Why water is called the ideal liquid

Ideal liquid

As ideal liquid In physics and in hydrostatics and hydrodynamics, one describes the idealized model representation of a liquid. Although it represents a great simplification, many physical processes can already be understood and mathematically described with this model.


Except for the internal frictionlessness of the liquid molecules, the properties of ideal liquids are not uniformly defined.[1] This means that ideal liquids are not viscous. Due to the lack of friction, no energy is lost mechanically in the ideal liquid, whereas in real liquids, energy is converted into heat through friction forces. In addition, an ideal liquid has no resistance to changes in shape and can therefore be used as a ideally fluid be viewed in contrast to the solid body, which resists any change in shape.[2] The following defining properties can also apply:


The same hydrostatic pressure prevails everywhere in ideal liquids. Is applied to an ideal liquid (in a container closed all around) via a movable piston with the surface A. by a force F. a piston pressure is exerted, this pressure spreadsp inside and on all sides at the same time and evenly. It applies

$ p = \ frac F A $

Because the liquid is at rest, the pressure exerts an orthogonal force on each interface that is proportional to the area.

Individual evidence

  1. Tsutomu Kambe: Elementary fluid mechanics. World Scientific 2007, ISBN 978-981-256-416-0 (accessed December 14, 2011) P. 26
  2. Karl Wieghardt: Theoretical fluid dynamics. Universitätsverlag Göttingen 2006, ISBN 978-3-938616-33-8 (accessed on December 14, 2011) P. 12

See also