Fluid mechanics

Fluid mechanics is the branch of physics concerned with balance and movement of fluids and fluid systems under the influence of external and internal forces. The fundamental difference between the rigid body and the fluid is the mobility of the molecules. Rigid body moves as a set of mass points of a given shape, the fluid does not have its own shape and, contrary to the rigid body under the action of forces irreversibly deforms, its particles are brought into motion, and flow in current bounded by solid walls or interface (level).  The goal of fluid mechanics is to explain phenomena and processes occurring in fluids and fluid systems using physical laws and predicting the behavior of fluids and fluid systems in certain conditions, to determine the distribution of fluid properties, i.e. pressure, density, velocity, temperature, concentration, etc. and possibly changes in these variables over time in different locations within the liquid.  

Research of two- and multi- phase systems flow, including the movement of solid particles in a fluid is the theoretical basis of many engineering disciplines. The study of fluid and fluid systems mechanics at the Institute of Hydrodynamics ASCR , v. v. i., is focused on theoretical and experimental investigation of the flow of suspension, the movement of particles and sediment in close and open conduits, tanks and reservoirs, mixing processes of fluid systems, as well as on mathematical modelling and numerical simulation, calibration and verification of flow models based on the results of experimental research, on experimental methods, and on analysis of a turbulent flow.

With the development of new techniques and technologies are increasing the possibility of experimental research on a range of non-invasive methods and methods for understanding the structure of current and local values , especially vector velocity and density. Experimental methods, similarly like numerical methods have developed in a separate area of knowledge and it is necessary to pay them adequate attention.