FormulaDen.com

Physics Chemistry Math Chemical Engineering Civil Electrical Electronics Electronics and Instrumentation Materials Science Mechanical Production Engineering Financial Health

Emissivity Formula

GoEmissivity given Reference Temperature Formula

Fx Copy

LaTeX Copy

Emissivity is the ability of an object to emit infrared energy. Emissivity can have a value from 0 (shiny mirror) to 1.0 (blackbody). Most organic or oxidized surfaces have emissivity close to 0.95. Check FAQs

ε = \sqrt{\frac{μ viscosity}{ρ ∞ \cdot V ∞ \cdot r nose}}

ε - Emissivity?μ_viscosity - Dynamic Viscosity?ρ_∞ - Freestream Density?V_∞ - Freestream Velocity?r_nose - Radius of Nose?

Emissivity Example

With values

With units

Only example

Here is how the Emissivity equation looks like with Values.

Here is how the Emissivity equation looks like with Units.

Here is how the Emissivity equation looks like.

0.9489 = \sqrt{\frac{351}{1.17 \cdot 68 \cdot 0.49}}

0.9489 = \sqrt{\frac{351P}{1.17kg/m³ \cdot 68m/s \cdot 0.49m}}

0.9489 = \sqrt{\frac{351}{1.17 \cdot 68 \cdot 0.49}}

Tip: Use pencil ( Pencil

) icon above to edit Input Values and Units.

Calculate

Recalculate

Solution

Copy

Reset

You are here -

Home » Category

Engineering » Category

Mechanical » Category

Fluid Mechanics » fx Emissivity

Emissivity Solution

Follow our step by step solution on how to calculate Emissivity?

FIRST Step Consider the formula

ε = \sqrt{\frac{μ viscosity}{ρ ∞ \cdot V ∞ \cdot r nose}}

Next Step Substitute values of Variables

∴

ε = \sqrt{\frac{351P}{1.17kg/m³ \cdot 68m/s \cdot 0.49m}}

Next Step Convert Units

∴

ε = \sqrt{\frac{35.1Pa*s}{1.17kg/m³ \cdot 68m/s \cdot 0.49m}}

Next Step Prepare to Evaluate

∴

ε = \sqrt{\frac{35.1}{1.17 \cdot 68 \cdot 0.49}}

Next Step Evaluate

∴

ε = 0.948873091650102

LAST Step Rounding Answer

∴

ε = 0.9489

Emissivity Formula Elements

Variables

Functions

Emissivity

Emissivity is the ability of an object to emit infrared energy. Emissivity can have a value from 0 (shiny mirror) to 1.0 (blackbody). Most organic or oxidized surfaces have emissivity close to 0.95.

Symbol: ε

Measurement: NAUnit: Unitless

Note: Value should be between 0 to 1.

Formulas to find Emissivity

Dynamic Viscosity

The Dynamic Viscosity of a fluid is the measure of its resistance to flow when an external force is applied.

Symbol: μ_viscosity

Measurement: Dynamic ViscosityUnit: P

Note: Value should be greater than 0.

Formulas to find Dynamic Viscosity

Freestream Density

Freestream Density is the mass per unit volume of air far upstream of an aerodynamic body at a given altitude.

Symbol: ρ_∞

Measurement: DensityUnit: kg/m³

Note: Value can be positive or negative.

Formulas to find Freestream Density

Freestream Velocity

The Freestream Velocity is the velocity of air far upstream of an aerodynamic body, that is before the body has a chance to deflect, slow down or compress the air.

Symbol: V_∞

Measurement: SpeedUnit: m/s

Note: Value can be positive or negative.

Formulas to find Freestream Velocity

Radius of Nose

Radius of Nose is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length.

Symbol: r_nose

Measurement: LengthUnit: m

Note: Value should be greater than 0.

Formulas to find Radius of Nose

sqrt

A square root function is a function that takes a non-negative number as an input and returns the square root of the given input number.

Syntax: sqrt(Number)

Other Formulas to find Emissivity

Go Emissivity given Reference Temperature

ε = \sqrt{\frac{μ viscosity}{ρ ∞ \cdot \sqrt{T ref} \cdot r nose}}

How to Evaluate Emissivity?

Emissivity evaluator uses Emissivity = sqrt(Dynamic Viscosity/(Freestream Density*Freestream Velocity*Radius of Nose)) to evaluate the Emissivity, The Emissivity formula is defined as the dynamic viscosity of the fluid divided by the product of freestream density, freestream velocity, and the universal gas constant. Emissivity is denoted by ε symbol.

How to evaluate Emissivity using this online evaluator? To use this online evaluator for Emissivity, enter Dynamic Viscosity (μ_viscosity), Freestream Density (ρ_∞), Freestream Velocity (V_∞) & Radius of Nose (r_nose) and hit the calculate button.

FAQs on Emissivity

What is the formula to find Emissivity?

The formula of Emissivity is expressed as Emissivity = sqrt(Dynamic Viscosity/(Freestream Density*Freestream Velocity*Radius of Nose)). Here is an example- 0.948873 = sqrt(35.1/(1.17*68*0.49)).

How to calculate Emissivity?

With Dynamic Viscosity (μ_viscosity), Freestream Density (ρ_∞), Freestream Velocity (V_∞) & Radius of Nose (r_nose) we can find Emissivity using the formula - Emissivity = sqrt(Dynamic Viscosity/(Freestream Density*Freestream Velocity*Radius of Nose)). This formula also uses Square Root (sqrt) function(s).

What are the other ways to Calculate Emissivity?

Here are the different ways to Calculate Emissivity-

Emissivity=sqrt(Dynamic Viscosity/(Freestream Density*sqrt(Reference Temperature)*Radius of Nose))

Let Others Know

✖

Facebook

Twitter

Copied!

: Value
: Unit