Document Type : Research Paper
This paper presents a study on estimation of heat transfer coefficient and thermal diffusivity parameters by use of analytical solutions and experimental data for regular geometries (infinite slab, infinite cylinder and sphere). Analytical solutions have a broad use in experimentally determining these parameters. These solutions, with use of experimental data, might give a greater advantage over use of other methods, e.g., the lumped system approach or empirical equations. In the present work, the method of finite integral transform (FIT) was used for solutions of governing differential equations. The temperature change at centerline location of cylindrical objects (Aluminum and Brass) were recorded to determine both the thermal diffusivity in a highly agitated water medium and heat transfer coefficient in air and water mediums . Then, with the known slop of the temperature ratio vs. time curve and radius of the cylindrical material, thermal diffusivity value or heat transfer coefficient may be determined. For all experiments, excellent agreement was obtained between the experimental results and the actual data. This method may also be used to find out the precise geometric location of the thermocouples placed in the samples to measure the temperature change. In this research, thermocouple location for a spherical object was determined. This technique would be much faster and easier compared to the other methods used for this objective.