Defining an Expression
Expressions are mathematical descriptions that typically contain intrinsic functions, such as sin(x), and arithmetic operators, such as +, -, *, and /, as well as defined variables. For example, you could define: x_size = 1 mm, y_size = x_size + sin(x_size). Defining one variable in terms of another makes a dependent variable. Dependent variables, though useful in many situations, cannot be the subject of optimization, sensitivity analysis, tuning, or statistical analysis.
The Constants tab of the Project Variables window lists the available predefined constants, which can not be reassigned a new value.
Name |
Value |
Description |
abs0 |
-273.15A |
Absolute zero(°C) |
boltz |
1.3806503E-023 |
Boltzmann constant (J/K) |
c0 |
299792458 |
Speed of light in vacuum (m/s) |
e0 |
8.854187817e-012 |
Permittivity of vacuum (F/m) |
elecq |
1.602176462e-019 |
Electron charge (C) |
eta |
376.730313461 |
Impedance of vacuum (Ohm) |
false |
0 |
Boolean False |
g0 |
9.80665 |
Acceleration due to gravity of Earth (m/s^2) |
mathE |
2.718281828 |
Euler's number (Napier's constant) |
pi |
3.14159265358979 |
Ratio of circle circumference to diameter |
planck |
6.6260755e-34 |
Planck's constant (m^2*kg/s) |
true |
1 |
Boolean True |
u0 |
1.2566370614359e-06 |
Permeability of vacuum (H/m) |
Numerical values may be entered in Ansys’ shorthand for scientific notation. For example, 5x107 could be entered as 5e7.
Related Topics
Defining Mathematical Functions
Using Valid Operators for Expressions
Using Intrinsic Functions for Expressions