Radiation Absorbed By Small Body Per Unit Of Its Surface Area Calculator

Formula Used:

\[ G_{abs} = \alpha \times [Stefan-BoltZ] \times T^4 \]

Absorbed Radiation (G_abs):

W/m²

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1. What is Radiation Absorbed by Small Body?

The radiation absorbed by a small body per unit of its surface area represents the amount of radiant energy that the body absorbs from its surroundings. This is a fundamental concept in thermodynamics and heat transfer, particularly relevant in radiation heat exchange calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ G_{abs} = \alpha \times \sigma \times T^4 \]

Where:

\( G_{abs} \) — Absorbed radiation (W/m²)
\( \alpha \) — Absorptivity (dimensionless, 0-1)
\( \sigma \) — Stefan-Boltzmann constant (5.670367 × 10⁻⁸ W/m²K⁴)
\( T \) — Temperature (Kelvin)

Explanation: The formula calculates the radiation energy absorbed by a body based on its absorptivity coefficient and the fourth power of the absolute temperature of the radiation source.

3. Importance of Radiation Absorption Calculation

Details: Accurate calculation of absorbed radiation is crucial for thermal analysis, heat transfer engineering, solar energy systems design, and understanding radiative heat exchange in various industrial and environmental applications.

4. Using the Calculator

Tips: Enter absorptivity value between 0 and 1, and temperature in Kelvin. Ensure temperature is above absolute zero (0 K) for valid calculations.

5. Frequently Asked Questions (FAQ)

Q1: What is absorptivity?
A: Absorptivity is a dimensionless coefficient between 0 and 1 that represents the fraction of incident radiation that a surface absorbs. A value of 1 means perfect absorption (black body), while 0 means no absorption.

Q2: Why is temperature raised to the fourth power?
A: This follows the Stefan-Boltzmann law, which states that the total radiant heat energy emitted from a surface is proportional to the fourth power of its absolute temperature.

Q3: What is the Stefan-Boltzmann constant?
A: It's a physical constant denoted by σ that appears in the Stefan-Boltzmann law, with a value of approximately 5.670367 × 10⁻⁸ W/m²K⁴.

Q4: Can this calculator be used for any material?
A: Yes, as long as you know the correct absorptivity value for the material at the specific wavelength of interest.

Q5: How does this relate to emissivity?
A: For gray bodies, absorptivity equals emissivity at the same temperature and wavelength (Kirchhoff's law of thermal radiation).