Petroffs Equation for Coefficient of Friction Calculator

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Vertical Shaft Rotating in Guide Bearing

✖The Dynamic Viscosity of a fluid is the measure of its resistance to flow when an external force is applied.ⓘ Dynamic Viscosity [μ_viscosity]			+10% -10%
✖The Shaft Speed is the speed of rotation of the Shaft.ⓘ Shaft Speed [N]			+10% -10%
✖Load per Projected Area of Bearing is defined as the load that is acting on the projected area of the bearing which is the product of Axial length of bearing and Journal diameter.ⓘ Load per Projected Area of Bearing [P]			+10% -10%
✖Diametrical Clearance Ratio or Relative Clearance is the ratio of diametrical clearance to the diameter of journal.ⓘ Diametrical Clearance Ratio or Relative Clearance [ψ]			+10% -10%

✖The Coefficient of Friction (μ) is the ratio defining the force that resists the motion of one body in relation to another body in contact with it.ⓘ Petroffs Equation for Coefficient of Friction [μ_friction]

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Formula

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Petroffs Equation for Coefficient of Friction

Formula

`"μ"_{"friction"} = 2*pi^2*"μ"_{"viscosity"}*("N"/"P")*(1/"ψ")`

Example

`"0.268453"=2*pi^2*"10.2P"*("10rev/s"/"0.15MPa")*(1/"0.005")`

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Petroffs Equation for Coefficient of Friction Solution

STEP 0: Pre-Calculation Summary

Formula Used

Coefficient of Friction = 2*pi^2*Dynamic Viscosity*(Shaft Speed/Load per Projected Area of Bearing)*(1/Diametrical Clearance Ratio or Relative Clearance)
μ_friction = 2*pi^2*μ_viscosity*(N/P)*(1/ψ)
This formula uses 1 Constants, 5 Variables

Constants Used

pi - Archimedes' constant Value Taken As 3.14159265358979323846264338327950288

Variables Used

Coefficient of Friction - The Coefficient of Friction (μ) is the ratio defining the force that resists the motion of one body in relation to another body in contact with it.
Dynamic Viscosity - (Measured in Pascal Second) - The Dynamic Viscosity of a fluid is the measure of its resistance to flow when an external force is applied.
Shaft Speed - (Measured in Hertz) - The Shaft Speed is the speed of rotation of the Shaft.
Load per Projected Area of Bearing - (Measured in Pascal) - Load per Projected Area of Bearing is defined as the load that is acting on the projected area of the bearing which is the product of Axial length of bearing and Journal diameter.
Diametrical Clearance Ratio or Relative Clearance - Diametrical Clearance Ratio or Relative Clearance is the ratio of diametrical clearance to the diameter of journal.

STEP 1: Convert Input(s) to Base Unit

Dynamic Viscosity: 10.2 Poise --> 1.02 Pascal Second (Check conversion here)
Shaft Speed: 10 Revolution per Second --> 10 Hertz (Check conversion here)
Load per Projected Area of Bearing: 0.15 Megapascal --> 150000 Pascal (Check conversion here)
Diametrical Clearance Ratio or Relative Clearance: 0.005 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

μ_friction = 2*pi^2*μ_viscosity*(N/P)*(1/ψ) --> 2*pi^2*1.02*(10/150000)*(1/0.005)

Evaluating ... ...

μ_friction = 0.268453239709631

STEP 3: Convert Result to Output's Unit

0.268453239709631 --> No Conversion Required

FINAL ANSWER

0.268453239709631 ≈ 0.268453 <-- Coefficient of Friction

(Calculation completed in 00.007 seconds)

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Petroffs Equation for Coefficient of Friction

Go Coefficient of Friction = 2*pi^2*Dynamic Viscosity*(Shaft Speed/Load per Projected Area of Bearing)*(1/Diametrical Clearance Ratio or Relative Clearance)

Absolute Viscosity from Petroff's Equation

Go Dynamic Viscosity = (Coefficient of Friction*Diametrical Clearance Ratio or Relative Clearance)/(2*pi^2*(Shaft Speed/Load per Projected Area of Bearing))

Diametrical Clearance Ratio or Relative Clearance from Petroff's Equaiton

Go Diametrical Clearance Ratio or Relative Clearance = 2*pi^2*(Dynamic Viscosity/Coefficient of Friction)*(Shaft Speed/Load per Projected Area of Bearing)

Load per Projected Area of Bearing from Petroff's Equation

Go Load per Projected Area of Bearing = 2*pi^2*(Dynamic Viscosity/Coefficient of Friction)*(Shaft Speed/Diametrical Clearance Ratio or Relative Clearance)

Petroffs Equation for Coefficient of Friction Formula

What is petroff's equation?

Petroff's equation gives the coefficient of friction in journal bearings. It is based on the following assumptions.
-It assumes that the shaft (journal) and the bearing are concentric.
-The bearing is subjected to light load.

What is the significance of petroff's equation?

Petroff's equation indicates that there are two important dimensionless parameters (r/c) and (µn/P) that govern the coefficient of friction and other friction properties like frictional torque, frictional power loss and temperature rise in the bearing.

How to Calculate Petroffs Equation for Coefficient of Friction?

Petroffs Equation for Coefficient of Friction calculator uses Coefficient of Friction = 2*pi^2*Dynamic Viscosity*(Shaft Speed/Load per Projected Area of Bearing)*(1/Diametrical Clearance Ratio or Relative Clearance) to calculate the Coefficient of Friction, The Petroffs equation for coefficient of friction formula provides estimation of coefficient of friction in sliding bearing. Coefficient of Friction is denoted by μ_friction symbol.

How to calculate Petroffs Equation for Coefficient of Friction using this online calculator? To use this online calculator for Petroffs Equation for Coefficient of Friction, enter Dynamic Viscosity (μ_viscosity), Shaft Speed (N), Load per Projected Area of Bearing (P) & Diametrical Clearance Ratio or Relative Clearance (ψ) and hit the calculate button. Here is how the Petroffs Equation for Coefficient of Friction calculation can be explained with given input values -> 0.268453 = 2*pi^2*1.02*(10/150000)*(1/0.005).

FAQ

What is Petroffs Equation for Coefficient of Friction?

The Petroffs equation for coefficient of friction formula provides estimation of coefficient of friction in sliding bearing and is represented as μ_friction = 2*pi^2*μ_viscosity*(N/P)*(1/ψ) or Coefficient of Friction = 2*pi^2*Dynamic Viscosity*(Shaft Speed/Load per Projected Area of Bearing)*(1/Diametrical Clearance Ratio or Relative Clearance). The Dynamic Viscosity of a fluid is the measure of its resistance to flow when an external force is applied, The Shaft Speed is the speed of rotation of the Shaft, Load per Projected Area of Bearing is defined as the load that is acting on the projected area of the bearing which is the product of Axial length of bearing and Journal diameter & Diametrical Clearance Ratio or Relative Clearance is the ratio of diametrical clearance to the diameter of journal.

How to calculate Petroffs Equation for Coefficient of Friction?

The Petroffs equation for coefficient of friction formula provides estimation of coefficient of friction in sliding bearing is calculated using Coefficient of Friction = 2*pi^2*Dynamic Viscosity*(Shaft Speed/Load per Projected Area of Bearing)*(1/Diametrical Clearance Ratio or Relative Clearance). To calculate Petroffs Equation for Coefficient of Friction, you need Dynamic Viscosity (μ_viscosity), Shaft Speed (N), Load per Projected Area of Bearing (P) & Diametrical Clearance Ratio or Relative Clearance (ψ). With our tool, you need to enter the respective value for Dynamic Viscosity, Shaft Speed, Load per Projected Area of Bearing & Diametrical Clearance Ratio or Relative Clearance and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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