Convective Heat Transfer Rate
Relate surface-to-fluid temperature difference to total convective heat flow.
Try this formula
Calculate heat transfer rate; positive from surface to fluid or choose another supported quantity.
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Try this formula
Calculate heat transfer rate; positive from surface to fluid or choose another supported quantity.
Use decimals or scientific notation, such as 1.2e3. Calculations update as you type.
Heat transfer rate; positive from surface to fluid
Enter the known values to see the result.
Use an appropriate average heat transfer coefficient for the actual fluid and flow. Surface and bulk-fluid temperatures are represented by the chosen averages. Radiation and conduction through other paths are separate contributions.
Difficulty
Intermediate
Read time
5 min
Prerequisites
Basic algebra, mechanics, and consistent SI units
Source
Teng-Jui Lin — CHEM E 330 — Transport Processes IReference equation: Newton's law of cooling. FormuLab wrote new explanations, assumptions, applications, and numerical examples. Multiplied the source heat flux by surface area to obtain total heat rate.
Adapted from Teng-Jui Lin, Equation Sheets — Mechanical Engineering Expansion, under CC BY 4.0.
Adapted standard equations and added original lesson text, variables, SI examples, and assumptions. Multiplied the source heat flux by surface area to obtain total heat rate.
Definition
A convective coefficient summarizes the thermal boundary layer near a surface. Multiplying the source heat flux by area gives a heat rate; the direction follows the sign of the surface-to-fluid temperature difference.
Variables & Units
| Symbol | Meaning | Units |
|---|---|---|
| Heat transfer rate; positive from surface to fluid | ||
| Average convective heat transfer coefficient | ||
| Heat transfer surface area | ||
| Surface absolute temperature | ||
| Bulk-fluid absolute temperature |
Real-World Applications
Surface cooling
Estimate heat flow from a warmer component into a fluid.
Thermal models
Represent a convective boundary in a thermal balance.
Worked Example
Problem
A 0.5 m² surface is at 350 K in a 300 K fluid, with h = 25 W/(m²·K). Find the convective heat rate.
Given
Solution
Final Answer
Contents
Info
Tools
Source & review
Reference equation: Newton's law of cooling. FormuLab wrote new explanations, assumptions, applications, and numerical examples. Multiplied the source heat flux by surface area to obtain total heat rate.
Adapted from Teng-Jui Lin, Equation Sheets — Mechanical Engineering Expansion, under CC BY 4.0.
Adapted standard equations and added original lesson text, variables, SI examples, and assumptions. Multiplied the source heat flux by surface area to obtain total heat rate.
Assumptions
- • Use an appropriate average heat transfer coefficient for the actual fluid and flow.
- • Surface and bulk-fluid temperatures are represented by the chosen averages.
- • Radiation and conduction through other paths are separate contributions.
Languages
FormuLab is a study reference. Verify formulas, units, assumptions, and course-specific conventions before relying on them.