Simcenter Madymo Introduction of Madymo Tank Test Analysis

Content

• Purpose
• Inflator tank test
• MTA method introduction
• Appendix
  • Example of tank test validation

Purpose

Taking advantage of Simcenter Madymo MTA (Madymo Tank Test Analysis) method, convert inflator tank test data to gas mass flow rate and temperature data, which are used as the input of Madymo inflator model.

Inflator tank test

• Tank test data will include

  • Pressure vs. time (must)

  • Temperature vs. time (optional)

  • Gas mixture

  • Total gas mass

The following figure shows the tank for the inflator test and its general test setup. 

Tank test analysis method

There're 5 ways of MTA method solution in total.

• Ptank only                =>     Average Temperature Solution
• Ptank and Ttank      =>     Tank Temperature Solution
• Ptank and Pinfl        =>     Critical Flow Solution (for large passenger bag inflators and also stored gas / heated gas inflators)

•                       or       =>      Linear Burn Rate Model (for driver airbag inflators and some passenger airbag inflators)

• Ptank and Fthrust    =>      Thrust-based Solution

Each of MTA solutions requires different input data of the tank test and the generated mass flow rate and temperature data differs as shown in the figure below.

Next, the Average Temperature Method will be introduced to show the generation of mass flow rate.

• Input in template file
  • Tank volume
  • Pressure
  • Gas mass
  • Gas mixture
• Output
  • Mass flow rate
  • Average temperature

The relevant details of the input template file is shown in the following figure. 

Procedures of the converter of gas mass flow rate:

• From the start of the template file which is located in Madymo installation folder 'C:\Program Files\Madymo\madymo_2406\share\appl\mta\appl1.dat'，replace the data mentioned above with your tank test data in the template file and then save as appl2.dat;

• In Command window,Type in madymo* -mta appl2.dat; （Note: * = version, eg. 2406)

• After completed, the output files appl2.min & appl2.out will be generated;
• The output file appl2.min can be opened by XMADgic, and it includes the mass flow rate and temperature data which are required for  Madymo inflator model.

Appendix: Example of tank test validation

• The process of tank test validation

• Example of validated results
  • Maximum pressure and timing
  • Rise rate