Direct Diffuse Radiation From Surface 2 To Surface 1 Calculator

Heat Transfer Formula:

\[ q_{2 \to 1} = A_2 \times F_{21} \times J_2 \]

Surface Area of Body 2 (A₂):

m²

Radiation Shape Factor 21 (F₂₁):

Radiosity of 2nd Body (J₂):

W/m²

Heat Transfer from Surface 2 to 1 (q₂→₁):

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1. What is Direct Diffuse Radiation?

Direct diffuse radiation refers to the heat transfer between surfaces through radiation where the radiation is scattered or diffused rather than following a direct path. This calculator computes the heat transfer from surface 2 to surface 1 using the radiosity method.

2. How Does the Calculator Work?

The calculator uses the radiation heat transfer formula:

\[ q_{2 \to 1} = A_2 \times F_{21} \times J_2 \]

Where:

\( q_{2 \to 1} \) — Heat transfer from surface 2 to surface 1 (W)
\( A_2 \) — Surface area of body 2 (m²)
\( F_{21} \) — Radiation shape factor from surface 2 to surface 1
\( J_2 \) — Radiosity of the 2nd body (W/m²)

Explanation: The formula calculates the radiative heat transfer between two surfaces based on their geometry, orientation, and surface properties.

3. Importance of Radiation Heat Transfer

Details: Radiation heat transfer is crucial in thermal engineering, building design, solar energy systems, and various industrial processes where heat exchange between surfaces occurs without direct contact.

4. Using the Calculator

Tips: Enter surface area in square meters, shape factor (between 0 and 1), and radiosity in W/m². All values must be valid positive numbers with shape factor between 0-1.

5. Frequently Asked Questions (FAQ)

Q1: What is radiation shape factor?
A: Radiation shape factor (view factor) represents the fraction of radiation leaving one surface that directly impinges on another surface.

Q2: How is radiosity different from emissive power?
A: Radiosity includes both emitted radiation and reflected radiation from a surface, while emissive power only considers radiation emitted by the surface itself.

Q3: What are typical shape factor values?
A: Shape factors range from 0 (no direct view) to 1 (complete enclosure view), with values depending on surface geometry and orientation.

Q4: When is this calculation most applicable?
A: This calculation is most accurate for diffuse gray surfaces in thermal equilibrium with uniform surface properties.

Q5: What are the limitations of this approach?
A: This method assumes diffuse surfaces, uniform radiosity, and doesn't account for spectral effects or participating media between surfaces.