Heat Transfer Coefficient of Thin Steel Sheet on Water

[xharville]

I was wondering if anyone knew the heat transfer coefficient of a thin steel sheet on top of water. It is vital that I find this answer because it is a major part of my research. I found one formula which stated that the U value could be found by using the formula 1/U= x1/k1 + x2/k2. I wanted to know if this formula was correct or if not, what would be a better formula to use. Thanks for the help.

 

[Astronuc]

That depends on whether or not the water is flowing.

Static water would involve pure heat conduction, whereas flowing water would involve convection as well as conduction.

 

[piercas]

The heat transfer coefficient of a thin steel sheet on water depends on several factors such as the temperature difference between the sheet and the water, the thermal conductivity of the steel and water, and the surface area of the sheet in contact with the water. It is not a fixed value and can vary depending on these factors.

The formula you mentioned, 1/U= x1/k1 + x2/k2, is known as the overall heat transfer coefficient equation and can be used to calculate the overall heat transfer coefficient for a system with multiple layers or materials. However, it may not be suitable for your specific case as it requires the individual heat transfer coefficients (x/k values) for each layer, which may not be readily available for a thin steel sheet on water.

A more suitable formula to use in this case would be the Nusselt number, which is a dimensionless number that relates the convective heat transfer coefficient to the thermal conductivity and thickness of the steel sheet. It is given by Nu = hL/k, where h is the convective heat transfer coefficient, L is the characteristic length (thickness) of the steel sheet, and k is the thermal conductivity of the steel.

To determine the convective heat transfer coefficient, you can use empirical correlations or perform experiments to measure it directly. The Nusselt number can then be used to calculate the overall heat transfer coefficient using the equation U = Nu*k/L.

In conclusion, the heat transfer coefficient of a thin steel sheet on water is not a fixed value and can be calculated using the Nusselt number equation. It is important to consider all the relevant factors and use appropriate equations or correlations to obtain an accurate value for your specific case.