Heat Flux (q) =
= - Thermal Conductivity (k) × Temperature Gradient (ΔT)/ Distance (Δx) The Heat Flux "q" Heat flux, often measured in watts per square meter (W/m²), provides a measure of how much heat energy passes through a unit area per unit time. It quantifies the flow of thermal energy from a region of higher temperature to a region of lower temperature. Thermal Conductivity "k" Thermal conductivity, represented by "k," is a material property. It tells us how well a material can conduct heat. Materials with high thermal conductivity allow heat to flow more readily, while those with low thermal conductivity resist heat flow. Temperature Gradient ΔT The temperature gradient, ΔT, is the difference in temperature between two points in the material. It indicates the direction in which heat flows, moving from the higher-temperature point to the lower-temperature point. Distance Δx The distance, Δx, over which heat is transferred is crucial. It tells us how far the heat travels through the material. A larger distance results in more heat being transferred.Also Check - Electric Field Formula
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Solved Example 2: Question: A pizza is being baked in an oven. The temperature inside the oven is 250°C, and the outer surface of the pizza reaches a temperature of 80°C. Calculate the heat flux from the oven air to the pizza if the pizza has a thickness of 0.01 meters and a thermal conductivity of 0.5 W/m·K. Solution: Step 1: Identify the given values: - Initial Temperature (T1) = 250°C (convert to Kelvin) = 523 K - Final Temperature (T2) = 80°C (convert to Kelvin) = 353 K - Thickness (Δx) = 0.01 meters - Thermal Conductivity (k) = 0.5 W/m·K Step 2: Apply the heat flux formula: Heat Flux (q) = - Thermal Conductivity (k) × (T1 - T2) / Thickness (Δx) Step 3: Plug in the values: q = -0.5 W/m·K × (523 K - 353 K) / 0.01 meters Step 4 : Calculate the heat flux: q = -34,000 W/m² These two examples illustrate the calculation of heat flux in different scenarios. If you have more questions or need additional examples, feel free to ask.Also Check - Strain Formula