, so to carry out a opportune transfer to particular problems or others including empirical patterns.
It is interesting that using formal tensor laws which are applied for viscous compressible either it is easy to determine the elementary particles including ones which take part in dynamics of intranuclear substance reciprocity; by the same positions to define thermal, electromagnetic, mechanical and gravitational fields and reciprocity principles of the physical objects.
The instrument for tensor laws construction might be used for computational processes design of evident (canonic) form that might provide the parallel computational processes till the each of a single fluid particle and also it sets conditions for automatic reconstruction of computational schemes possibility, depending on the current fluid mechanics or flow reology properties.
Okhotsk sea is a large half-closed water area, and it is unique region for a natural and computational researching for the tidal and flow processes.
The target of the current project is creation of mathematical models and realization of oceanological computational experiments which is capable to simulate the real tidal and flow conditions in the Okhotsk sea and also to predict simulate off storm surge and tsunami.
Project goals to study the numerical scheme properties, to analyze the empirical dependencies which are characterizing the bottom friction, surface strains from storm winds and other dynamic and algorithmic particularities of computational simulation for tidal and flow. As results of the performance mathematical models and their program realizations would be created and tested in which peculiarities of the fluid mechanics processes simulation in the Okhotsk sea would be taken into account, and procedures and criterion for the direct numerical simulation of the tidal modes within other half-closed seas would be elaborated.
The project was supported by Russian Foundation for Basic Researches, grant ¹ 97.05.66037
The tsunami is dangerous sea phenomena, which admits the possibility to organize the actions for the peopling evacuation with the lead time from a few minutes to hours.
Fluid mechanics of tsunami shall be defined as high-frequency long wave process, the direct numerical simulation of which requests the large computational resources to meet the approximation criterion.
The current project solves the problem for complex researches of special information systems and computational experiments which have to be adapted for operative information receiving from coastal hydrometeorological stations observation and to carry out in full accordance to operational tsunami warning service regulations.
The project was supported by Russian Foundation for Basic Researches,
grant ¹ 97.01.96010.
Drilling on the Sakhalin shelf perform during the summer navigation. In autumn oil-rigs returning to south area of the Okhotsk sea and while they are going over a sea they risk to come upon the force of the hurricane storms. When the storm rolling the oilrig captain has an optimal solving from contradict conditions between decreasing of upper deck flooding and minimization of rolling and angle acceleration on rolling and pitching
It is proposed to automatize all the navigators calculations related with estimations of loading, stability, rolling and rolling parameters of the oilrig. Navigators computer must be connect with the data units of wind velocity and direction, data from compass and inclinometer. Such the computer unit will allow in automatic mode to control the seakeeping and safety conditions on the storm ways, and will allow in a short time to estimate different options for rig loading, which will be promoting for decreasing of the dangerous effect of the storm wind and clean breach.
The analogous work modes of the navigators computer should provide the steady of oilrig being on the ground, when during the oil production process the loading modes as alternate, that the static steady of the rig might be broken under the effects of stream, storm and waving.
The navigators information computational complex should include a computer which will receive the information from navigational instruments: compass, velocity log, echo depth sounder, gyro-compass, GPS and data units of main engines, from a weather system the water and air temperature, wind direction and velocity, wave height characteristics. In that case with the help of computational algorithms for the proper rolling and ship stability parameters might be identified using previous records of storm navigating mode; the recommendations about maximum speed achievement methods, minimizing of rolling and other seakeeping characteristics required by duty navigator would be elaborating.
Such work has the most important fundamental value for researching the seaworthiness problems will allow to rise the level of navigation convenience and security, will allow to enlarge the ship operation efficiency during the storm sailing.
Seakeeping of the ship is a researches depend on the really marine practice and on the human experience based on the captains solving for a different seagoing conditions. Project concludes the following three parts:
1. The analysis of the historical decisions at designing the most seaworthy form of the case of the ship, comparison to modern experience of navigation and seafaring.
2. Complex of analytical researches and computing experiments, which make a theoretical basis of designing by best on seaworthy qualities of the form of the case of the ship;
3. Complex of seaworthy tests in the towing basin, when for an estimation of critical modes of navigation, in common with the special prepared experimental model the tests of base models were carried out, on which in the world literature there are extensive items of information. In conclusion of experiments the tests of modes of safe navigation were executed, in which the model was tested on the supercritical for a traditional vessel regimes of sailing and safety of emergency swimming without a course.
The work requires recurrence of all computing experiments with use of modern computer facilities, and also which contain in detailed study of experimental records on paper carriers, speed up and calibrate curves, indications of accelerometer, gyro-horizon and wavegraphs, complex tests, received at performance in the towing basin.
By results of computing experiments and towing tests the qualitative conclusions about an opportunity of essential improvement of seaworthy qualities of the ship adapted to navigation in a storm condition were received thus, practically in all modes of storm navigation the new model showed the essential superiority over the existing projects of the form of the case of the ship.
§ 1. Technician-history analysis of ship seakeeping
(c)85-98, Vasily N. Khramushin, Saint-Petersburg - Yuzhno-Sakhalinsk
The performance of the current project is necessary for technical improvement of the tool facilities using in the Sea Department, hydro-forecast services and in the Tsunami Warning Center of the Sakhalin Hydrometeorology service.
The topicality of project is specified by the point that present services carry out using obsolete paper technologies which it is impossible to use for efficient solution to the operative problems related with the sea environment control.
During automation process of the routing tasks in sea departments of the Sakhalin Weather Service the formats of data and operative information should be developed which at further time might be used at performance the oceanological researches involving international projects.