This calculator helps estimate the rate at which water will evaporate from a heated surface under specific conditions. Understanding evaporation rates is crucial in various industrial processes, such as drying, sterilization, and chemical engineering. The calculation is based on fundamental principles of heat and mass transfer.
function calculateEvaporationRate() {
var surfaceArea = parseFloat(document.getElementById("surfaceArea").value);
var heatFlux = parseFloat(document.getElementById("heatFlux").value);
var latentHeat = parseFloat(document.getElementById("latentHeat").value);
var densityOfWater = parseFloat(document.getElementById("densityOfWater").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (isNaN(surfaceArea) || isNaN(heatFlux) || isNaN(latentHeat) || isNaN(densityOfWater)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (surfaceArea <= 0 || heatFlux <= 0 || latentHeat <= 0 || densityOfWater <= 0) {
resultDiv.innerHTML = "All input values must be positive.";
return;
}
// Calculation:
// 1. Total heat transfer (Q) = Heat Flux (q) * Surface Area (A)
var totalHeatTransfer = heatFlux * surfaceArea; // Units: Watts (W)
// 2. Mass evaporated (m) = Total Heat Transfer (Q) / Latent Heat of Vaporization (Lv)
var massEvaporated = totalHeatTransfer / latentHeat; // Units: kg
// 3. Volume evaporated (V) = Mass evaporated (m) / Density of Water (ρ)
var volumeEvaporated = massEvaporated / densityOfWater; // Units: m³
// 4. Evaporation Rate (R) = Mass evaporated (m) / Time (assuming 1 second for rate per second)
// For a more practical rate, we often express it in kg/s or kg/hr.
// Let's calculate it in kg/s for now.
var evaporationRatePerSecondKg = massEvaporated; // Since time = 1 second
// To get mm/hr, we need to convert volume to depth and time to hours.
// Volume (m³) = Area (m²) * Depth (m)
// Depth (m) = Volume (m³) / Area (m²)
var depthEvaporatedMeters = volumeEvaporated / surfaceArea; // Units: meters
// Convert depth to millimeters
var depthEvaporatedMm = depthEvaporatedMeters * 1000; // Units: mm
// Convert rate from per second to per hour
var evaporationRatePerSecondMm = depthEvaporatedMm; // Since depth is calculated for 1 second of mass
var evaporationRatePerHourMm = evaporationRatePerSecondMm * 3600; // Units: mm/hr
// Let's present the primary result as mass per unit time and depth per unit time.
resultDiv.innerHTML = `
Estimated Evaporation Rate:
Mass Evaporated per Second: ${evaporationRatePerSecondKg.toFixed(6)} kg/s
Volume Evaporated per Second: ${volumeEvaporated.toFixed(9)} m³/s
Depth Evaporated per Hour: ${evaporationRatePerHourMm.toFixed(3)} mm/hr