Wyniki wyszukiwania - BazTech

1

Laboratory modelling and acoustic diagnostics of hydrodynamical processes

Chernov V.

Hydroacoustics

|

2008

|

Vol. 11

47-54

EN

In the present paper results of modelling of wind interaction with a water layer surface and research of the vortical structures arising downstream the flow around bodies are described. Results of the use of the method of acoustic diagnostics of spatially - periodic vortical flows are presented. At physical modelling in laboratory conditions wind was created with a low-velocity wind tunnel. The structure of an air stream and convective cells on water surface was investigated with the help of visualization. Some pictures of structures on the shallow sea surface are also demonstrated and discussed.

2

Cryptography and canonical number systems in quadratic fields

Fedoseev V., Chernov V.

Machine Graphics and Vision

|

2006

|

Vol. 15, No. 3/4

363-372

EN

This paper proposes an encryption method based on representation of messages in the canonical number systems (CNS) in quadratic fields. The essence of the encryption method is conversion of the representation of integers from the conventional number system to their representation in the CNS in a certain quadratic field. A sufficiently wide range of CNS with a given number of digits ensures resistance of the method to "accidental guessing" of the secret keys. Nonlinear nature of the conversion ensures its resistance to frequency analysis.

3

Observation of sonoluminescence and subharmonics

Didenkulov I., Kanakov V., Sanin A., Selivanovsky D., Chernov V.

Hydroacoustics

|

2005

|

Vol. 8

31-36

EN

In this paper we describe results of experimental investigation of multibubble somoluminescence. Experiments were done in acoustic resonator with water. It was found that sonoluminescence and subharmonics occurrence follows by each other when the amplitude of acoustic pump wave in the resonator increases and decreases. It was also observed a hysteresis effect.

4

Acoustic sensing of hydrodynamic vortex flow

Ezersky A., Gromov P., Soustov P., Chernov V.

Hydroacoustics

|

2005

|

Vol. 8

47-52

EN

We report the results of experiments of sound scattering by a vortex flow formed behind a grid of vertical cylinders placed in an air flow. The experiments were carried out in a low turbulence wind tunnel at a low Reynolds number. The vortex flow was formed behind a grid of 3-10 of hollow cylinders with the d=2 mm and length 30 mm. During the experiments we could change the gap between the cylinders g=L/d (where L is a distance between the cylinders surfaces) from 3 to 5. The experiments showed that at a certain value of g vortex flows behind different cylinders could synchronize and this effect could be easily detected by means of distant acoustic sensing. This result was also confirmed by means of direct measurements of velocity field of the vortex flow.

5

Sonoluminescence of water and biological liquids

Chernov V., Selivanovsky D.

Hydroacoustics

|

2003

|

Vol. 6

113--116

EN

In this work the results of experimental research of the sonoluminescence of water and biological liquid (plasma of blood) at different temperatures are described. The studied blood plasma was taken from normal and pathological patients. Sonoluminescence of water was found to decrease with a decrease in temperature. Samples of normal blood plasma produce sonoluminescence with approximately constant intensity at cooling. In contrast, sonoluminescence of pathological blood plasma increases with decreasing temperature. These results can be useful for investigations of the nature of sonoluminescence as well as for medical diagnostics.

6

Rotation motion of particles in sound field

Didenkulov I., Ezersky A., Selivanovsky D., Chernov V.

Hydroacoustics

|

2003

|

Vol. 6

167--170

EN

It is known that sound field produces longitudinal oscillation motion of medium. If there are floating particles in a medium those particles oscillate together with liquid. In this paper we consider dynamics of floating particles, which have rotational oscillations in acoustic field. This novel phenomena produces additional sound attenuation due to viscous damping. In the present paper this effect is analytically described. The expression for sound attenuation in suspensions of such particles and estimations of the value of the effect are obtained, and possible applications are discussed.