ROBERT HARDER | George Fox University (original) (raw)
Uploads
Papers by ROBERT HARDER
Rail, ASME/IEEE Joint Conference, 2001
At present there are approximately 2.5 million three-piece bogies operating under North American ... more At present there are approximately 2.5 million three-piece bogies operating under North American freight vehicles. Although US bogie manufacturers offer a variety of designs to vehicle builders, central to all of these bogie designs are the nonlinear frictional characteristics inherent in the bogie suspension. These characteristics derive from the dynamic behaviour of the friction wedges. Friction wedges are small triangular
2005 Annual Conference Proceedings
Teams of students designed and developed experiments for a new four-credit course in heat transfe... more Teams of students designed and developed experiments for a new four-credit course in heat transfer at George Fox University as a part of their initial laboratory experience. Over the past three years, students have developed eight experiments that cover a broad range of conduction, convection and radiation phenomena. The new heat transfer course consists of three hours of lecture and one three-hour laboratory per week. Teams which consisted of two students each designed and developed laboratory experiments for this new course at a fraction the cost that it would have taken to purchase similar experiments from an outside vendor. In the process, the students gained useful insights into thermal design methodology and developed a greater appreciation for the fundamentals of heat transfer, than would have been realized by simply performing "canned" experiments. Student design teams prepared a full laboratory handout as well as an operations manual as a part of their laboratory experiment design projects. Teams were given a fixed budget and were required to submit a cost analysis with their final report. Oral and written presentations were required for each of the student teams, along with the satisfactory demonstration of their working experiment. Laboratory experiment details and the design process followed by each student team will be outlined for several of the experiments developed, including: heat conduction in a tapered rod, natural convection in a vertical flat plate, forced air turbulent convection inside a heated tube, overall heat transfer coefficient in a double pipe heat exchanger, film condensation heat transfer coefficient and combined radiation and natural convection of a horizontal cylinder. Rubrics were used to evaluate the student design process, as well as written and oral presentations.
In 2000, George Fox University expanded its engineering program from a 3/2 program to a complete ... more In 2000, George Fox University expanded its engineering program from a 3/2 program to a complete four year engineering program providing a Bachelor of Science in Engineering with concentrations in both electrical and mechanical engineering. 2004 saw the first graduates from the program which became ABET accredited the following year. Very early in the program development, it was decided that the senior capstone experience would be a multidisciplinary experience. The small class sizes (9-10 seniors in the first three years) also enabled the program to focus on a single project in the initial years and expanded to two projects to accommodate the 17 seniors in the 2006/2007 academic year. While many senior capstone experiences are constructed to focus on the design experience, we decided to expand this focus. By their senior year, George Fox University engineering students have already experienced a number of significant design experiences. This wealth of prior design practice enables ...
Wear, 2006
During a wheel slide the frictional heat generated at the contact interface causes intense heatin... more During a wheel slide the frictional heat generated at the contact interface causes intense heating of the adjacent wheel material. If this material exceeds the austenitising temperature and then cools quickly enough, it can transform into martensite, which may ultimately crack and cause wheel failure. A knowledge of the distribution of the heat partitioned into the wheel and the rail and the resulting temperature fields is critical to developing designs to minimize these deleterious effects. A number of theoretical solutions have appeared in the literature to model the thermal aspects of this phenomenon. The objective of this investigation was to examine the limitations of these solutions by comparing them to the results of a finite element analysis that does not incorporate many of the simplifying assumptions on which these solutions are based. It was found that these simplified solutions can produce unrealistic results under some circumstances.
Rail, ASME/IEEE Joint Conference, 2001
At present there are approximately 2.5 million three-piece bogies operating under North American ... more At present there are approximately 2.5 million three-piece bogies operating under North American freight vehicles. Although US bogie manufacturers offer a variety of designs to vehicle builders, central to all of these bogie designs are the nonlinear frictional characteristics inherent in the bogie suspension. These characteristics derive from the dynamic behaviour of the friction wedges. Friction wedges are small triangular
2005 Annual Conference Proceedings
Teams of students designed and developed experiments for a new four-credit course in heat transfe... more Teams of students designed and developed experiments for a new four-credit course in heat transfer at George Fox University as a part of their initial laboratory experience. Over the past three years, students have developed eight experiments that cover a broad range of conduction, convection and radiation phenomena. The new heat transfer course consists of three hours of lecture and one three-hour laboratory per week. Teams which consisted of two students each designed and developed laboratory experiments for this new course at a fraction the cost that it would have taken to purchase similar experiments from an outside vendor. In the process, the students gained useful insights into thermal design methodology and developed a greater appreciation for the fundamentals of heat transfer, than would have been realized by simply performing "canned" experiments. Student design teams prepared a full laboratory handout as well as an operations manual as a part of their laboratory experiment design projects. Teams were given a fixed budget and were required to submit a cost analysis with their final report. Oral and written presentations were required for each of the student teams, along with the satisfactory demonstration of their working experiment. Laboratory experiment details and the design process followed by each student team will be outlined for several of the experiments developed, including: heat conduction in a tapered rod, natural convection in a vertical flat plate, forced air turbulent convection inside a heated tube, overall heat transfer coefficient in a double pipe heat exchanger, film condensation heat transfer coefficient and combined radiation and natural convection of a horizontal cylinder. Rubrics were used to evaluate the student design process, as well as written and oral presentations.
In 2000, George Fox University expanded its engineering program from a 3/2 program to a complete ... more In 2000, George Fox University expanded its engineering program from a 3/2 program to a complete four year engineering program providing a Bachelor of Science in Engineering with concentrations in both electrical and mechanical engineering. 2004 saw the first graduates from the program which became ABET accredited the following year. Very early in the program development, it was decided that the senior capstone experience would be a multidisciplinary experience. The small class sizes (9-10 seniors in the first three years) also enabled the program to focus on a single project in the initial years and expanded to two projects to accommodate the 17 seniors in the 2006/2007 academic year. While many senior capstone experiences are constructed to focus on the design experience, we decided to expand this focus. By their senior year, George Fox University engineering students have already experienced a number of significant design experiences. This wealth of prior design practice enables ...
Wear, 2006
During a wheel slide the frictional heat generated at the contact interface causes intense heatin... more During a wheel slide the frictional heat generated at the contact interface causes intense heating of the adjacent wheel material. If this material exceeds the austenitising temperature and then cools quickly enough, it can transform into martensite, which may ultimately crack and cause wheel failure. A knowledge of the distribution of the heat partitioned into the wheel and the rail and the resulting temperature fields is critical to developing designs to minimize these deleterious effects. A number of theoretical solutions have appeared in the literature to model the thermal aspects of this phenomenon. The objective of this investigation was to examine the limitations of these solutions by comparing them to the results of a finite element analysis that does not incorporate many of the simplifying assumptions on which these solutions are based. It was found that these simplified solutions can produce unrealistic results under some circumstances.