Effects of fuzziness on dynamical similarity and Reynold's number

By formulating the basic principles of dimensional analysis method in fuzzi fied form it is possible to discuss the values of the characteristics varia bles and their dimensional representation in physical quantities. This pape r gives a theoretical justification for the Reynold's number as a dimension less fuzzy physical quantity. Special attention is paid to the possibilisti c criteria for dynamical similarity in fuzzy sense which are based on the R eynold's number, where the density of the fluid, the characteristic length of the body immersed in the fluid, the fluid velocity and the fluid dynamic viscosity are considered as crisp quantities. (C) 2000 Elsevier Science B. V. All rights reserved.