Labs

The use of computers in engineering design has become critically important because designs have become more complex—because synthetic materials have become more common in designs, and because testing new designs has driven up product costs and extended time-to-market. Thus, effective computer simulation and analysis to complement testing has become an extremely important component of all phases of product engineering design. For this reason, computer simulation, modeling, and analysis is integrated into essentially all mechanical engineering courses.

The computer lab is restricted but open to all mechanical engineering students, including graduate students, faculty, and staff on a 24/7 basis. 

With more than 30 computers and access to a wide array of specialized software, most course instructors use this lab resource. Many instructors who have courses that include physical labs also assign computer lab exercises. Some instructors reserve the lab for training sessions so students can benefit from a structured, organized introduction to complex applications.

This lab, fondly called the "machine shop," accompanies the Design for Manufacturing course. It is also accessible to qualified senior students when needed for prototype manufacturing/testing in capstone projects. It gives students hands-on experience with the relationships between an effective design and a manufacturable product. A key part of this lab course is offering students a healthy dose of industrial safety training. Every lab session is carefully monitored to ensure that students follow all safety instructions and proper behavior.

Working in teams, students make a multi-component product from raw stock using a band saw, milling machine, lathe, drill press, CNC machines, taps and dies, common hand tools, and basic gauges for dimensional quality inspection. We stress that this lab is not to train students to become machinists. Instead, the lab exposes mechanical engineering students to the critical need to produce clear, concise, and accurate designs for parts that can be manufactured effectively, precisely, economically, and quickly. This lab focuses on the importance of strong design skills in a successful engineering career.

In addition to gaining experience with conventional machining operations, students can use 3D printing and laser cutting and engraving to enhance their product designs. Students also learn the most efficient way to convey their design goals to machinists and manufacturing personnel both by using properly dimensioned machine drawings and by learning correct terminology for verbal descriptions.

Mechanical engineers are often challenged to design complex systems that involve fluidic or hydraulic components that require a keen understanding of the underlying physics of moving, pressurized liquids. The Fluids Lab follows the curriculum of the Fluid Mechanics course and complements computer lab exercises that model various fluidic systems. Students gain direct, hands-on experience translating theory and math into practical, visible, and measurable results.

In the lab, students encounter three experiments that are at the core of an engineering introduction to fluid mechanics.

• Venturi apparatus: In this experiment, students gain an understanding of velocity and pressure gradients by virtue of moving liquid in a convergent-divergent conduit. The Venturi principle is central to the operation of a carburetor, which most mechanical engineering students understand, and the design of flowmeters. The Venturi principle makes use of the Bernoulli effect, which is applicable to internal and external flows, for example, airflow moving around wings to keep passenger planes in the air (as long as they move).
• Jet impact: In this experiment, students study the forces created by the impact of a water jet against flat and hemispherical vanes. In a later course, students will revisit the vane shape design for efficient power generation from a turbine.
• Pipe friction: In this experiment, students learn to control the flow of a fluid through a long, narrow pipe using their understanding of the Reynolds Number. This number is a characteristic measure of flow and differentiates between laminar flow and turbulent flow. Laminar flow is smooth and "unruffled," and resembles the way a telescoping antenna is extended. Turbulent flow is rough and scrambled, characterized by twisting, turning, and tumbling as in a fast-moving stream. The flow structures and frictional losses are markedly different between these two regimes of flow.

Design engineers must be acutely aware of internal stresses in structural members that sustain loads. These loading effects can have a significant impact on the integrity and reliability of a complex mechanical system. By knowing these stresses and their effects on the system, the designer can select appropriate materials for the application and can find the correct size and shape to assure that the design is functional and safe.

Students experiment with and study tensile forces; torsional or twisting forces; and bending forces, such as found in a cantilevered beam. Examples of these forces are all around us. Tensile forces are found in elevator cables; torsional forces are found in drive shafts and axle shafts; and bending forces are found in structural designs, such as unsupported balconies that protrude from a building. Mechanical engineers are critically involved with the design of these components, many having significant safety implications.

Even more than the physical design, the mechanical engineer must consider the physical properties of the materials to ensure safety and functionality. This lab explores the mechanical properties of various materials, such as polyethylene, nylon, carbon, aluminum, steel—and sometimes even wood—and explores their suitability for unique applications. This lab uses materials testing systems along with strain gauge sensors to measure the stress and deformation of the test specimens. The measured information will be used to determine material properties, such as stiffness, strength, and ductility. Knowing these properties is essential in the design process used in junior level course of Design of Machine Elements (MNE 381) and senior design courses (MNE 497 and MNE 498).

The Materials Science Lab exposes mechanical engineering students to the important relationships between the chemical and atomic characteristics of materials and the physical and mechanical behaviors that can result from these and significantly influence the engineer's design choices. 

The lab experiments expose students to mechanical strength and hardness of various steel alloys and non-ferrous metals (aluminum, copper, brass) and various methods to change the mechanical properties, such as heat-treating and work hardening. Students also learn about the effect that the crystalline structure of metallic and synthetic materials has on their mechanical properties.

The lab features metallurgical microscopes, including a video microscope with analysis software and wall-mounted display monitor. In addition, students learn about hardness using Rockwell hardness testers and learn to etch and polish metal samples to reveal the grain structures. Doing this, students then correlate the grain structures to the mechanical properties.

Today, manufacturing jobs are shifting from hands on the manufactured products to hands on the robots that manufacture those products. Mechanical engineers design, install, program, maintain, and repair highly complex and advanced robotic systems. The future looks bright for engineers skilled in robot technology.

Robots are increasingly used in many areas of manufacturing and in many specialized applications in society—or in space. Robots, for example, can work 24/7 for weeks without taking a break. Moreover, robots are ideal for tasks that may be hazardous for humans, such as spray painting, welding, working with dangerous materials, and similar requirements. They excel at repetitive and tedious tasks and those that require extreme dexterity or strength. Robots are also essential for demanding tasks, such as searching for survivors in confined areas after a disaster or retrieving and removing a suspected bomb. Specialized robotic machines have explored the deepest parts of the ocean and crawled across the landscapes of Mars. Medical researchers are also experimenting with robots for specialized surgery.

Student access to the lab

Students, using their ID cards, have 24/7 access to our robotics lab, allowing them to complete experiments and assignments at times that best suit their busy schedules, including evenings and weekends. All students enrolled in the Robotics course have lab access for the duration of the semester and can gain access at other times for special projects.

The lab features four new computer-controlled robots with custom software, which helps students undertake challenging experiments that complement their classroom assignments. The lab is a senior-level environment that is not chaperoned, so students are expected to demonstrate the best behavior on their own. This lab has relatively few safety restrictions.

Engineering students engage in a senior project, which extends through the full senior year. These projects are sponsored by industry: a few big names, such as Raytheon, Lockheed Martin, General Dynamics, MBTA, United Technologies, as well as many medium and small companies and start-up companies. This exposure offers employers a chance to attract and evaluate potential new hires. The affiliation with industry brings realistic engineering design projects to our seniors—very often, engineering challenges that result in new or improved products or processes.

No one course in the curriculum teaches design; rather, all courses include teaching components that emphasize the design aspects of the specific material. Students must bring the lessons from their coursework to bear on the specific project and seek additional knowledge and guidance from technical advisors, usually faculty.

The Senior Lab gives the student teams a place to conduct experiments and to work on their prototypes. The lab also provides a secure and safe space, so their interim work can be left undisturbed.

The Senior Capstone Project is an achievement that is a source of pride to every student, can be included in the résumé, and can be the source of a meaningful discussion during a job interview. Beyond earning a grade and learning how to conduct a genuine "hands-on" engineering project, the capstone experience can be a valuable asset for securing that first professional position.

The Systems Design & Control Lab introduces students to the principles of control systems. The basics of mechanical, electrical, hydraulic, and pneumatic control systems are examined, and Programmable Logic Controllers (PLCs) are explored in some detail. Although this was once a physical lab with hands-on experiments, a recent switch to a computer-based virtual lab allows more flexibility and modernization.

Students design and build hydraulic/pneumatic control systems to respond to different but typical constraints and requirements found in various manufacturing, dynamic, and functional situations. These might, for example, be controlling fluid flow rate, speed, and force in a manufacturing factory. In most cases, the emphasis will be on designing and implementing a control system that is fully automatic and requires no human involvement.

A cornerstone of mechanical engineering is understanding the relationships among heat, energy, work, and power in both open and closed systems. This lab, with the accompanying computational lab exercises, develops a hands-on understanding of the theory taught in the companion course. Students explore how various types of work can create thermal imbalances, and how thermal imbalances can be exploited to produce work. Students are challenged to explain sources of error and explain the various ways that thermal energy can enter or leave a defined system.

The senior-level course draws heavily on mathematical descriptions of thermal processes and requires a firm grasp of the underlying physics of these systems and chemistry of reactions. Students explore thermal phenomena in four lab experiments:

• Transient Open System: teaches the basics of conservation of energy, one of the fundamental principles in thermodynamics. Students experiment with different quantities of water and varying temperatures and study the total energy of the system.
• Air Impulse Turbine: examines the work produced and measured from a small, air-driven turbine. Students measure the pressure, flow, and temperature of the supply air and the temperature of the discharge air to calculate the theoretical change of internal energy. Using a brake dynamometer, they then measure the actual power produced by the turbine and compare these values.
• Refrigeration: demonstrates the conversion of energy or work—in this case, the electric power required by a compressor—to the difference in temperature produces and the BTUs of heat conveyed from the "cold" side to the "hot" side.
• Bomb Calorimeter: calls upon students to use their chemistry knowledge to examine the energy produced by an exothermic reaction. Students use precision instrumentation to characterize the energy produced by combustion reactions of known and unknown fuel samples in an oxygen atmosphere.