Description
Multiply positive pitch by positive revolutionsPerSecond for idealAdvanceSpeed, then return 1 - advanceSpeed / idealAdvanceSpeed as slipFraction.
Marine speed, thrust, and propeller ratios depend on a declared reference frame and coherent units. A scalar term usually describes only one part of vessel performance.
Multiply positive pitch by positive revolutionsPerSecond for idealAdvanceSpeed, then return 1 - advanceSpeed / idealAdvanceSpeed as slipFraction.
When to use this tool
Use Propeller Slip Measured Advance Term when you need one explicit marine performance ratio or residual.
How to use the tool and how it works
- Enter pitch, revolutionsPerSecond, advanceSpeed. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read idealAdvanceSpeed, slipFraction. Use the output convention below.
Multiply positive pitch by positive revolutionsPerSecond for idealAdvanceSpeed, then return 1 - advanceSpeed / idealAdvanceSpeed as slipFraction.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| pitch | Pitch | Required. Finite number; strictly above 0. |
| revolutionsPerSecond | Rotational frequency in revolutions per second, not RPM. | Required. Finite number; strictly above 0. |
| advanceSpeed | Advance Speed | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| idealAdvanceSpeed | Ideal Advance Speed | Required. Finite number. |
| slipFraction | Slip Fraction | Required. Finite number. |
{
"input": {
"pitch": 2,
"revolutionsPerSecond": 5,
"advanceSpeed": 8
},
"output": {
"idealAdvanceSpeed": 10,
"slipFraction": 0.19999999999999996
}
}Limitations and assumptions
- Pitch and advance speed must use compatible length units per second; the fraction is not constrained to [0, 1].
- 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
Use measured operating data and a vessel-specific propulsion model for performance predictions.
References
Similar or alternative tools
- Propeller Advance Coefficient Reference
Divide advanceSpeed by positive revolutionsPerSecond times positive diameter for advanceCoefficient.
- Wake Fraction Water Inflow Term
Divide nonnegative inflowSpeed by positive shipSpeed and subtract the quotient from one.