Hydraulic Equivalence Settling Velocity
Invert measured fossil settling speed to a Stokes-equivalent reference sediment diameter and applicability Reynolds screen; unlike existing forward Stokes particle settling, the target is equivalent grain size, with non-creeping estimates flagged.
Description
Hydraulic equivalence assigns a reference grain the same settling speed as an observed fossil.
Hydraulic equivalence assigns a reference grain the same settling speed as an observed fossil. Stokes inversion assumes creeping flow.
Invert measured fossil settling speed to a Stokes-equivalent reference sediment diameter and applicability Reynolds screen; unlike existing forward Stokes particle settling, the target is equivalent grain size, with non-creeping estimates flagged.
When to use Hydraulic Equivalence Settling Velocity
Use this tool to invert measured fossil settling speed to a Stokes-equivalent reference sediment diameter and applicability Reynolds screen; unlike existing forward Stokes particle settling, the target is equivalent grain size, with non-creeping estimates flagged.
Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
How to use Hydraulic Equivalence Settling Velocity and understand its results
- Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
- Enter observedFossilSettlingSpeedMPerSecond, waterDensityKgPerM3, referenceSedimentDensityKgPerM3, waterDynamicViscosityPaSeconds, gravityMPerSecondSquared, callerMaximumStokesReynoldsNumber using the field table and calculation rules, then run the tool.
- Read hydraulicallyEquivalentSedimentDiameterM, equivalentSedimentReynoldsNumber, withinCallerCreepingFlowScreen. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedFossilSettlingSpeedMPerSecond | Observed fossil settling speed m per second | number | Required |
| waterDensityKgPerM3 | Water density kg per m3 | number | Required |
| referenceSedimentDensityKgPerM3 | Reference sediment density kg per m3 | number | Required |
| waterDynamicViscosityPaSeconds | Water dynamic viscosity Pa seconds | number | Required |
| gravityMPerSecondSquared | Gravity m per second squared | number | Required |
| callerMaximumStokesReynoldsNumber | Caller maximum stokes reynolds number | number | Required |
Use positive speed, viscosity, gravity and densities with sediment denser than water. Compute equivalent diameter and Reynolds number, then compare it inclusively with a positive caller maximum.1
diameter = sqrt(18 × viscosity × observed speed/[(sediment density−water density) × gravity]) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| hydraulicallyEquivalentSedimentDiameterM | Hydraulically equivalent sediment diameter m | number |
| equivalentSedimentReynoldsNumber | Equivalent sediment reynolds number | number |
| withinCallerCreepingFlowScreen | Within caller creeping flow screen | boolean |
{
"input": {
"observedFossilSettlingSpeedMPerSecond": 0.01,
"waterDensityKgPerM3": 1000,
"referenceSedimentDensityKgPerM3": 2000,
"waterDynamicViscosityPaSeconds": 0.001,
"gravityMPerSecondSquared": 10,
"callerMaximumStokesReynoldsNumber": 1
},
"output": {
"hydraulicallyEquivalentSedimentDiameterM": 0.00013416407864998739,
"equivalentSedimentReynoldsNumber": 1.3416407864998736,
"withinCallerCreepingFlowScreen": false
}
}Limitations and assumptions
Noncreeping estimates are flagged, not corrected; the fossil's shape is not solved.
Numbers and computed results must be finite; overflow produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Clast Terminal Velocity Lithic: Balance spherical-clast buoyant weight against caller constant quadratic drag and report Reynolds number for applicability review; not a Stokes viscous law, nonspherical drag solver or hazard trajectory. For a complementary task, use Alexander Footprint Speed Estimator: Evaluate Alexander’s published footprint-stride speed approximation with explicit estimated hip height; stride is successive same-foot spacing, not step length, and model does not prove gait or actual speed.
References
-
Hydraulic Equivalence Settling Velocity — tool.io
Similar or alternative tools
- Clast Terminal Velocity Lithic
Balance spherical-clast buoyant weight against caller constant quadratic drag and report Reynolds number for applicability review; not a Stokes viscous law, nonspherical drag solver or hazard trajectory.
- Alexander Footprint Speed Estimator
Evaluate Alexander’s published footprint-stride speed approximation with explicit estimated hip height; stride is successive same-foot spacing, not step length, and model does not prove gait or actual speed.