The principle of similitude is a supplement to the

scientific method The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...

advocated by John Strutt (Lord Rayleigh) (1842–1919) that requires that any suggested scientific law be examined for its relationship to similar laws. The principle of similitude is very often used in scientific studies. For example, the study of blood flow known as

hemodynamics Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously mo ...

. This study sometimes require the modeling of blood vessels

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

. Here, the principle of similitude plays a huge role in ensuring the conditions of the model reproduces all aspects of behavior as the blood vessel in study. Various techniques are implemented when applying the principle of similitude. A well known technique is

dimensional analysis In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their base quantities (such as length, mass, time, and electric current) and units of measure (such as m ...

References

* Scientific method {{Sci-stub