Mechanical and Aerospace Engineering

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.

Fluid Dynamics.  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.

Material Characterization.  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.

Nanomaterials.  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 internships.

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.

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.

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 mm or 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.

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. 

 
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 measuring 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 velocity of 641 m/s and a unit Reynolds number of 4.9 x 107/m . Typical 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 thickness of 0.85 mm.

Thermal Sciences.  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.