Walther Viscosity–Temperature Equation
Predict viscosity at any temperature given two reference viscosities using the ASTM D341 (Walther) relation.
Viscosity at target T
67.9cSt
Formula, assumptions, and limits
T in kelvin. ASTM D341 chart paper prints the double-log scale so that viscosity-temperature is a straight line. Used for HFO heating-system sizing: target 12 cSt at the injector.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Viscosity | cSt | ASTM D445 / D7042 | |
| Temperature | K | input | |
| Fuel-specific constants | - | derived from two data points |