Fluid mechanics
The fluid mechanics or fluid mechanics or fluid mechanics is the study of the physical behavior of fluids. It is also important in theoretical engineering, which finds its foundations in continuum mechanics, that of classical physics.
Subregions
The fluid dynamics is divided into a number of subject areas, which deal with different aspects of fluids:
- Fluid statics is the study of ( approximately ) stationary fluids Aerostatics considered: the stratification of the atmosphere and Earth's atmosphere at rest.
- The pressure distribution in quiescent liquids,
- The forces on vessel walls,
- The formation of free surfaces,
- The buoyancy and
- Stability of the floating bodies.
- Fluid dynamics is the study of fluids in motion Looking specifically at the aerodynamic behavior of solids in gases, for instance in the air of the atmosphere
- Hydrodynamics (also partly used as a general term in the sense of fluid dynamics)
- MGD into account the electrical and magnetic properties of liquids, gases and plasmas and also examined: the movement under the action of the fields generated by the medium itself,
- The motion in external fields.
Description of the flow
Within the fluid dynamics applications are described using a number of indicators that represent different aspects of the fluids. These properties are listed below:
- Behavior of the fluid incompressible flows
- Compressible flows are discussed in detail in the gas dynamics the Prandtl-Meyer flow
- The theory of characteristics
- The phenomenon of shock waves and the interactions of multiple shocks or Prandtl-Meyer flows
- Unsteady flow
- Stationary flow
- Laminar flow
- Turbulent flow
- Inviscid flows and
- Viscous Flows
- Flows in pipes
- Flows in open channels
- Seepage
According to these properties and the specific application, different calculation paths are used in fluid dynamics to describe a flow:
- The potential flows and
- The eddy currents ( flow instabilities )
- The streamline theory and
- The pipe flow
- The boundary layer flow,
- The similarity theory,
- The multiphase flow: In the area of multiphase flow currents are examined, which portions of liquids, gases and solids may have ( eg dust). Because of the interactions of the phases to each other (eg slip, phase transitions ) a calculation of the physical quantities of the multiphase flow is usually only possible by approximation. A distinction is made between: separated flows
- Disperse multiphase flows
Mathematical models and description of phenomena
Flow processes of fluids described by the Navier -Stokes equations, which consist of partial differential equations, and in general, however, are only for special boundary conditions or solved numerically. They contain the flow descriptive variable speed, pressure P, density and viscosity as a function of location (x, y, z) and time t. The determination of these parameters is done alternatively with the laws of conservation of mass, momentum and energy, in the most general case of a thermal equation of state ( in which case also the temperature T must be considered ), as well as a constitutive law of the flow medium.
Scope
Applications to meet, amongst others in the following areas:
- Aerospace
- Automotive industry
- Shipbuilding
- Boat building
- Engineering
- Energy Technology
- Process engineering
- Chemical Industry
- Meteorology
- Oceanography
- Geophysics
- Astrophysics
- Building aerodynamics
- Supply Technology
- Hydraulic