Importing Test Data

While simulating motors is BurnSim's primary function, motors must be tested, and showing the actual test data alongside the simulation is how you validate a simulation and your propellant's characterization numbers. Test data is also what BurnSim's propellant characterization works from.

BurnSim imports pressure, thrust, or both. The simplest source is a spreadsheet, such as Excel, with a column of time followed by a column of pressure (and a column of thrust, if you have one), like the one below. It can also open a file directly: CSV and other delimited text, WinDaq recordings, RMTS firings and EasyMotor exports.

With the data in a spreadsheet, select the columns (as in the screenshot above) and copy them with Ctrl+C. Then open BurnSim and load the file for the motor you tested. In the Results panel at the lower right, click the Test Data tab, and then Import Clipboard (or Import File... to read a file instead).

A dialog opens where you say what each column is: time, pressure, thrust or unused, and the units it is already in. Columns of raw volts can be converted through a saved sensor calibration. The same dialog finds t=0 for you (or keeps your own times), and can keep only the firing out of a longer recording. Click Import and name the data set.

The imported pressure and thrust are graphed over the simulated curves, along with the thrust BurnSim works out from your measured pressure, and the data set is saved with the motor file.

The wiki's Test Data Tab page covers the import dialog, sensors and the rest in detail, and Propellant Characterization shows how to fit your propellant's burn rate from a firing.