The topic of heat transfer is traditionally taught as an upper level, lecture-style course to mechanical engineering students. Such courses do not provide students with ways to see and feel the important heat transfer concepts at hand. As a way to overcome this, novel, hands-on workshops have been designed and implemented into a heat transfer class taught to junior level mechanical engineering students. Two types of experimental workshops were created and used in two different years of a section of a heat transfer class. In the first year, twelve workshops were designed which included live demos so that the students could see and feel different modes of heat transfer while taking data and seeing real-time plots of temperature and heat flux in different experiments. The workshop introduced each topic the students would be learning in the lecture and was performed the week before the actual lecture on the topic. Each workshop included easily available materials, thermocouples, heat flux sensors, and data acquisition instruments for the students to use. The workshops also served replacements for what would be the third lecture of the week. Results from a concept inventory test given at the end of the first year showed a significant difference on certain question between an experimental group of students who had the workshops and a control group who took the traditional class lecture. However, there were still concepts and topics that the experimental group did not show improvement. They also showed a lack of improvement in their problem solving skills for quiz and test problems. For the second year of the experiment, the workshops were restructured quite a bit. The original 12 workshop format was cut down to only six in order to focus on the ones the students seemed to have benefited from the most. The workshops were also changed into a video-enhanced format where the students would watch a video of the experiment being done while also having the materials in front of them to place their hands on themselves. The students could therefore see and feel what was physically happening and still perform the experiment while watching real-time, pre-recorded plots of heat flux and temperature without worrying about making sure their setup was right and acquiring good results. The new video-enhanced workshops also included control volume and resistance diagrams for each experiment in order to help the students relate the workshops and concepts back to problems on their quizzes and tests. Results from these workshops seemed to show some statistical significance between the experimental and control groups on concept questions given on quizzes throughout the semester, but there was no difference on any questions from the ten concept questions given on the final exam. However, surveys taken by the students indicate that they believed the workshops did help them to understand the concepts in a real-world sense and that they helped them understand the class material better overall. Aside from the results of the workshops on the students learning, this study concludes with an analysis of important heat transfer concepts and how to test them. There is much debate about the underlying concepts in the topic of heat transfer and a thorough analysis on what specific concepts are important for students to know must be addressed. Many heat transfer concept questions on current concept inventories have more to do with thermodynamics and the mixing of the two topics is itself a misconception. / Master of Science

This work focuses on the development of a system to noninvasively estimate blood perfusion using thermal methods. This is accomplished by the combination of a bioprobe, biothermal model, and parameter estimation techniques. The probe consists of a heat flux sensor and surface thermocouple placed in contact with tissue while the opposite side is cooled by jets of room temperature air. The biothermal model predicts the temperature and heat flux within tissue and probe based upon the input of blood perfusion and the thermal contact resistance between probe and tissue. Parameter estimation techniques are developed that use the model to simultaneously estimate blood perfusion and contact resistance based on experimental heat flux and/or temperature. A gradient based system minimizes a sum of squares error function based on either or both heat flux and temperature. This system is tested on human forearms and in controlled flow rate experiments using tissue phantoms. Blood perfusion estimates from the controlled experiments are positively correlated with experimental flow rate. Experimental measurements and statistical analysis show distinct variations in the heat flux signal and rises in perfusion estimates with increasing flow rate. This research validates the use of thermal and parameter estimation methods to develop a practical, noninvasive probe to clinically measure blood perfusion. / Master of Science