CE 2200 Lecture : Lecture1920
Document Summary
Objectives: to understand dimensional analysis and basic similitude principles involved in the physical model design. If an equation truly expresses a proper relationship between variables in a physical process, it will be dimensional homogeneity; i. e. , every additive term in an equation must have the same ___________. Example: bernoulli"s equation for incompressible flow p. Each term, including the constant, has dimensions of length. The equation is dimensionally homogeneous and gives proper results for any consistent set of units. Dimensions and units: for a physical variable, the dimension is unique while the units can be expressed in several ways. For example, the unit of a length [l] can be meter, centimeter or foot. For most engineering problems the basic dimensions are mass (m), __________, and ___________. Any true physical equation can be expressed in terms of dimensionless variables. We let uppercase greek letter denote a nondimensional parameter, e. g. , reynolds number re, Froude number fr , drag coefficient, cd, etc.
