VDI 4675 Blatt 1:2012-09 (R2017)

The aim of the guideline is to describe a method by which inhomogeneous flow fields can be averaged in such a way that the field quantities subjected to the averaging process assume values which are compatible with all principles of physical balancing when the system as a whole is taken into account. The method can be applied not only with temporally but also with spatially inhomogenous flow fields. Balance based averaging is the only method which is adequat for carrying out a step-by-step reduction of high quality data for unsteady 3D-flow fields to phase-lock unsteady 1D-flow fields.