Thoma's cavitation factor Calculator

✖The Atmospheric Pressure Head for Pump is the height of a liquid column that corresponds to the atmospheric pressure.ⓘ Atmospheric Pressure Head for Pump [H_a]			+10% -10%
✖Suction head of centrifugal pump is the vertical height of the center line of the pump shaft above the liquid surface in the sump from which the liquid is being raised.ⓘ Suction Head of Centrifugal Pump [h_s]			+10% -10%
✖The Vapour Pressure Head is the head corresponding to the vapour pressure of the liquid.ⓘ Vapour Pressure Head [H_v]			+10% -10%
✖The Manometric Head of Centrifugal Pump is the head against which the centrifugal pump has to work.ⓘ Manometric Head of Centrifugal Pump [H_m]			+10% -10%

✖Thoma's Cavitation Factor is used to indicate the onset of cavitation.ⓘ Thoma's cavitation factor [σ]

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Thoma's cavitation factor Solution

STEP 0: Pre-Calculation Summary

Formula Used

Thoma's Cavitation Factor = (Atmospheric Pressure Head for Pump-Suction Head of Centrifugal Pump-Vapour Pressure Head)/Manometric Head of Centrifugal Pump
σ = (H_a-h_s-H_v)/H_m
This formula uses 5 Variables

Variables Used

Thoma's Cavitation Factor - Thoma's Cavitation Factor is used to indicate the onset of cavitation.
Atmospheric Pressure Head for Pump - (Measured in Meter) - The Atmospheric Pressure Head for Pump is the height of a liquid column that corresponds to the atmospheric pressure.
Suction Head of Centrifugal Pump - (Measured in Meter) - Suction head of centrifugal pump is the vertical height of the center line of the pump shaft above the liquid surface in the sump from which the liquid is being raised.
Vapour Pressure Head - (Measured in Meter) - The Vapour Pressure Head is the head corresponding to the vapour pressure of the liquid.
Manometric Head of Centrifugal Pump - (Measured in Meter) - The Manometric Head of Centrifugal Pump is the head against which the centrifugal pump has to work.

STEP 1: Convert Input(s) to Base Unit

Atmospheric Pressure Head for Pump: 28.7 Meter --> 28.7 Meter No Conversion Required
Suction Head of Centrifugal Pump: 7.3 Meter --> 7.3 Meter No Conversion Required
Vapour Pressure Head: 2.2 Meter --> 2.2 Meter No Conversion Required
Manometric Head of Centrifugal Pump: 25.3 Meter --> 25.3 Meter No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

σ = (H_a-h_s-H_v)/H_m --> (28.7-7.3-2.2)/25.3

Evaluating ... ...

σ = 0.758893280632411

STEP 3: Convert Result to Output's Unit

0.758893280632411 --> No Conversion Required

FINAL ANSWER

0.758893280632411 ≈ 0.758893 <-- Thoma's Cavitation Factor

(Calculation completed in 00.004 seconds)

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Created by Sagar S Kulkarni

Dayananda Sagar College of Engineering (DSCE), Bengaluru

Sagar S Kulkarni has created this Calculator and 200+ more calculators!

Verified by Nishan Poojary

Shri Madhwa Vadiraja Institute of Technology and Management (SMVITM), Udupi

Nishan Poojary has verified this Calculator and 400+ more calculators!

< Geometric and Flow Parameters Calculators

Volume of liquid at inlet

LaTeX Go Actual Discharge at Centrifugal Pump Outlet = pi*Diameter of Centrifugal Pump Impeller at Inlet*Width of Impeller at Inlet*Flow Velocity at Inlet of Centrifugal Pump

Speed ratio

LaTeX Go Speed Ratio Centrifugal Pump = Tangential Velocity of Impeller at Outlet/sqrt(2*[g]*Manometric Head of Centrifugal Pump)

Weight of liquid

LaTeX Go Weight of Liquid in Pump = Specific Weight of Liquid*Actual Discharge at Centrifugal Pump Outlet

Static head

LaTeX Go Static Head of Centrifugal Pump = Suction Head of Centrifugal Pump+Delivery Head of Pump

Thoma's cavitation factor Formula

LaTeX Go

Thoma's Cavitation Factor = (Atmospheric Pressure Head for Pump-Suction Head of Centrifugal Pump-Vapour Pressure Head)/Manometric Head of Centrifugal Pump
σ = (H_a-h_s-H_v)/H_m

When does cavitation occur in centrifugal pumps?

Cavitation begins to appear in centrifugal pumps when the pressure at the suction falls below the vapour pressure of the liquid. Thoma’s cavitation factor is used to indicate the onset of cavitation.

How to Calculate Thoma's cavitation factor?

Thoma's cavitation factor calculator uses Thoma's Cavitation Factor = (Atmospheric Pressure Head for Pump-Suction Head of Centrifugal Pump-Vapour Pressure Head)/Manometric Head of Centrifugal Pump to calculate the Thoma's Cavitation Factor, Thoma's cavitation factor formula is defined as a dimensionless parameter that characterizes the cavitation phenomenon in centrifugal pumps, providing a measure of the pump's susceptibility to cavitation based on its geometric and flow parameters. Thoma's Cavitation Factor is denoted by σ symbol.

How to calculate Thoma's cavitation factor using this online calculator? To use this online calculator for Thoma's cavitation factor, enter Atmospheric Pressure Head for Pump (H_a), Suction Head of Centrifugal Pump (h_s), Vapour Pressure Head (H_v) & Manometric Head of Centrifugal Pump (H_m) and hit the calculate button. Here is how the Thoma's cavitation factor calculation can be explained with given input values -> 0.758893 = (28.7-7.3-2.2)/25.3.

FAQ

What is Thoma's cavitation factor?

Thoma's cavitation factor formula is defined as a dimensionless parameter that characterizes the cavitation phenomenon in centrifugal pumps, providing a measure of the pump's susceptibility to cavitation based on its geometric and flow parameters and is represented as σ = (H_a-h_s-H_v)/H_m or Thoma's Cavitation Factor = (Atmospheric Pressure Head for Pump-Suction Head of Centrifugal Pump-Vapour Pressure Head)/Manometric Head of Centrifugal Pump. The Atmospheric Pressure Head for Pump is the height of a liquid column that corresponds to the atmospheric pressure, Suction head of centrifugal pump is the vertical height of the center line of the pump shaft above the liquid surface in the sump from which the liquid is being raised, The Vapour Pressure Head is the head corresponding to the vapour pressure of the liquid & The Manometric Head of Centrifugal Pump is the head against which the centrifugal pump has to work.

How to calculate Thoma's cavitation factor?

Thoma's cavitation factor formula is defined as a dimensionless parameter that characterizes the cavitation phenomenon in centrifugal pumps, providing a measure of the pump's susceptibility to cavitation based on its geometric and flow parameters is calculated using Thoma's Cavitation Factor = (Atmospheric Pressure Head for Pump-Suction Head of Centrifugal Pump-Vapour Pressure Head)/Manometric Head of Centrifugal Pump. To calculate Thoma's cavitation factor, you need Atmospheric Pressure Head for Pump (H_a), Suction Head of Centrifugal Pump (h_s), Vapour Pressure Head (H_v) & Manometric Head of Centrifugal Pump (H_m). With our tool, you need to enter the respective value for Atmospheric Pressure Head for Pump, Suction Head of Centrifugal Pump, Vapour Pressure Head & Manometric Head of Centrifugal Pump and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Thoma's Cavitation Factor?

In this formula, Thoma's Cavitation Factor uses Atmospheric Pressure Head for Pump, Suction Head of Centrifugal Pump, Vapour Pressure Head & Manometric Head of Centrifugal Pump. We can use 1 other way(s) to calculate the same, which is/are as follows -

Thoma's Cavitation Factor = Net Positive Suction Head of Centrifugal Pump/Manometric Head of Centrifugal Pump

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