The laboratory curriculum in
mechanical and aerospace engineering has been structured to help students
integrate physical understanding with theoretical knowledge, and to familiarize
them with advanced engineering systems and instrumentation for
multidisciplinary problem solving in the 21st century. Laboratory exercises
begin with introductions to basic measurement concepts and culminate in the exploration
of complex, open-ended engineering problems. Facilities are continuously
upgraded to provide an effective learning environment. State-of-the-art
facilities, which are integral parts of the undergraduate laboratory
experience, include a stereolithography rapid prototyping machine, a Mach 4
supersonic wind tunnel, and a pair of industrial-quality robotic arms. The
undergraduate and research laboratory space is integrated physically to provide
personal, often informal, contact and communication among undergraduate
students, graduate students, and faculty. Undergraduate participation in
research is widespread and strongly encouraged. A summary listing of facilities
comprising the undergraduate laboratories follows.
Design and Manufacturing.
Mechanical and aerospace engineering
analysis, design, and synthesis problems are investigated in the Computer-Aided
Design (CAD) laboratory. Students gain hands-on experience on CAD workstations
through exercises in computer-aided drafting, 3-D solid modeling and parametric
design, simulation of kinematic and dynamic problems, and stress analysis using
finite element methods. Extensive software is available, including AutoCAD,
Inventor, Pro/Engineer, ANSYS, Matlab, Maple, and programming in C/C++ and
Fortran. Exposure to advanced manufacturing techniques is provided through
machine-shop training as well as utilization of two Rapid Prototyping (RP)
machines (3-D Viper System and Stratasys Fused Deposition 3000 System). CAD and
RP are available on the internet and the design iteration cycles have been
reduced significantly. A complete design cycle experience from concept to
fabrication, followed by evaluation, has been implemented.
Dynamics and Controls.
Prediction and control of the
response of structures subject to dynamic loadings are a central component of
mechanical and aerospace engineering design and analysis. Experiments have been
designed to illustrate dynamic response of single and multiple degree of
freedom systems, as well as to carefully examine frequency and amplitude
response of structural components. Diagnostics are conducted using advanced
laboratory computers and digital spectrum analyzers, in addition to
conventional strain gages and impact hammers.
Fundamental principles and advanced
systems involving fluid flows, ranging from demonstrating Bernoulli's principle
to assessing the lift and drag characteristics of airfoil designs, are examined
in the undergraduate curriculum. Facilities include four low-speed wind tunnels
and a mach 4 supersonic wind tunnel; a large free-surface water tunnel also is
used for undergraduate participation in independent or sponsored research.
Advanced instrumentation includes hot-film anemometry with computerized data
acquisition and optical diagnostics techniques.
Mechanical properties of materials
are examined in the newly completed solid mechanics laboratory. Facilities
include three Instron tensile testing machines with digital data acquisition
and control and three hardness-testing machines. Laboratory exercises have been
structured to highlight phenomena associated with deformation and failure of
engineering materials. Additional research quality facilities available to
undergraduates include larger MTS and Instron testing machines. These
instruments are used in research on biomechanical systems and composite
materials, respectively. Undergraduate research also may be conducted in a high
pressure, ~100,000 psi, materials testing/processing laboratory.
Nanostructured materials synthesis
and characterization are examined in the laboratories. Facilities include
flame-based chemical vapor condensation/deposition chambers and plasma
reactors. Laboratory exercises involve synthesis of nanoparticles and carbon
nanotubes, probing of the processing flow field using laser-based spectroscopic
techniques, and characterization of the properties of the resulting
nanomaterials. The lab courses include introduction to atomic force microscopy,
scanning electron microscopy, X-ray diffraction, and scanning mobility particle
sizing. These dual-purpose educational/research laboratories engage significant
undergraduate independent research, as well as high school outreach through
Robotics and Mechatronics.
Critical concepts in system control
as well as advanced theories of robotics and mechatronics are investigated
using a series of industrial robots including a three-axis SCARA robot (Adept
Cobra s600), a three-axis planar transportation system (Genmark AVR-3000), and
two five-axis general purpose robots (Mitsubishi RV-M2). Kinematics, motion
planning, hybrid force/position control for object manipulation, and automated
assembly operations are the topics addressed in the laboratory exercises. This
dual-purpose educational/research laboratory enjoys a particularly high degree
of undergraduate student participation in the research component.
A variety of energy-related
experiments are offered in the undergraduate curriculum from basic sciences of
thermodynamics and heat transfer to assessing the performance and environmental
impact of a steam turbine power generating system. Specific experiments include
convection and radiation heat transfer exercises, and experiments carried out
in an internal combustion engines laboratory and the steam power generator
facility. A partnership with local industry to design the applied engineering
laboratories has provided students with realistic simulations of actual
engineering problems and scenarios.
Supersonic Wind Tunnel.
Rutgers University's Mach 3.45
supersonic wind tunnel (SWT) facility is a fixed-Mach number,
blowdown-to-atmosphere tunnel with dried air as the test gas. SWT is fed by a
compressed air storage system, that supplies a total volume of 8 m3 of air, pressurized to 16.6 MPa. Expansion
of the flow is accomplished using a half-nozzle, creating Mach 3.45 flow at the
entrance to the test section. The test section is a square cross-sectional area
152 mm x 152 mm.
SWT operates at a typical stagnation temperature (290 K), and variable stagnation
pressure typically around 1.5 MPa. These conditions correspond to a freestream
unit Reynolds number of
4.9 x 107/m
run times at these conditions are approximately 10-15 seconds. The tunnel
boundary layer develops naturally and is fully turbulent at the entrance to the
test section. Previous measurements have established a boundary layer momentum
Schlieren Imaging. The schlieren system is a z-type configuration, using a 29.21 cm diameter parabolic mirror to collimate light prior to passing through the test section. The light source for the schlieren system is a Thorlabs mounted LED, which produces white light. A second parabolic mirror reflects the light to a set of optics that help to steer the beam into a CCD camera. For schlieren experiments, data can be obtained with the knife edge positioned either vertically or horizontally, to image density gradients tangential or normal to the flow direction, respectively.
Images are recorded
using a LaVision 12-bit Pro-X camera. The camera is a thermo-electrically
cooled CCD camera with a resolution of
1600 x 1200 pixels,
and a maximum
quantum efficiency of 55% at 500 nm. The camera can operate at a maximum frame
rate of 29 Hz; therefore, the data obtained are not time-resolved. Imaging of
the full field of view is performed with a Nikon Nikkor 105 mm camera lens.
Timing for the system is accomplished using a LabSmith LC880 programmable
experiment controller, that supplies a 5 V square-wave TTL signal trigger to
the camera. Finally, post-processing of the acquired images is in Matlab.
Particle Image Velocimetry.
Particle image velocimetry (PIV) data
will be obtained using a LaVision stereoscopic-PIV system, consisting of a pair
of 16-bit scientific CMOS (sCMOS) cameras, with a pixel resolution of 2560-2160 pixels. The cameras can be arranged in a stereoscopic configuration to
provide for correction to out-of-plane particle motion and slight misalignment
of the laser sheet with the viewing plane. A pair of 105 mm Nikon Nikkor lenses
can be used for large field of view imaging of the flow field, while zoomed-in
measurements can be made using a pair of 200 mm lenses. The lenses will be
mounted to Scheimpflug adapters. As the tunnel operates for a minimum of 10
seconds, 150 vector fields can be obtained during a single run, whereas 10-20
runs may be required for converged statistics for a given flow condition.
The light source
for the PIV will be provided by a Quantel Evergreen 200 mJ/pulse double-pulsed
Nd:YAG laser, which produces 532 nm light at a maximum rate of 15 Hz. The laser
will be expanded into a thin laser sheet, with a desired thickness of ~1.5 mm.
Timing for the cameras and the laser will be provided through either a LaVision
programmable timing unit (PTU) or externally using a Stanford Research Systems
digital delay generator.
Processing of the PIV raw images will be performed
using LaVision DaVis v8.3 software.
Seeding options for
SWT are currently under investigation. Constraints for the selection of proper
seeding include safety, particle size, and particle response. To address the
safety and environmental concerns, mineral oil options are being considered.
Use in comparable tunnel facilities have confirmed particle sizes of 1
less, which allows for Stokes numbers of under 0.1. As has been demonstrated by
Samimy & Lele (1991), this is sufficient for faithfully tracking the flow.