Experimental Analysis of Free Convection Heat Transfer From a Nonisothermal Plate

Heat transfer by convection has been studied extensively since about 1900, but it is probably still the least understood of the three types of heat transfer due to its dependency on fluid dynamics. The most thoroughly studied cases are forced convection over a flat plate and free convection from a vertical isothermal plate. In a large number of engineering applications, it is necessary to calculate the heat transfer from a surface which is heated locally such as a fin heated at its root. There has been very little analytical or experimental work done for this particular case in which the internal conduction within the plate is coupled with the convection away from the plate. The purpose of this investigation is to study the free convection heat transfer from a thin vertical flat plate of uniform thickness which is heated locally at various vertical positions. The laws which govern the heat transfer phenomenon are reviewed as they relate to the problem. Due to the complexity of the resulting equations, it will be necessary to rely on experimentation to determine the heat and heat transfer coefficient will be calculated from the experimental data and the results will be compared to a more idealized case consisting of an isothermally heated plate. The report will first present the governing laws as they apply to the problem. An explanation of the experimental analysis will be next, followed by a discussion of the results. Finally, rather brief conclusions and recommendations will be given