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DO Vympel towing tank

DO Vympel is ready to provide model tests in its towing tank on the contractual basis.

 

Hydromechanics can not yet theoretically predict with required for practice accuracy cinematic and dynamic characteristics of flow conditions near ship surface and its resistance. For numerical estimation of those characteristics  model test is performed.

Towing tank on station of model tests of ships (SIMS) was opened in 1990 year. Pool basin has transverse section of rectangular shape. Main characteristics of basin are the following:

Length – 50,0 m;

Width – 5,0 m;

Basin bord height – 3,0 m;

Water level – 2,5-2,6 m;

Speed of model towing – up to 5 m/c.

 

For the purpose of model manufacture some workshops are arranged on the territory of SIMS provided by necessary machine-tool equipment allowing different joinery, mechanical, lathe, welding works. First model was tested in May of 1991 year.

In 1992 comparative tests of reference model in Vympel’s basin and  shallow-water basin of Krylov state research centre were taken place. On the basis of test results of the model taken as reference one for Vympel’s basin expert commission came to following conclusions:

-resistance curves formed in both basins in similar atmospheric conditions practically coincide

- effect of proportion of pool basin dimension to model dimension is minimal, doesn’t influence model resistance.

 

The tank has towing device of gravitational type; in addition it has a truss where carriage with instruments can move.

In one of end tank sides dock is aranged for model preparation for tests and wave breakers performed as grates installed with a slope to the water surface. Along the basin tank wave breakers are installed in the section of measurement area.

In tank dock part a facility for gravitational drive for model towing and device for  returning model to initial position is located.

 

 

In the opposite part of the tank a paddle-type wavemaker is located. Its construction allows generation of  regular waves of different size. In the same part, where wave maker and its gear are installed, gear for carriage towing is located.

For flow motion around underwater part of model survey illuminators are embedded in side walls of central portion of  tank at a height of 1,5 m from bottom.  In case of sufficient illumination it is possible to also photo the type of flow motion of model underwater part.

Control of towing carriage is performed from the control panel located in tank middle part.

For launching and recovery of model there is an      electric hoist.

 

Nowdays towing tank is hydrodinamic laboratory which provides research of ship models and facilitates the engineering.

Basin equipment allows to solve the following tasks:

- research of ship lines for minimization its water resistance

- research of seakeeping performance of designed ships including ship motions.

 

Standard model length for towing and sea-keeping trials is in range from 2,0 to 3,8 m. Models are done from foam plastic. Basin measurement system allows with sufficient degree of reliability estimation of model towing resistance and speed.

Non standard tests are also performed in towing tank.  For example in 2002  tests of wave-impact load on floating oil storage unit were done. The unit was anchored at a depth of 11,0 m (full scale) in the position of beam seas and at intermediate courses angles under seas. The system consisting of a floating oil storage unit abd 4 chain cables simulators fixed to the “ground” served as the test object. Condition of shallow water was specifically done for the test and that served as “ground”. Before the tests model calibration was performed, both statical and dynamical ones, in order to provide the similarity of model and original parameters, and also simulation of anchor chains models was performed.

Equipment and facilities of towing tank allow to measure the following parameters:

- model towing speed

- resistance of water to model movement

- model trim and heel

- seas parameters

- rolling characteristics.

 

Needless to say that constant improvement of experimental facilities of towing tank and implementation of automation means for the experiments are considered to be the main line of towing tank development.