Online Flow Rate Calculator

Pipe Diameter (m):

Flow Velocity (m/s):

function calculateFlowRate() { var diameter = parseFloat(document.getElementById("pipeDiameter").value); var velocity = parseFloat(document.getElementById("flowVelocity").value); var resultDiv = document.getElementById("result"); resultDiv.innerHTML = ""; // Clear previous results if (isNaN(diameter) || isNaN(velocity) || diameter <= 0 || velocity < 0) { resultDiv.innerHTML = "Please enter valid positive numbers for pipe diameter and flow velocity."; return; } // Calculate the cross-sectional area of the pipe // Area = π * (radius)^2 // Radius = Diameter / 2 var radius = diameter / 2; var area = Math.PI * Math.pow(radius, 2); // Calculate the flow rate // Flow Rate (Q) = Area (A) * Velocity (v) var flowRate = area * velocity; resultDiv.innerHTML = "Pipe Cross-sectional Area: " + area.toFixed(4) + " m²" + "Calculated Flow Rate: " + flowRate.toFixed(4) + " m³/s"; }

Understanding Flow Rate

The flow rate, often denoted by 'Q', is a fundamental concept in fluid dynamics. It quantifies the volume of fluid that passes through a given cross-sectional area per unit of time. This is crucial in various engineering and scientific applications, from designing water distribution systems and calculating the capacity of pipelines to understanding blood flow in biological systems.

How the Flow Rate Calculator Works

Our online flow rate calculator simplifies the calculation of volumetric flow rate using two key parameters:

Pipe Diameter (m): This is the internal diameter of the pipe through which the fluid is flowing. It is measured in meters. The diameter is essential for determining the cross-sectional area of the pipe.
Flow Velocity (m/s): This represents the average speed at which the fluid is moving through the pipe. It is measured in meters per second.

The Underlying Formula

The calculation is based on a straightforward principle:

Calculate the Cross-sectional Area (A): The area of a circle (representing the pipe's cross-section) is calculated using the formula \( A = \pi r^2 \), where \( r \) is the radius of the pipe. Since the input is diameter (\( d \)), the radius is \( r = d/2 \). Thus, \( A = \pi (d/2)^2 \).
Calculate the Flow Rate (Q): The volumetric flow rate is then found by multiplying the cross-sectional area by the flow velocity: \( Q = A \times v \).

The resulting flow rate is expressed in cubic meters per second (m³/s).

Example Calculation

Let's say we have a pipe with an internal diameter of 0.2 meters and the fluid is flowing through it at an average velocity of 1.5 meters per second.

Pipe Diameter = 0.2 m
Flow Velocity = 1.5 m/s

First, we find the radius: Radius = 0.2 m / 2 = 0.1 m.

Next, we calculate the cross-sectional area: Area = \( \pi \times (0.1 \text{ m})^2 = \pi \times 0.01 \text{ m}^2 \approx 0.0314 \text{ m}^2 \).

Finally, we calculate the flow rate: Flow Rate = Area \( \times \) Velocity = \( 0.0314 \text{ m}^2 \times 1.5 \text{ m/s} \approx 0.0471 \text{ m}^3/\text{s} \).

Therefore, the flow rate in this scenario is approximately 0.0471 cubic meters per second.

Applications

Understanding and calculating flow rate is vital in numerous fields:

Civil Engineering: Designing water supply networks, sewage systems, and storm drainage.
Mechanical Engineering: Analyzing fluid power systems, cooling systems, and pump capacities.
Environmental Science: Monitoring river discharge, pollutant dispersion, and water treatment processes.
Chemical Engineering: Controlling reaction rates and material transport in industrial processes.