In this article the results of experimental research of kinematics and the dynamics of horseshoe vortex structures, wake vortices and lateral jet flows, formed around and inside the pile group of three-row grillage, set on a flat rigid surface and sand soil, are presented. Visualization of flow is conducted using water soluble coatings and contrast substances, introduced into the stream. The fields of velocity, pressure and shear stresses around and inside the pile construction were investigated using the miniature sensors of the velocity, dynamic pressure and pressure fluctuations. The place of formation and features of development of large-scale horseshoe vortex structures and wake vortices, and the hydrodynamic characteristics of the vortex and jet flow were determined. The space-time correlation and spectral characteristics of the velocity and pressure fluctuations were measured. The scale of the coherent vortex structures, their frequencies of rotations and oscillations, convective velocities and direction of transfer were determined. The three-dimensional spectrograms and correlograms of vortex and the jet flow about and inside the three-row pile grillage were obtained.

The results of experimental studies are presented in order to study the features of the formation of separated and vortex flows in the vicinity of a transversely streamlined cylinder on the surface of a hydraulically smooth rigid surface and to determine the space-time characteristics of sources of wall pressure fluctuations. The studies were carried out in laboratory conditions on transversely streamlined cylinders, which were located on a rigid surface. The field of wall pressure fluctuations was measured by a group of miniature piezoceramic pressure fluctuation sensors, which were installed flush with the streamlined rigid surface in front of the cylinder and in its wake. The research results were processed and analyzed using the mathematical apparatus of the theory of probability and mathematical statistics. The spectral and correlation characteristics of the separated flow in the vicinity of a transversely streamlined cylinder are obtained.

The paper presents the results of experimental studies of the space-time characteristics of the velocity and pressure field inside a hemispherical dimple on a flat surface. The features of the formation and development of vortex structures generated inside the dimple, as well as their interaction with the streamlined surface of the dimple and the boundary layer were established. Integral, spectral and correlation characteristics of the field of velocity, dynamic and wall pressure fluctuations were obtained. The velocities and directions of transfer of large-scale vortex structures and small-scale vortices inside the dimple were determined. The frequencies of rotations and ejections of large-scale vortices, the frequencies of oscillations of the vortex flow inside the dimple and self-oscillations of the vortex structures of the shear layer, their subharmonics and harmonics of higher orders were established.