DEGREE OF FREEDOM AND RANDOMNESS OF AORTIC TURBULENCE.

There are two types of degrees of freedom of a random process. In this paper two types of characteristic frequency of turbulence were derived from the idea of the degrees of freedom. They were named the first characteristic frequency, K//1, and the second characteristic frequency, K//2. K//1 corresponds to the integral time scale of turbulence and K//2 can be regarded as a randomness factor of turbulence. K//1 and K//2 of the turbulence measured in the center of the canine ascending aorta were discussed. It was shown that K//2 was larger than K//1. It was found that K//2 was well correlated to the reciprocal of Strouhal number, but K//1 was not. So, it is suggested that the randomness of the aortic turbulence depends on the Strouhal number, but the integral time scale of the aortic turbulence does not.