The future of hydrogen as the automotive fuel of choice will require safe but economical production, distribution and transport. One of the risks specifically associated with hydrogen is detonation, especially in enclosed environments such as in production equipment. To assess this hazard, a simulation of detonation following a hydrogen leak in two realistic hydrogen production accident scenarios was performed. The first considered a pipe failure in an electrolyzer resulting in the release of 42 g of hydrogen while the second assumed a similar failure in a steam methane reformer enclosure leading to the leak of 84 g of hydrogen. A 2D simulation was performed using the concentration cloud as the initial condition and simulating ignition by adding sufficient energy to a small region. In both scenarios, relatively high impulse values were produced on the enclosure walls, which would produce important mechanical damage. Consequently enclosure design should take the magnitude of those values into account in order to limit the potential damage.

Laurie Bédard-Tremblay,
L. Bédard-Tremblay, L. Fang, L. Bauwens, Z. Cheng, A.V. Tchouvelev
University of Calgary
lbedardt@ucalgary.ca

Linkages and mechanisms have been studied in great detail since the 1800's and have been found in many applications in industry including robotics, machines, engines, and many other areas. Few if any have applied linkages as a means to steer a vehicle. Historically, the common automobile steering system is typically designed using gearing, in particular a rack and pinion, to manipulate the tie-rod. This paper proposes and analyzes an innovative three dimensional four-bar mechanism to steer a FSAE race car. This consists of coupled levers, one for each hand, which activates a spherical four-bar linkage that articulates the two tie-rods for steering. A closed-form kinematic model was used to prescribe parameters for a 3D model in SolidWorks. Mechanism performance was confirmed using COSMOSMotion. Results of this project were implemented in both a tabletop scale model as well as a prototype for a FSAE mini-formula one car. One of the unique attributes of this device is that by changing the geometry, the mechanical advantage can be non-linear, changing quickly (or slowly) throughout the mechanism motion.

John Lacy
University of Idaho
jlacy@vandals.uidaho.edu

Strength of muscles has been a topic of interest for several decades. As understanding increases about joints, muscles and tissues, it is valuable to recognize how the human body uses them together to produce a force. However, there is lacking research of healthy children and adolescents. This study measured differences in the isometric muscle strength among adolescents during the five Tanner stages of puberty (sexual development). Fifty subjects (25 boys and 25 girls, 6-15 years) with no known disabilities or leg injuries of dominant leg were tested from a small community at multiple angles for both flexion and extension of their dominant knee. A special device was designed and manufactured with a stationary torque transducer located at the center of rotation (axis of rotation) for each subject. Measurements were taken at three different angles of flexion and extension for each subject.

Jessica D. Sampson
University of Idaho
Sampsonj2@asme.org

Thermal conductivity and specific heat measurements have been performed on nanofluids containing aluminum oxide (Al2O3) nanoparticles in a base fluid of 60:40 ethylene glycol/water (60EG/40W) by mass. First, benchmark tests for the thermal conductivity of air, water and 60EG/40W mixture were performed. The measured values were compared with data available in the published literature. A maximum error of 2.8% for air, 1.7% for water and 1.8% for 60EG/40W were observed. Similarly benchmark tests for specific heat were conducted for water and 60EG/40W. A maximum error of 6% for water and 8.5% for 60EG/40W were observed. After confirming the accuracy of both the apparatus and the procedure, measurements were conducted for determining the thermal conductivity and specific heat of Al2O3 nanofluids over a temperature range of 25°C to 90°C for a nanoparticles volume concentration of 0 to 10 %. Empirical correlations were developed for thermal conductivity and specific heats of nanofluids as a function particle volume concentration and temperature. These correlations will be useful to study the heat transfer characteristics of nanofluids in industrial heat exchangers, automotive cooling and building heating.

Ravikanth S. Vajjha and Debendra K. Das
University of Alaska Fairbanks
ftrsv@uaf.edu

Bridge-wire initiators are used to ignite explosives in many different industries such as aerospace and automotive. In testing these initiators, standards require ignition of charges inside of closed vessels where pressure and temperature measurements are taken. Taking this data is problematic due to the extreme transient conditions that often mask sensor failure. Currently, periodic static and dynamic tests of the pressure sensors are used to test functionality but dynamic performance is often in question. A promising new way to test dynamic performance of pressure transducers is to use them to measure the adiabatic compression of gas in a Ballistic Compressor. A ballistic compressor consists of two pressure vessels (one large and one small) separated by a piston that creates extremely high pressures in the smaller vessel when the piston is released. Highly repeatable and reliable pressure environments result from using this device. A ballistic compressor prototype has been designed using principles of fluid mechanics and machine design, but its operating regime is uncertain. In this work, design failure mode effects analysis (DFMEA) was used to define and prioritize ballistic compressor failure modes. Failure modes with the highest risk priority number (RPN) were plug threads, seal integrity, and trigger integrity. Structural analysis with Algor, machine design calculations based on pressure vessel standards, and literature review on O-ring life revealed that the limiting failure mode was the plug threads at a maximum operating pressure of 30 ksi. This is above the maximum pressures that are anticipated in bridge-wire testing, and minimizes uncertainty associated with pressure transducers in energetic testing.

Tye Reid
University of Idaho
Reid4766@vandals.uidaho.edu