# Parametric distribution for Linux

## Introduction

This chapter discusses the establishment of a

**parametric distribution in Flux for Linux OS**. The distributed computing allows the user to save computation time while distributing several independent configurations of a same Flux project. For example a Magnetic Transient project may be distributed regarding differents values of parameters such as the geometrical parameters (size, shape etc...) or physical parameters (supply current values, speed...) varying in the scenario. Several projects will run at the same time simulating all those configurations, the main parameter of a distributed computation is the following one:- The number of cores (i.e the number of running Flux in parallel)

## Example of application

To show the interest of the parametric distribution, let us consider a project
modeling a three-phase, eight-pole permanent magnet synchronous machine (PMSM) using
a Flux 2D Transient Magnetic application. This simulation will be controlled by the
angular position of the rotor from 0 to 90 degrees with imposed speed which is a
time dependant scenario. During the parametric distribution Flux will compute the
results for all the parameters combination for each time step.

The goal is to do a parametric distribution over two parameters:

According to the previous table, the number of steps to solve is about 2525
(5*5*101) with five values for the speed, five values for the magnet outer arc over
a scenario with 101 time steps.

- The speed which is declared as an I/O parameter controlled by the scenario and that is used by the rotating mechanical set
- The shape of the magnet with the magnet outer arc value
*α*setted with a geometrical parameter as depicted below.

Magnet outer arc α (degrees) | Speed (rpm) | |
---|---|---|

Minimum value | 130 | 1300 |

Maximum value | 170 | 1700 |

Step value | 10 | 100 |

Note: Be aware that the time
steps cannot be separated in concurrent Flux, a strong time relation between the
steps is required to solve a Transient Magnetic application. This relation does
not exist in the Magneto Static application.

The results yielded by using a different

**Number of concurrent Flux**setted in the**Distribution manager**while solving the same scenario with 2525 time steps. The computation time with only 1 concurrent Flux (sequential computing) is considered as the reference and is setted to 100% of the solving time are plotted in Figure 3.