The Problem
Input
Grid
Speed
Efficiency
Check
Output
Read a bitmap

When a scanned image in bitmap format is used as source of the data, then three blinking symbols (a square and two triangles) for the definition of the origin and the maximum values of the x- respectively y-axis will appear on top of the image.

These symbols are placed as required with the mouse, and the corresponding true values for mass flow and pressure ratio are entered as numbers. This correlates the coordinate system on the screen with the true coordinate system.

When the coordinates have been defined, then the table on the left part of the figure below will be filled with numbers just by clicking on points on the speed lines in the bitmap.

Efficiency may be given as graph in two formats:

  • Efficiency as y-axis and Corrected Flow as x-axis
  • Pressure Ratio as y-axis and Efficiency as x-axis
Reading efficiency from a bitmap