Flow Rate Calculator
This calculator helps you determine the flow rate of water through a pipe based on the cross-sectional area of the pipe and the average velocity of the water.
Understanding Flow Rate
Flow rate (often denoted by 'Q') is a fundamental concept in fluid dynamics, representing the volume of fluid that passes through a given surface per unit of time. It's commonly measured in cubic meters per second (m³/s) or liters per minute (L/min).
The formula used in this calculator is derived from the basic relationship between flow rate, cross-sectional area, and velocity:
Q = A * v
Where:
- Q is the flow rate (m³/s)
- A is the cross-sectional area of the pipe (m²)
- v is the average velocity of the water (m/s)
The cross-sectional area (A) of a circular pipe is calculated using the formula for the area of a circle:
A = π * r²
Where:
- π (pi) is a mathematical constant, approximately 3.14159
- r is the radius of the pipe (m), which is half of the diameter.
This calculator first computes the radius from the provided diameter, then calculates the cross-sectional area, and finally multiplies it by the water velocity to determine the flow rate.
function calculateFlowRate() {
var pipeDiameter = parseFloat(document.getElementById("pipeDiameter").value);
var waterVelocity = parseFloat(document.getElementById("waterVelocity").value);
var resultElement = document.getElementById("result");
resultElement.innerHTML = ""; // Clear previous results
if (isNaN(pipeDiameter) || isNaN(waterVelocity)) {
resultElement.innerHTML = "Please enter valid numbers for both diameter and velocity.";
return;
}
if (pipeDiameter <= 0 || waterVelocity <= 0) {
resultElement.innerHTML = "Diameter and velocity must be positive values.";
return;
}
// Calculate radius
var pipeRadius = pipeDiameter / 2;
// Calculate cross-sectional area
var crossSectionalArea = Math.PI * Math.pow(pipeRadius, 2);
// Calculate flow rate
var flowRate = crossSectionalArea * waterVelocity;
// Display the result
resultElement.innerHTML = "
Calculated Flow Rate:
" +
"
Cross-sectional Area: " + crossSectionalArea.toFixed(6) + " m²" +
"
Flow Rate (Q): " + flowRate.toFixed(4) + " m³/s" +
"
Flow Rate (L/min): " + (flowRate * 60 * 1000).toFixed(2) + " L/min";
}
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