10.9 Postprocessing for a Single Rotating Reference Frame

When you solve a problem in a rotating reference frame, you can plot or report both absolute and relative velocities. For all velocity parameters (e.g., Velocity Magnitude and Mach Number), corresponding relative values will be available for postprocessing (e.g., Relative Velocity Magnitude and Relative Mach Number). These variables are contained in the Velocity... category of the variable selection drop-down list that appears in postprocessing dialog boxes. Relative values are also available for postprocessing of total pressure, total temperature, and any other parameters that include a dynamic contribution dependent on the reference frame (e.g., Relative Total Pressure, Relative Total Temperature, Rothalpy).

When plotting velocity vectors, you can choose to plot vectors in the absolute frame (the default), or you can select Relative Velocity in the Vectors of drop-down list in the Vectors dialog box to plot vectors in the rotating frame. If you plot relative velocity vectors, you might want to color the vectors by relative velocity magnitude (by choosing Relative Velocity Magnitude in the Color by list); by default they will be colored by absolute velocity magnitude. Figures  10.9.1 and 10.9.2 show absolute and relative velocity vectors in a rotating domain with a stationary outer wall.

Figure 10.9.1: Absolute Velocity Vectors

Figure 10.9.2: Relative Velocity Vectors