Calculates the Leidenfrost temperature above which a liquid droplet levitates on its own vapour film and heat transfer drops dramatically. Water's Leidenfrost point ≈ 180–220 °C — below this, droplets boil violently; above it, they bead and glide for seconds. The effect is used in spray cooling optimisation.
Inputs
T Surface C
Thermal state of the substance. Check whether the formula needs Celsius, Fahrenheit, or Kelvin (K = °C + 273.15).
T Sat C
Thermal state of the substance. Check whether the formula needs Celsius, Fahrenheit, or Kelvin (K = °C + 273.15).
G Ms2
Reference formula or conversion factor shown for context.
K Vapor W Mk
How easily heat flows through the material (W/m·K). Metals are high; insulation materials are very low.
Rho Vapor Kgm3
Mass per unit volume (kg/m³). Water: 1,000. Air: 1.225. Steel: 7,850. Affects buoyancy, flow, and structural loads.
H Fg Kj Kg
Reference formula or conversion factor shown for context.
Results
film boiling heat transfer coefficient h (W/m²·K)
Thermal energy moving from hot to cold. Rate depends on temperature difference, conductivity, and geometry (Fourier's Law for conduction; Newton's Law of Cooling for convection).
heat flux q
The value at the specified point or condition.
surface superheat ΔT (K)
The value at the specified point or condition.
h = 0.62·[ρv(ρl−ρv)g·kv³·hfg/(μv·ΔT)]^0.25
Voltage in kilovolts (kV). 1 kV = 1,000 V. Used for high-voltage transmission lines and industrial equipment.
Leidenfrost temperature
The value at the specified point or condition.
boiling regime
The operating regime — the mode or zone in which the system is currently operating.