Cavitation Index Calculator

Enter the values to use our Basic and advanced Cavitation Index calculator for accurate and efficient calculation. Furthermore, read the formula and solved examples for better understanding of how it works.

Formula:

The formula is:

$\text{CI} = \frac{P – P_v}{0.5 \times \rho \times V^2}$

Variables

Variable	Meaning
CI	Cavitation Index (a measure of the likelihood of cavitation)
P	Local pressure (pressure at a specific point in the fluid)
$P_v$	Vapor pressure of the fluid
$\rho$	Density of the fluid
V	Flow velocity of the fluid

How to Calculate ?

Firstly, determine the local pressure (P) in the fluid system. Secondly, identify the vapor pressure ( $P_v$ ) of the fluid at the given temperature. Thirdly, measure the density ( $\rho$ ) of the fluid. Fourthly, determine the flow velocity (V) of the fluid. Finally, subtract the vapor pressure from the local pressure, divide the result by $0.5 \times \rho \times V^2$ to calculate the Cavitation Index (CI).

Solved Examples:

Example 1:

Given:

Local Pressure ( $P$ ) = 500 kPa
Vapor Pressure ( $P_v$ ) = 3 kPa
Fluid Density ( $\r$ ) = 1000 kg/m³
Flow Velocity (V) = 10 m/s

Calculation	Instructions
Step 1: CI = $\frac{P – P_v}{0.5 \times \rho \times V^2}$	Start with the formula.
Step 2: CI = $\frac{500 – 3}{0.5 \times 1000 \times 10^2}$	Replace P with 500 kPa, $P_v$ with 3 kPa, $\rho$ with 1000 kg/m³, and V with 10 m/s.
Step 3: CI = $\frac{497}{0.5 \times 1000 \times 100}$	Subtract the vapor pressure from the local pressure.
Step 4: CI = $\frac{497}{50000}$	Multiply $0.5 \times 1000 \times 100$ get 50000.
Step 5: CI = 0.00994	Divide 497 by 50000 to get the Cavitation Index.

Answer:
The Cavitation Index is 0.00994.

Example 2:

Given:

Local Pressure ( $P$ ) = 800 kPa
Vapor Pressure ( $P_v$ ) = 5 kPa
Fluid Density ( $\$ ) = 950 kg/m³
Flow Velocity (V) = 15 m/s

Calculation	Instructions
Step 1: CI = $\frac{P – P_v}{0.5 \times \rho \times V^2}$	Start with the formula.
Step 2: CI = $\frac{800 – 5}{0.5 \times 950 \times 15^2}$	Replace P with 800 kPa, $P_v$ with 5 kPa, with 950 kg/m³, and V with 15 m/s.
Step 3: CI = $\frac{795}{0.5 \times 950 \times 225}$	Subtract the vapor pressure from the local pressure.
Step 4: CI = $\frac{795}{106875}$	Multiply $0.5 \times 950 \times 225$ to get 106875.
Step 5: CI = 0.00744	Divide 795 by 106875 to get the Cavitation Index.

Answer:
The Cavitation Index is 0.00744.

What is the Cavitation Index Calculator?

The Cavitation Index Calculator helps in assessing the possibility of cavitation that occur in a fluid system. Cavitation is a phenomenon where vapor bubbles form in a fluid due to low pressure and then collapse, potentially causing damage to equipment like pumps, propellers, and turbines.

It is calculated using the formula $\text{CI} = \frac{P – P_v}{0.5 \times \rho \times V^2}$ , where P is the local pressure, $P_v$ is the vapor pressure, $\rho$ is the fluid density, and V is the flow velocity. A lower Cavitation Index indicates a higher risk of cavitation.

Final Words:

An accurate cavitation index is indeed crucial for engineers in a way to help them design efficient systems that are able to minimize the risk of cavitation. In that way, it ensures the longevity and efficient functionality of fluid handling tools.

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1 Cavitation Index Calculator