Calculate Flow Rate Based on Pressure and Pipe Size
by
Fluid Flow Rate Calculator
This calculator helps you estimate the flow rate of a fluid through a pipe based on the pressure difference across the pipe and the pipe's dimensions. This is a simplified model and does not account for all real-world factors like viscosity, fluid density, pipe roughness, or turbulence. For precise calculations, consult with fluid dynamics engineers.
.calculator-container {
font-family: Arial, sans-serif;
border: 1px solid #ccc;
padding: 20px;
border-radius: 8px;
max-width: 600px;
margin: 20px auto;
background-color: #f9f9f9;
}
.calculator-inputs {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
gap: 15px;
margin-bottom: 20px;
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
margin-bottom: 5px;
font-weight: bold;
color: #333;
}
.input-group input {
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
}
button {
background-color: #4CAF50;
color: white;
padding: 12px 20px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
margin-bottom: 20px;
}
button:hover {
background-color: #45a049;
}
#result {
margin-top: 20px;
padding: 15px;
border: 1px dashed #ddd;
border-radius: 4px;
background-color: #fff;
min-height: 50px;
font-size: 1.1em;
color: #555;
}
function calculateFlowRate() {
var pressureDrop = parseFloat(document.getElementById("pressureDrop").value);
var pipeDiameter = parseFloat(document.getElementById("pipeDiameter").value);
var pipeLength = parseFloat(document.getElementById("pipeLength").value);
var fluidViscosity = parseFloat(document.getElementById("fluidViscosity").value);
var fluidDensity = parseFloat(document.getElementById("fluidDensity").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous result
if (isNaN(pressureDrop) || isNaN(pipeDiameter) || isNaN(pipeLength) || isNaN(fluidViscosity) || isNaN(fluidDensity) ||
pressureDrop < 0 || pipeDiameter <= 0 || pipeLength <= 0 || fluidViscosity <= 0 || fluidDensity <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
// Constants for unit conversion
var psiToPa = 6894.76; // Pascals per psi
var inchesToMeters = 0.0254; // Meters per inch
var feetToMeters = 0.3048; // Meters per foot
var cPToPaS = 0.001; // Pascal-seconds per centipoise
var lbPerFt3ToKgPerM3 = 16.0185; // kg/m³ per lb/ft³
var litersPerMinutePerCubicMetersPerSecond = 60000; // L/min per m³/s
// Convert inputs to SI units for calculation
var pressureDropSI = pressureDrop * psiToPa;
var pipeDiameterSI = pipeDiameter * inchesToMeters;
var pipeLengthSI = pipeLength * feetToMeters;
var fluidViscositySI = fluidViscosity * cPToPaS;
var fluidDensitySI = fluidDensity * lbPerFt3ToKgPerM3;
// Calculate pipe cross-sectional area in m²
var pipeRadiusSI = pipeDiameterSI / 2;
var pipeAreaSI = Math.PI * Math.pow(pipeRadiusSI, 2);
// Simplified Hagen-Poiseuille equation for laminar flow, assuming relatively low Reynolds number
// Q = (π * ΔP * D⁴) / (128 * μ * L)
// This formula is for laminar flow and might not be accurate for turbulent flow.
// A more complex calculation involving the Reynolds number and friction factor would be needed for accuracy across flow regimes.
// For simplicity, we'll use this for estimation.
var flowRateSI = (Math.PI * pressureDropSI * Math.pow(pipeDiameterSI, 4)) / (128 * fluidViscositySI * pipeLengthSI);
// Convert flow rate from m³/s to Liters per Minute (LPM)
var flowRateLPM = flowRateSI * litersPerMinutePerCubicMetersPerSecond;
// Display the result
resultDiv.innerHTML = "Estimated Flow Rate: " + flowRateLPM.toFixed(2) + " LPM";
}