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Nusselt number for gases and liquids Formula

GoNusselt number Formula

GoNusselt number for gases Formula

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The Nusselt Number is the ratio of convective to conductive heat transfer at a boundary in a fluid. Convection includes both advection and diffusion. Check FAQs

Nu = 2 + (0.4 \cdot ({Re}^{0.5}) + 0.06 \cdot ({Re}^{0.67})) \cdot ({Pr}^{0.4}) \cdot {(\frac{μ ∞}{μ w})}^{0.25}

Nu - Nusselt Number?Re - Reynolds Number?Pr - Prandtl Number?μ_∞ - Dynamic Viscosity at Free Stream Temperature?μ_w - Dynamic Viscosity at Wall Temperature?

Nusselt number for gases and liquids Example

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Here is how the Nusselt number for gases and liquids equation looks like with Values.

Here is how the Nusselt number for gases and liquids equation looks like with Units.

Here is how the Nusselt number for gases and liquids equation looks like.

40.3831 = 2 + (0.4 \cdot (5000^{0.5}) + 0.06 \cdot (5000^{0.67})) \cdot ({0.7}^{0.4}) \cdot {(\frac{0.0015}{0.0018})}^{0.25}

40.3831 = 2 + (0.4 \cdot (5000^{0.5}) + 0.06 \cdot (5000^{0.67})) \cdot ({0.7}^{0.4}) \cdot {(\frac{0.0015}{0.0018})}^{0.25}

40.3831 = 2 + (0.4 \cdot (5000^{0.5}) + 0.06 \cdot (5000^{0.67})) \cdot ({0.7}^{0.4}) \cdot {(\frac{0.0015}{0.0018})}^{0.25}

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Nusselt number for gases and liquids Solution

Follow our step by step solution on how to calculate Nusselt number for gases and liquids?

FIRST Step Consider the formula

Nu = 2 + (0.4 \cdot ({Re}^{0.5}) + 0.06 \cdot ({Re}^{0.67})) \cdot ({Pr}^{0.4}) \cdot {(\frac{μ ∞}{μ w})}^{0.25}

Next Step Substitute values of Variables

∴

Nu = 2 + (0.4 \cdot (5000^{0.5}) + 0.06 \cdot (5000^{0.67})) \cdot ({0.7}^{0.4}) \cdot {(\frac{0.0015}{0.0018})}^{0.25}

Next Step Prepare to Evaluate

∴

Nu = 2 + (0.4 \cdot (5000^{0.5}) + 0.06 \cdot (5000^{0.67})) \cdot ({0.7}^{0.4}) \cdot {(\frac{0.0015}{0.0018})}^{0.25}

Next Step Evaluate

∴

Nu = 40.3830947187982

LAST Step Rounding Answer

∴

Nu = 40.3831

Nusselt number for gases and liquids Formula Elements

Variables

Nusselt Number

The Nusselt Number is the ratio of convective to conductive heat transfer at a boundary in a fluid. Convection includes both advection and diffusion.

Symbol: Nu

Measurement: NAUnit: Unitless

Note: Value should be greater than 0.

Formulas to find Nusselt Number

Reynolds Number

The Reynolds number is the ratio of inertial forces to viscous forces within a fluid which is subjected to relative internal movement due to different fluid velocities. A region where these forces change behavior is known as a boundary layer, such as the bounding surface in the interior of a pipe.

Symbol: Re

Measurement: NAUnit: Unitless

Note: Value should be greater than 0.

Formulas to find Reynolds Number

Prandtl Number

The Prandtl number (Pr) or Prandtl group is a dimensionless number, named after the German physicist Ludwig Prandtl, defined as the ratio of momentum diffusivity to thermal diffusivity.

Symbol: Pr

Measurement: NAUnit: Unitless

Note: Value should be greater than 0.

Formulas to find Prandtl Number

Dynamic Viscosity at Free Stream Temperature

Dynamic Viscosity at Free Stream Temperature is the resisting force offered by the adjacent layers of the fluid flowing with freestream velocity.

Symbol: μ_∞

Measurement: NAUnit: Unitless

Note: Value should be greater than 0.

Formulas to find Dynamic Viscosity at Free Stream Temperature

Dynamic Viscosity at Wall Temperature

Dynamic Viscosity at Wall Temperature is the external force offered by the fluid to the wall of the object at the temperature of its surface.

Symbol: μ_w

Measurement: NAUnit: Unitless

Note: Value can be positive or negative.

Formulas to find Dynamic Viscosity at Wall Temperature

Other Formulas to find Nusselt Number

Go Nusselt number

Nu = 0.37 \cdot {Re}^{0.6}

Go Nusselt number for gases

Nu = 2 + {(0.25 \cdot Re + (3 \cdot 10^{- 4}) \cdot ({Re}^{1.6}))}^{0.5}

Go Nusselt number for air

Nu = 430 + ((5 \cdot (10^{- 3})) \cdot (Re)) + ((0.025 \cdot (10^{- 9})) \cdot ({Re}^{2})) - ((3.1 \cdot (10^{- 17})) \cdot ({Re}^{3}))

Go Nusselt number for liquids for external flow

Nu = \frac{0.97 + 0.68 \cdot ({Re}^{0.5})}{{Pr}^{- 0.3}}

How to Evaluate Nusselt number for gases and liquids?

Nusselt number for gases and liquids evaluator uses Nusselt Number = 2+(0.4*(Reynolds Number^0.5)+0.06*(Reynolds Number^0.67))*(Prandtl Number^0.4)*(Dynamic Viscosity at Free Stream Temperature/Dynamic Viscosity at Wall Temperature)^0.25 to evaluate the Nusselt Number, The Nusselt number for gases and liquids formula is defined as the ratio of convective to conductive heat transfer across a boundary. 3.5 < Re < 8*10^4. Nusselt Number is denoted by Nu symbol.

How to evaluate Nusselt number for gases and liquids using this online evaluator? To use this online evaluator for Nusselt number for gases and liquids, enter Reynolds Number (Re), Prandtl Number (Pr), Dynamic Viscosity at Free Stream Temperature (μ_∞) & Dynamic Viscosity at Wall Temperature (μ_w) and hit the calculate button.

FAQs on Nusselt number for gases and liquids

What is the formula to find Nusselt number for gases and liquids?

The formula of Nusselt number for gases and liquids is expressed as Nusselt Number = 2+(0.4*(Reynolds Number^0.5)+0.06*(Reynolds Number^0.67))*(Prandtl Number^0.4)*(Dynamic Viscosity at Free Stream Temperature/Dynamic Viscosity at Wall Temperature)^0.25. Here is an example- 40.38309 = 2+(0.4*(5000^0.5)+0.06*(5000^0.67))*(0.7^0.4)*(0.0015/0.0018)^0.25.

How to calculate Nusselt number for gases and liquids?

With Reynolds Number (Re), Prandtl Number (Pr), Dynamic Viscosity at Free Stream Temperature (μ_∞) & Dynamic Viscosity at Wall Temperature (μ_w) we can find Nusselt number for gases and liquids using the formula - Nusselt Number = 2+(0.4*(Reynolds Number^0.5)+0.06*(Reynolds Number^0.67))*(Prandtl Number^0.4)*(Dynamic Viscosity at Free Stream Temperature/Dynamic Viscosity at Wall Temperature)^0.25.

What are the other ways to Calculate Nusselt Number?

Here are the different ways to Calculate Nusselt Number-

Nusselt Number=0.37*Reynolds Number^0.6
Nusselt Number=2+(0.25*Reynolds Number+(3*10^-4)*(Reynolds Number^1.6))^0.5
Nusselt Number=430+((5*(10^-3))*(Reynolds Number))+((0.025*(10^-9))*(Reynolds Number^2))-((3.1*(10^-17))*(Reynolds Number^3))

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Nusselt number for gases and liquids Formula

​GoNusselt number Formula

​GoNusselt number for gases Formula

Nusselt number for gases and liquids Example

Nusselt number for gases and liquids Solution

Nusselt number for gases and liquids Formula Elements

Other Formulas to find Nusselt Number

How to Evaluate Nusselt number for gases and liquids?

FAQs on Nusselt number for gases and liquids

Variable Name

GoNusselt number Formula

GoNusselt number for gases Formula