How to Calculate Heat Flux

How to Calculate Heat Flux
••• nuclear power station image by david hughes from Fotolia.com

Heat flux, or heat transfer per rate unit area, is a useful quantity in applications such as determining the transfer of energy from a fuel plate to working fluid, such as in a pressurized water reactor.

    Measure the system parameters. Include uniform thickness of the material through which heat is flowing, and call it wall thickness, d. Include thermal conductivity, k, of this material. Measure (or estimate from system design parameters) the hot temperature (such as that of a heat source), Thot. Measure cold temperature (such as that of a working fluid), Tcold.

    Calculate heat transfer rate, Q. Q is measured in units of energy per unit time, such as BTU/hr or Watts. For a wall of uniform thickness d, with a thermal conductivity of k, an area of A, a hot temperature, Thot, and cold temperature, Tcold, solve Q with the following equation: Q = k*A(Thot - Tcold)/d. For example, using iron with a k = 79.5 (Watts/m K), a wall 1 cm thick, analyzed over 1 square meter, and Thot - Tcold = 111C (or degrees K, equivalently), Q = 882,450 Watts

    Remove units of area, A, to get heat flux, Q". Divide Q by the area, A, you used to solve for Q since Q" = Q/A. For example, the heat flux Q" in the step above is 882,450 Watts/1m^2 = 882,450 Watts/m^2. Note that you needed to include the area in the original Q calculation to cancel out the meter unit in the value of k.

Related Articles

How to Convert From BTU to Fahrenheit
How to Figure Out a Temperature Gradient
How to Calculate Thermocouple Sensitivity
How to Convert Lux to Candela
How to Calculate Boiler Heat Input Rate
How to Calculate Time to Heat Water
How to Convert Steam Flow to Megawatts
How to Calculate Heat Absorption
How to Calculate Thermal Stress
How to Calculate the Field Current in a DC Motor
How to Calculate Area From Width & Length
How to Convert Candle Power to Lumens
How to Calculate QCAL
How to Find the Area of Squares
How to Convert Centimeters to Meters
How to Calculate Ampacity
How to Calculate Arc Area
How to Calculate Joules
How to Convert CMH to BTU
How to Calculate DC Voltage

Dont Go!

We Have More Great Sciencing Articles!