Gunnar Tamm

TEACHING THERMODYNAMICS VIA ANALYSIS OF THE WEST POINT POWER PLANT

Thermodynamic analyses can be performed based on energy-gross and exergy-net quantities. These topics are discussed in the context of the United States Military Academy at West Points power plant and the project that students work on as a part of their course requirements for three courses. A systematic, detailed, and comprehensive methodology is presented based on recent experiences that can be a standard for similar academic instruction of thermodynamic concepts and power plants. A well-defined case study for the classroom will yield more effective learning of and inspire a greater appreciation for critical power technologies.

On the Analysis of the Aerodynamic Heating Problem

A complete analytical solution to the problem of aerodynamic heating is lacking in heat transfer textbooks, which are used for undergraduate and graduate education. There are many issues that are very important from a convective heat transfer point of view. In practice, poor analyses lead to poor design, thus faulty manufacturing. Since, over the years analysis has given way to numerical studies, the instructors do not take the necessary time to go through analytical details. Thus the students just use the results without any awareness of how to get them and the inherent limitations of the analytical solution. The only intent of this paper, therefore, is to present the detailed analytical study of the aerodynamic heating problem.

On the Similarity Solution for Condensation Heat Transfer

Analytical solutions for laminar film condensation on a vertical plate are integral to many heat transfer applications, and have therefore been presented in numerous refereed articles and in most heat transfer textbooks. Commonly made assumptions achieve the well known similarity solution for the Nusselt number, heat transfer coefficient, and film thickness. Yet in all of these studies, several critical assumptions are made without justifying their use. Consequently, for a given problem one cannot determine whether these restrictive assumptions are actually satisfied, and thus, how these conditions can be checked for validity of the results. This study provides a detailed solution that clarifies these points.

Teaching Design in Context

As a result of recent curriculum revisions, the mechanical engineering faculty at the United States Military Academy teaches the formal design process “just in time” for students to apply the process to their capstone design projects. The design process consists of several phases and incorporates many engineering tools. During the initial offering of the course, Mechanical Engineering Design, instructors assigned students to capstone design teams early in the course. As the instructor taught the design process, team members applied the concepts to their capstone project. Based on instructors’ and students’ feedback, faculty revised the course structure to teach the design process in the context of a simple, in-class design project (design a portable illumination device) during the first half-semester. All in-class exercises were collaborative, hands-on experiences based on the project. To reinforce topics introduced in class and ensure all students develop a firm foundation in the design process, a separate common customer need (a device to store a West Point class ring) was the focus of all individual homework. Each student developed a design, built a prototype, and wrote an individual design report. Subsequent to formal design process instruction, students formed capstone teams and began their one and one-half semester capstone design projects. Results indicate that students more thoroughly understood the design process and its associated engineering tools allowing capstone teams to progress more efficiently through conceptual design; order parts, build prototypes, and test prototypes much earlier than the previous year; and enjoy a successful capstone experience.

Field Improvised Electric Arc Welder

Generations of warfighters have benefited from field manuals to provide instructional knowledge for creating improvised devices and capabilities from readily available resources. These devices range from simple fundamentals to classified advances in materials and technologies. A collaborative effort between the United States Military Academy and the U.S. Army Armament Research, Development and Engineering Center is creating the latest repertoire of capabilities for soldiers in theater. An improvised electric arc welder was developed to provide field expedient capabilities to them. Both AC wall power and DC power from car batteries were utilized to demonstrate various options. This paper provides the electrical models, experimental results and lessons learned. Welds were tested in a tension tester to determine their viability.

Energy Security Analysis for West Point Training Camps

The United States Military Academy has been charged with reaching Net Zero Energy consumption by 2020. Feasibility assessments to this point have neglected the field facilities used for military training, which are remote locations susceptible to power loss and subject to a higher rate structure for electricity than the rest of the installation. An energy security analysis methodology is described and applied to the training camps at West Point. This began with identifying the mission of the camps and critical power needs based on discussions with the customer, the Director of Cadet Military Training. Details of power and energy usage along with supply and delivery cost structure were provided by the utility and the facility Energy Manager. Conventional and renewable resource potentials were assessed to meet the load profile within financial constraints and funding opportunities unique to a federal government agency. The final recommendation is to incorporate three different technologies: a 50 kW photovoltaic solar system installed through a power purchase agreement, two small scale hydropower systems totaling 30 kW, and a lake based cooling system to provide air conditioning. The installation of these three systems would move the installation closer to the Net Zero Energy goal and lower the energy requirements to provide cooling. Altogether the proposed project would pay back in 16 years with an expected lifespan of 20–30 years. Batteries, generators, and pumped hydro were also examined as possible energy storage options and to shave the peak electrical load. However, the lack of on peak/off peak pricing made these options less viable. These recommendations will increase West Point’s energy security, progress towards the Net Zero Energy goal, and provide cost savings over current utility expenditures.© 2014 ASME

Waste Heat Recovery From Generators in the Deployed Army

Electrical power generation in austere settings, such as combat zones, places a heavy burden on the US Army; high costs in both dollars and lives lost require that every drop of fuel be used effectively and efficiently. In remote locations such as combat outposts (COPs) and small forward operating bases (FOBs) in Afghanistan, electrical power derived from the Army’s standard Advanced Medium Mobile Power Sources (AMMPS) generator is even used to heat water for showers and heat living spaces. This heating requires conversion of thermal energy to mechanical energy, which is then converted to electrical energy and back to heat. Thus, a significant fuel savings could be realized through the more efficient production of heat. A combined heat and power system is proposed; efficiency is increased by routing the generator exhaust through simple ducting to a standard gas hot water heater to produce hot water with waste heat. With funding from the U.S. Army Rapid Equipping Force, cadets and faculty at the United States Military Academy designed, built and tested a system for under

Enhancement of Electronics Cooling in the OH-58D Kiowa Warrior

1,000 in parts which was readily coupled to a 5 kW AMMPS generator to produce hot shower water. Results indicate a possible fuel savings of 1500–2000 gallons per year, 20–35% increased fuel utility, and the ability to provide 10–20 five gallon showers during every 5 hours of operation of each 5 kW generator. At a fuel cost of

Improving Turret Control on Military Vehicles

20–50 per gallon in the deployed environment, and considering the large inventory of deployed generators, the payback for the Army could be tremendous.© 2014 ASME

On the Teaching of Performance Evaluation and Assessment of a Combined Cycle Cogeneration System

The Bell OH-58 Kiowa helicopter was first introduced in 1969 and has undergone several retrofits to the present OH-58D Kiowa Warrior (KW) model. The KW has become heavily loaded with electronics for communications, weapons and sensors to enhance its overmatch capability against the enemy. However, the ability to cool the heating load of these systems is being stretched thin, especially in current hot operational environments. As a result, electrical component failure has resulted in reduced operational availability and extended maintenance periods. This paper presents a theoretical study performed by cadets and faculty at the U.S. Military Academy, in support of a request by Army PEO Aviation to explore alternatives. The thermal and flow characteristics of the current KW electronics bays are analyzed to identify weaknesses and potentials for quick retrofits. Several novel solutions are proposed and assessed, including redirection and enhancement of the flow, as well as cooling of the intake air or direct cooling of the electronics through mechanical, thermoelectric, evaporative and heat pipe methods.