The discussion focuses on calculating the time required for the temperature of a metal tank to drop from θ2 to θ1, considering factors such as tank dimensions, material properties, and heat transfer coefficients. Key parameters include the surface area of the tank, the temperature difference, and the heat transfer coefficient, which varies significantly based on insulation. The conversation emphasizes the complexity of determining the heat transfer coefficient, suggesting experimental measurement or manufacturer data as essential methods. Recommended resources include introductory heat transfer textbooks covering "unsteady" or "transient" one-dimensional heat transfer, Biot number, and Heisler charts.
PREREQUISITESEngineers, thermal physicists, and students involved in heat transfer analysis, particularly those working with metal tanks and thermal systems.
Thank you for the replyanorlunda said:The most important parameters are surface area of the tank, temperature difference in and out, and heat transfer coefficient.
The heat transfer coefficient is small for well insulated walls, and large for no insulation and thin walls. It is very difficult to calculate. Typically, you would need to measure it by experiment, or to get a value from the manufacturer of the tank.
Thank you!gmax137 said:Any introductory heat transfer textbook, look for: "unsteady" or "transient" one-dimensional heat transfer; Biot number; Heisler charts.
This problem can be solved approximately or in any amount of detail as needed.
There is not really a single "coefficient" for this because the problem is very complex. You need to know the effect of convection inside the tank, conduction through the walls of the tank and convection of the air outside the tank. You should be aware of this before you look for a simple answer to your problem.Thatrandomdudeacross said:Assuming I have the coefficient, how would I go on from there?