Simultaneous determination of thermal diffusivity and surface heat transfer coefficient for selected foods | |
| Author | Guo, Rongping |
| Call Number | AIT Thesis no. AE-97-6 |
| Subject(s) | Food--Thermal properties Thermal diffusivity |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A transient method was developed to determine thermal diffusivity of food products simultaneously with heat transfer coefficient from heating and cooling curves. For measuring temperature-time history of a food product, an experimental set-up was designed and developed to conduct heating and cooling experiments on cylindrical or square bar shaped food product with different size using different medium velocity to cover a wide range of experimental conditions. Newton-Ralphson iterative technique was used in the developed numerical computation scheme to determine thermal diffusivity value by assuming Biot number. The partial differential equation for transient heat conduction was solved by CrankNilcoson finite difference method to calculate center temperature of test samples. By comparing the slope and intercept of experimental and calculated ln(TR) vs. time plots, the thermal diffusivity and surface heat transfer coefficient values were determined simultaneously when the two temperature profiles fitted in the best way. The standard deviation of thermal diffusivity values determined from cylindrical samples were small comparing with the mean value of a. These results indicated that the transient method had high repeatability and accuracy. The results obtained from square bar shaped samples were higher than those obtained from cylindrical test samples. |
| Year | 1997 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Jindal, Vinod K. ; |
| Examination Committee(s) | Athapol Noomhorm, Vincent, Jean-Claude; |
| Scholarship Donor(s) | State Education Committee of China; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1997 |