In 20-sim, to every constant, parameter and variable a quantity may be assigned. Well known quantities are for example position, velocity, time and energy. 20-sim will use these quantities to check the validity of (basic) equations. The value of a quantity can be expressed in a specific unit. The quantity time can for example be expressed in the unit second or in the unit minute:
|
quantity |
unit |
multiplication to SI unit |
|
Time |
second (SI unit) minute hour year |
1 60 3600 31556926 |
|
Position |
meter (SI unit) foot inch yard |
1 0.3048 0.0254 0.9144 |
In 20-sim a quantity can be expressed in every desired unit. To prevent conversion problems, internal calculations are always performed in standard SI-units. Therefore non-SI units are stored with a multiplication factor. When a variable has a unit, the unit can also have common engineering prefixes. For example, a parameter m {kg} with a value of 0.1 can be selected in the Parameters / Initial Values Editor. If you click on the unit, you can select other units to enter the mass.
You can use the units in the Parameters / Initial Values Editor to select a desired unit.
You can enter new quantities and units in the Domains, Quantities and Units Editor.