Emissivity given heat transfer coefficient by radiation Solution

STEP 0: Pre-Calculation Summary
Formula Used
Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature)))
ε = hr/([Stefan-BoltZ]*((Tw^4-Ts^4)/(Tw-Ts)))
This formula uses 1 Constants, 4 Variables
Constants Used
[Stefan-BoltZ] - Stefan-Boltzmann Constant Value Taken As 5.670367E-8
Variables Used
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.
Heat Transfer Coefficient by Radiation - (Measured in Watt per Square Meter per Kelvin) - Heat Transfer Coefficient by Radiation is the heat transferred per unit area per kelvin.
Wall Temperature - (Measured in Kelvin) - Wall Temperature is the temperature at the wall.
Saturation Temperature - (Measured in Kelvin) - Saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase.
STEP 1: Convert Input(s) to Base Unit
Heat Transfer Coefficient by Radiation: 1.5 Watt per Square Meter per Kelvin --> 1.5 Watt per Square Meter per Kelvin No Conversion Required
Wall Temperature: 300 Kelvin --> 300 Kelvin No Conversion Required
Saturation Temperature: 200 Kelvin --> 200 Kelvin No Conversion Required
STEP 2: Evaluate Formula
Substituting Input Values in Formula
ε = hr/([Stefan-BoltZ]*((Tw^4-Ts^4)/(Tw-Ts))) --> 1.5/([Stefan-BoltZ]*((300^4-200^4)/(300-200)))
Evaluating ... ...
ε = 0.406974064940119
STEP 3: Convert Result to Output's Unit
0.406974064940119 --> No Conversion Required
FINAL ANSWER
0.406974064940119 0.406974 <-- Emissivity
(Calculation completed in 00.004 seconds)

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

Maximum heat flux to nucleate pool boiling
Go Heat Flux = (1.464*10^-9)*(((Specific Heat of Liquid*(Thermal Conductivity of Liquid^2)*(Density of Liquid^0.5)*(Density of Liquid-Density of Vapour))/(Density of Vapour*Change in Enthalpy of Vaporization*Dynamic Viscosity of Fluid^0.5))^0.5)*(((Change in Enthalpy of Vaporization*Density of Vapour*Excess Temperature)/(Surface Tension*Temperature of Fluid))^2.3)
Heat transfer coefficient by convection for stable film boiling
Go Heat Transfer Coefficient by Convection = 0.62*((((Thermal Conductivity of Vapor^3)*Density of Vapour*Acceleration due to Gravity*(Density of Liquid-Density of Vapour)*(Change in Enthalpy of Vaporization+(0.68*Specific Heat of Vapour)*Excess Temperature))/(Dynamic Viscosity of Vapour*Diameter*Excess Temperature))^0.25)
Heat flux to nucleate pool boiling
Go Heat Flux = Dynamic Viscosity of Fluid*Change in Enthalpy of Vaporization*(((Acceleration due to Gravity*(Density of Liquid-Density of Vapour))/(Surface Tension))^0.5)*(((Specific Heat of Liquid*Excess Temperature)/(Constant in nucleate boiling*Change in Enthalpy of Vaporization*Prandtl Number))^3.0)
Enthalpy of evaporation to nucleate pool boiling
Go Change in Enthalpy of Vaporization = ((1/Heat Flux)*Dynamic Viscosity of Fluid*((Acceleration due to Gravity*(Density of Liquid-Density of Vapour))/(Surface Tension))^0.5*((Specific Heat of Liquid*Excess Temperature)/(Constant in nucleate boiling*(Prandtl Number)^1.7))^3)^0.5
Enthalpy of evaporation given critical heat flux
Go Change in Enthalpy of Vaporization = Heat Flux/(0.18*Density of Vapour*(((Surface Tension*Acceleration due to Gravity*(Density of Liquid-Density of Vapour))/(Density of Vapour^2))^0.25))
Critical heat flux to nucleate pool boiling
Go Heat Flux = 0.18*Change in Enthalpy of Vaporization*Density of Vapour*((Surface Tension*Acceleration due to Gravity*(Density of Liquid-Density of Vapour))/(Density of Vapour^2))^0.25
Heat transfer coefficient due to radiation for horizontal tubes
Go Heat Transfer Coefficient by Radiation = [Stefan-BoltZ]*Emissivity*(((Wall Temperature^4)-(Saturation Temperature^4))/(Wall Temperature-Saturation Temperature))
Emissivity given heat transfer coefficient by radiation
Go Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature)))
Heat transfer coefficient by radiation
Go Heat Transfer Coefficient by Radiation = (Heat Transfer Coefficient by Boiling-Heat Transfer Coefficient by Convection)/0.75
Heat transfer coefficient in film boiling
Go Heat Transfer Coefficient by Boiling = Heat Transfer Coefficient by Convection+0.75*Heat Transfer Coefficient by Radiation
Heat transfer coefficient for convection
Go Heat Transfer Coefficient by Convection = Heat Transfer Coefficient by Boiling-0.75*Heat Transfer Coefficient by Radiation

Emissivity given heat transfer coefficient by radiation Formula

Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature)))
ε = hr/([Stefan-BoltZ]*((Tw^4-Ts^4)/(Tw-Ts)))

What is boiling

Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

How to Calculate Emissivity given heat transfer coefficient by radiation?

Emissivity given heat transfer coefficient by radiation calculator uses Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature))) to calculate the Emissivity, The Emissivity given heat transfer coefficient by radiation formula is defined as is the measure of an object's ability to emit infrared energy. Emissivity is denoted by ε symbol.

How to calculate Emissivity given heat transfer coefficient by radiation using this online calculator? To use this online calculator for Emissivity given heat transfer coefficient by radiation, enter Heat Transfer Coefficient by Radiation (hr), Wall Temperature (Tw) & Saturation Temperature (Ts) and hit the calculate button. Here is how the Emissivity given heat transfer coefficient by radiation calculation can be explained with given input values -> 1.790686 = 1.5/([Stefan-BoltZ]*((300^4-200^4)/(300-200))).

FAQ

What is Emissivity given heat transfer coefficient by radiation?
The Emissivity given heat transfer coefficient by radiation formula is defined as is the measure of an object's ability to emit infrared energy and is represented as ε = hr/([Stefan-BoltZ]*((Tw^4-Ts^4)/(Tw-Ts))) or Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature))). Heat Transfer Coefficient by Radiation is the heat transferred per unit area per kelvin, Wall Temperature is the temperature at the wall & Saturation temperature is the temperature for a corresponding saturation pressure at which a liquid boils into its vapor phase.
How to calculate Emissivity given heat transfer coefficient by radiation?
The Emissivity given heat transfer coefficient by radiation formula is defined as is the measure of an object's ability to emit infrared energy is calculated using Emissivity = Heat Transfer Coefficient by Radiation/([Stefan-BoltZ]*((Wall Temperature^4-Saturation Temperature^4)/(Wall Temperature-Saturation Temperature))). To calculate Emissivity given heat transfer coefficient by radiation, you need Heat Transfer Coefficient by Radiation (hr), Wall Temperature (Tw) & Saturation Temperature (Ts). With our tool, you need to enter the respective value for Heat Transfer Coefficient by Radiation, Wall Temperature & Saturation Temperature 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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