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Chapter 1: Problem 13

What is heat flux? How is it related to the heat transfer rate?

Short Answer

Expert verified
Answer: Heat flux (q") is the rate at which heat energy is transferred per unit area, and heat transfer rate (Q) is the total amount of heat energy transferred per unit time. They are related through the area (A) with the formula: Q = q" × A, where q" is the heat flux (W/m²), A is the area (m²), and Q is the heat transfer rate (W).

Step by step solution

01

1. Define Heat Flux

Heat flux, denoted by q", is the rate at which heat energy is transferred through a unit area of a given material, per unit time. It is a measure of how quickly heat is moving through a surface or a region. The units of heat flux are Watts per square meter (W/m²).
02

2. Define Heat Transfer Rate

The heat transfer rate, denoted by Q, is the amount of heat energy transferred per unit time. It is a measure of how much heat is being transferred in a certain process or across a given region. The units of heat transfer rate are Watts (W).
03

3. Relate Heat Flux to Heat Transfer Rate

Heat flux (q") and heat transfer rate (Q) are related through the area (A) across which the heat transfer is occurring. Mathematically, this relationship is given by the formula: \[Q = q" \times A\] Here, \(q"\) is the heat flux (W/m²), \(A\) is the area (m²), and \(Q\) is the heat transfer rate (W). In conclusion, heat flux is the rate at which heat energy is transferred per unit area, while the heat transfer rate is the total amount of heat energy transferred per unit time. They are related through the area across which the heat transfer occurs.

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