Use of an inverse method to determine natural convection heat transfer coefficients in unsteady state

The purpose of this study is to evaluate the efficiency of an inverse method to determine the variation of convective heat transfer coefficients in the unsteady state inside building enclosures. The experimental system is mainly composed of a vertical, heated, flat plate where natural convection heat flow is generated and of a radiative source which can impose a known flux condition. The inverse method calculates the total heat flux by conduction along the vertical flat plate, together with surface temperatures. Subtracting the local contribution of the radiative heat flux from the total heat flux gives the average convective heat flux at different heights of the plate. For various boundary conditions, it is then possible to determine the values. of the convective heat exchange coefficients. Uncertainty calculations relative to these results confirm the reliability of the inverse method developed.