Motor Report

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The motor report is a clean, printable summary of a motor and its simulation on a single page (more when it has exhaust products or a case) - the headline performance numbers, the full grain stack, the motor and nozzle configuration, and the Kn, pressure and thrust curves - that you can save as a PDF or print. It is the thing to hand someone who asks "what is this motor", to file alongside a static test, or to keep with your records for a certification or a build.

Nothing in the report is new analysis: it is the same simulation shown in the main window, laid out for paper rather than the screen.

Creating a report

Open a motor, run the simulation, then choose File → Print / Report... (or press Ctrl+P, or click the Print / Report button on the toolbar). A preview window opens showing the report exactly as it will print, with two actions:

  • Save PDF... - writes the report to a PDF file and opens it in your PDF viewer. Available on Windows, macOS and Linux.
  • Print - sends it straight to a printer. Windows only; on macOS and Linux use Save PDF... and print from your PDF viewer, which does the same job.

The report uses whichever units the rest of BurnSim is set to, imperial or metric, so it matches the numbers you have been working with.

Printing and PDF export need a license - a trial can design motors and run unlimited simulations but cannot print or export (see License).

What the report contains

A single page, top to bottom:

  • Header - the motor name and its designation (for example M-1302 (12% M)), the date, and the motor file name.
  • Notices - any [Critical], [Warning] or [Info] messages the simulation raised, printed above the numbers so they are read first, exactly as the Results panel shows them.
  • Simulation Summary - the headline results and the design behind them, including:
    • total impulse, burn time and the Kn init / max / min / avg;
    • peak pressure (MEOP), peak and average thrust, and delivered specific impulse;
    • propellant mass, volume loading, initial free volume and L* (both include the chamber ullage, when it is entered);
    • web thickness, port/throat area ratio, peak mass flux and mass flow;
    • nozzle throat and exit diameter and the expansion ratio.
  • Configuration notes - whether erosive burning is on, the nozzle divergence loss and half-angle, and the modelled igniter charge (by burning surface and by free volume).
  • Grains - a table of every grain in the stack (length, diameter, core, inhibited ends, type and propellant), with the total propellant length and core L/D.
  • The graph - Kn, pressure and thrust plotted against time, the same curve as the main window.
  • Footer - the BurnSim version that produced the report and www.burnsim.com.

With a commercial license and a propellant that has a thermochemistry recipe, a second page carries the exhaust products as two tables - at the nozzle exit and fully burned in air - each with a total row, and page 1 says so in one line. On any other license the report stays one page.

When the motor has a case defined on the Case tab, the report gains one or two case pages after the motor page (since 4.0.0.25). They carry the standing notice that these are hand calculations and not a safety assessment, then the result (design pressure, burst pressure, MEOP and margin), a table of every check with its allowable pressure, the inputs, the notes and the not-checked list. If the grains do not fit the case, that is said too. A case check that refused to run prints the reason and nothing else. The formulas themselves are in Show the working on the Case tab, not in the report. A motor with no case gets the report it always did.

See also

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