Description
Return signed and absolute cell Peclet numbers.
A dimensionless time-step ratio, free-diffusion scale or sampling weight assumes a particular model and data basis. Local bounds and factors can help diagnose a method, but accuracy, stability and statistical uncertainty depend on the complete algorithm and its assumptions.
Return signed and absolute cell Peclet numbers.
When to use this tool
Use Numerical Cell Peclet Term when checking the stated local stability, diffusion or sampling convention.
How to use the tool and how it works
- Enter velocity, cellWidth, diffusivity. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedPeclet, absolutePeclet. Use the output convention below.
Return signed and absolute cell Peclet numbers. Require cellWidth/diffusivity > 0; signedPeclet = velocity*width/diffusivity, absolutePeclet uses velocity magnitude.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| velocity | Velocity | Required. Finite number. |
| cellWidth | Cell Width | Required. Finite number; strictly above 0. |
| diffusivity | Diffusivity | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedPeclet | Signed Peclet | Required. Finite number. |
| absolutePeclet | Absolute Peclet | Required. Finite number. |
{
"input": {
"velocity": 2,
"cellWidth": 0.5,
"diffusivity": 0.25
},
"output": {
"signedPeclet": 4,
"absolutePeclet": 4
}
}Limitations and assumptions
- Use compatible length/time units; no universal scheme choice, stability or mesh adequacy is established by this number alone.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Analyze the full numerical or stochastic method, its support and error behavior before treating a local factor as a reliability guarantee.
References
Similar or alternative tools
- Mesh Refinement Ratio CFL Scaling
Scale a time step under a supplied refinement law.
- Heat Stencil Negative Weight Flag
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