2006-697: ACTIVE-LEARNING BASED LABORATORY FOR INTRODUCTORY THERMODYNAMICS COURSE

This paper describes a laboratory component for a sophomore level introductory engineering thermodynamics course. The class is core component of the Engineering Science curriculum at Borough of Manhattan Community College. The introduction of the lab is part of a greater curricular modification to invigorate engineering education at BMCC by integrating real world situations and active-learning based instructions into classroom. Thermodynamics is an abstract subject. Many students lack first hand experience with the subject matter. They resort to memorization rather than gaining analytical understanding of concepts. The Lab component is designed to create an opportunity for students to accumulate experiential learning and gain problem-solving skills. The lab consists of six modules: Real Time Measurements, Hand Cranked Generator and Calorimeter, Piston/Cylinder Device Gas Heat Engine, Propane Fueled Steam Rankin Cycle, Refrigeration/Air Conditioner Cycle, and Natural Gas Fueled Internal Combustion Engine. The lab component allows students to gain an overall knowledge of instrumentation of thermal systems, and the relationship between theoretical and physical systems. It also promotes teamwork and communication between students, particularly, in data collection, analysis and report preparation. Groups of 3 to 4 students work together on each project and prepare report.


Introduction
It is well known that students learn and retain more as they become more engaged with instructional materials.Reisman and Carr 1 concluded that students learn 20% of the material taught by hearing, 40% by seeing and hearing, and 75% by seeing, hearing, and doing.Furthermore, people learn concepts and skills better when sharing in teams than working in isolation.Thus, most of newer educational approaches emphasize active learning by students, in which instructors move from being lecturers to coaches.The laboratory is an ideal setting to introduce such hands-on activities where students can learn by experiencing.The physical devices and simulations used in the laboratory provide active experiences for the students, allowing them to make parametric adjustments, observe the effects in related thermodynamics variables, and reflect upon key concepts of the course 2 .

Class Objectives
The Additionally, it is also desired students gain an overall knowledge of instrumentation and measurement techniques of thermal systems, and become aware of differences between theoretical models and physical systems.

Laboratory Components
To meet the above requirements an active-learning based laboratory component was developed to complement the class.It was incorporated in ESC211 for the first time in fall, 2005.The thrust of it is a set of six workshops, which include:

Workshops Modules
In the first workshop students are introduced to real-time data measurements.The instruments used are temperature sensors, pressure gauges and low friction piston/cylinder device.The workshop objective is to allow students to familiarize themselves with the computerized data acquisition system.They also learn about gauge and absolute pressure using a low friction piston/cylinder device.
In the second workshop, transfer of mechanical energy to heat is explored; see Water temperature, voltage and current output of the generator are recorded in real time as the generator is cranked.The electric power is obtained from the instantaneous voltage and current.The power output is then compared to the resulting increase in thermal energy of the water and the inner calorimeter cup.The module illustrates how mechanical energy is converted to electrical work and in turn to thermal energy of a system and its resulting temperature increase.Students are able to operate and analyze this system in detail, allowing them to determine the efficiency of the facility and suggest possible modifications for further improvement.Nine sensors are installed at key locations around the cycle.Using the data obtained from these sensors, many analysis options are available.For example, the entire system first law efficiency can be analyzed.Adjusting the throttle valve to change steam flow rate admitted to the turbine provides multiple steady state conditions.By incorporation of these strategically placed instruments, not only can the cycle be analyzed but also individual components.The boiling temperature / pressure of water can be verified in the boiler to study water saturation conditions, and the thermodynamic efficiency of the turbine can be monitored and compared to computer simulations.
Due to large numbers of data collected, analysis is accomplished using MS Excel and XL thermal fluid.XL thermal fluid is a MS Excel function for carburetor is retrofitted for natural gas.The generator is connected to a bank of light bulbs and electric heaters.Switching on and off different numbers of light bulbs and electric heaters load the generator, which in turn loads the engine.The electric power delivered is measured using a hand-held power-meter.A fuel flow meter records the fuel consumption.A magnetic sensor in vicinity of the flywheel enables engine speed to be determined by measuring the frequency with which spark plug fires.The purpose of this laboratory assignment is to provide participants an opportunity to study the different terms involved in the 1st law of thermodynamics and obtain system-wide efficiency.

Remarks
Thermodynamics is a discipline that deals with energy utilization as constrained by Natural laws that are expressed in fundamental properties, and with its applications via mathematical models.Its study is basic to science and engineering and is a core subject in many engineering curricula.The above-discussed laboratory is an attempt to give students hands-on experience with fundamental properties and concepts.
The Thermodynamics laboratory has been offered for the first time in fall, 2005.The introduction of the lab took up class time and consequently, the designated syllabus could not be entirely covered.This situation was alleviated by a team-based approach to the lab.Teams (a group of 3-4 students) perform the necessary measurements together and prepare a group report.Team members helped one another in understanding the materials and learning the concepts.The team-based approach promoted peer instruction, which in turn helped to reduce the need to lecture and compensated for time used by the lab.
Fig 1.The set-up is a classic experiment where electrical energy (provided by a hand-cranked Page 11.155.3generator) is converted to thermal energy in a container of water; see Fig 2. The equipment includes a 10-Ohm heating resistor inside a double-walled calorimeter cup.

Fig 9 .
Fig 9. Internal combustion engine and light bulb bank Engineering science program at Borough of Manhattan Community College offers ESC 211, a sophomore year introductory thermodynamics course.The class learning Page 11.155.2objectivesareparallel to those of ABET2000 A-K criteria.The course emphasizes fundamentals and their applications.It mainly requires students to able to:• State the First Law and to define heat, work, thermal efficiency and the difference between various forms of energy.