We investigate the analogy between circumstellar disks and the Taylor-Couette flow .
Using the Reynolds similarity principle , the analogy results in a number of parameter-free predictions about stability of the disks , and their turbulent transport properties , provided the disk structure is available .
We discuss how the latter can be deduced from interferometric observations of circumstellar material .
We use the resulting disk structure to compute the molecular transport coefficients , including the effect of ionization by the central object .
The resulting control parameter indicates that the disk is well into the turbulent regime .
The analogy is also used to compute the effective accretion rate , as a function of the disk characteristic parameters ( orbiting velocity , temperature and density ) .
These values are in very good agreement with experimental , parameter-free predictions derived from the analogy .
The turbulent viscosity is also computed and found to correspond to an \alpha -parameter 2 \times 10 ^ { -4 } < \alpha < 2 \times 10 ^ { -2 } .
Predictions regarding fluctuations are also checked : luminosity fluctuations in disks do obey the same universal distribution as energy fluctuations observed in a laboratory turbulent flow .
Radial velocity dispersion in the outer part of the disk is predicted to be of the order of 0.1 km/s , in agreement with available observations .
All these issues provide a proof of the turbulent character of the circumstellar disks , as well as a parameter-free theoretical estimate of effective accretion rates .