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The objective of this study is to develop a robust framework to model shock-turbulence interactions that happen in many engineering applications dealing with compressible flows. The model is essentially a hybrid algorithm to address the conflict between turbulence modeling and shock-capturing requirements. A skew-symmetric form of a co-located finite volume scheme with minimum aliasing errors is implemented to model the turbulent region in the combination of a semi-discrete, central scheme to capture the discontinuities with sufficiently low dissipation to minimize the effect of large eddy simulation (LES) for turbulent flows. To evaluate the effectiveness of the model, LESs are conducted to study the interaction of stationary shocks with turbulent flows. The simulations of the shock-turbulence interaction show the same physical trends as previously published results for high-fidelity DNS and LES.

Longitudinal vortex generation is a common technique for enhancing heat transfer performance. It can be achieved by employing small flow manipulators, known as vortex generators (VGs), which are placed on the heat-transfer surface. The vortex generators can generate longitudinal vortices, which strongly disturb the flow structure, and have a significant influence on the velocity and temperature distributions, causing improved thermal transport. In this work, numerical simulations are conducted for a horizontal rectangular channel with and without a pair of longitudinal vortex generators. The vortex generators are fitted vertically on the bottom surface of the channel. The Computational Fluid Dynamics (CFD) analysis aims to acquire a better understanding of the flow structure and heat transfer mechanisms induced by longitudinal vortex generation. The simulation is performed using ANSYS Fluent, and three flow inlet velocities are considered: 1.38 m/s, 1.18 m/s, 0.98 m/s.

Online road profiling capability is required for automotive active suspension systems to be realized in a commercial landscape. The challenges that impede the realization of these systems include a profiler’s ability to maintain an optimal resolution of the oncoming road profile (spatial frequency). Shifting of the profile measurement frame of reference due to body motion disturbances experienced by the vehicle also negatively impacts profiling capability. This work details the early development of a corrective look-ahead road profiling system (CLARPS) and its control logic. The CLARPS components are introduced and additional focus will be given to the development of the angle generating function (AGF) and how it drives the ability of the system to optimize look-ahead viewing angles for the best spatial frequency resolution of a road profile. The CLARPS simulation environment is demonstrated with numerical comparison of simulated road profiles at varying vehicle speeds.

Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. In high speed applications, rolling element forces and gyroscopic moments can be significantly high compared to the applied forces acting on a bearing. Such moments create a “driving” torque causing outer race to creep. In this paper a mathematical model for the dynamics of a rolling element in a high speed bearing is derived. Preload values counterbalancing the torque driving the outer race to rotate can be predicted from this model. An attempt to experimentally measure this torque using a specially designed apparatus with integrated strain gauge torque sensor is also described. Both model and experimental measurements are aimed at understanding, and therefore preventing bearing failures due to outer race (creep) rotations.

All-wheel drive (AWD) vehicle performance considerably depends not only on total power amount needed for the vehicle motion in the given road/off-road conditions but also on the total power distribution among the drive wheels. In turn, this distribution is largely determined by the driveline system and its mechanisms installed in power dividing units. They are interwheel, interaxle reduction gears, and transfer cases. The paper presents analytical methods to evaluate the energy and, accordingly, fuel efficiency of vehicles with any arbitrary number of the drive wheels. The methods are based on vehicle power balance equations analysis and give formulas that functionally link the wheel circumferential forces with slip coefficients and other forces acting onto an AWD vehicle. The proposed methods take into consideration operational modes of vehicles that are tractive mode, load transportation, or a combination of both.

AASHTO I-Beam is a standard structural concrete part for bridge sections. The flexural performance of an AASHTO I-Beam is critical for bridge design. This paper presents an application of Digital Image Correlation (DIC) Method in full-scale AASHTO I-Beam flexural performance study. A full-scale AASHTO I-Beam pre-stressed with steel strands is tested by three-point bending method. The full-scale AASHTO I-Beam is first loaded from 0 kips to 100 kips and is then released from 100 kips to 0 kips. A dual-camera 3D Digital Image Correlation (DIC) system is used to measure the deflection and strain distribution during the testing. From the DIC results, the micro-crack generation progress during the loading progress can be observed clearly from the measured DIC strain map. To enable such a large-scale DIC measurement, the used DIC setup is optimized in terms of the optical imaging system and speckle pattern size.

The reliability of engine valve springs is a very important issue from the point of view of warranty. This paper presents a combined experimental and statistical analysis for predicting the fatigue limit of high tensile engine valve spring material in the presence of non-metallic inclusions. Experimentally, Fatigue tests will be performed on valve springs of high strength material at different stress amplitudes. A model developed by Murakami and Endo, which is based on the fracture mechanics approach, Extreme value statistics (GUMBEL Distribution) and Weibull Distribution will be utilized for predicting the fatigue limit and the maximum inclusion size from field failures. The two approaches, experimental and theoretical, will assist in developing the S-N curve for high tensile valve spring material in the presence of non-metallic inclusions.

Mechanical engineering students at Lawrence Technological University complete a five-credit hour capstone project: either an SAE collegiate design series (CDS) vehicle or an industry-sponsored project (ISP). Students who select the SAE CDS option enroll in a three-semester, three-course sequence. Each team of seniors designs, builds, and competes with their vehicle at one of the SAE CDS events. Three years after implementing major changes to the course structure and content, the three-semester capstone design sequence is revisited. Finalized learning objectives are presented and the sequence is assessed with a mix of direct, indirect, and anecdotal assessment. Student performance, as measured directly with design reports, milestones, and project completion, is good. Of the five Lawrence Tech CDS teams, only one has failed to be ready for competition since the changes were implemented.

In this study, a new nonlinear correlation between Brinell hardness and ultimate tensile strength is proposed. The correlation factor in this case is higher than that found in the current literature. The ultimate tensile strength is replaced by an equivalent hardness expression in the Modified Universal Slopes Method. This change results in fatigue parameters that are predicted using hardness, true fracture ductility, and modulus of elasticity. This new fatigue life prediction approach is compared with the original Modified Universal Slopes method and experimental data in literature. This method is valid for steel with hardness that ranges from 150HB to 660HB. The results show that this method provides better approximations of the strain-life curves when compared with the Modified Universal Slopes and experimental data.

The 1999 Lawrence Technological University (LTU) drive train consists of a sprocket and chain assembly that delivers the torque, developed by a 600cc Honda F3 engine, to the rear wheels. The torque is transferred through a limited-slip, torque sensing differential unit comprised of a gear set in a student designed housing. The 1999 differential is a second-generation aluminum housing. The idea of using aluminum was first attempted with the 1998 team who successfully completed and used aluminum despite much complexity and a few design flaws. Therefore, in the LTU Formula Team's continuing effort to optimize the design, a new less complex design was conceived to house the gear set. This innovative design reduces the number of housing components from three in 1998, to two in 1999.

A vehicle-level data acquisition (DAQ) system was developed and implemented on the Lawrence Technological University (LTU) Baja SAE vehicle. This low-cost Arduino-based DAQ system is capable of accurately and repeatedly measuring Baja SAE specific vehicle parameters and storing them for offline analysis. While expandable for the needs of future teams, the developed DAQ system includes measurement of vehicle wheel speed, CVT pulley speeds, suspension position, CVT belt temperature, steering load, and steering angle. The development of the DAQ system architecture and the development of the angular speed and suspension position measurement subsystems are the focus of this work. The processes followed and lessons learned can be used by other Baja SAE and SAE Collegiate Design Series. Each measurement subsystem was designed, fabricated, integrated, and validated on the bench and in-vehicle.

This paper analyzes the difference in impact response of the forehead of the Hybrid III and THOR-NT dummies in free motion headform tests when a dummy strikes the interior trim of a vehicle. Hybrid III dummy head is currently used in FMVSS201 tests. THOR-NT dummy head has been in development to replace Hybrid III head. The impact response of the forehead of both the Hybrid III dummy and THOR dummy was designed to the same human surrogate data. Therefore, when the forehead of either dummy is impacted with the same initial conditions, the acceleration response and consequently the head Injury criterion (HIC) should be similar. A number of manufacturing variables can affect the impacted interior trim panels. This work evaluates the effect of process variation on the response in the form of Head Injury Criterion (HIC).

This paper discusses how to effectively design and set-up an ideal spring/damper combination in a low-mass open wheeled racecar to properly control vehicle handling and gain optimum performance of the system. The system that will be discussed is outfitted with a non-parallel, unequal length SLA suspension that was designed and raced at the 2001 Formula SAE competition. The focus of this paper will be more on how to choose an ideal suspension set-up for a low-mass open wheeled racecar, while considering the various variables that can affect the system as a whole. To properly design a suspension, a passive system will be used, and then the performance gains of a semi-active system will be introduced and discussed.

This paper presents an experimental investigation of flow field instabilities in a centrifugal pump impeller at low flow rates. The measurements of pump hydraulic performance and flow field in the impeller passages were made with a hydraulic test rig. Analysis of Q-ΔP-η data and flow structures in the impeller passages were performed. In the present work, the effect of various flowrates on centrifugal pump impeller performance was analyzed based on pump measured parameters. The impeller’s geometry was modified, with positioning the curved spacer at the impeller suction side. This research investigates the effect of each inlet curved spacer model on pump performance improvement. The hydraulic performance and cavitation performance of the pump have been tested experimentally. The flow field inside a centrifugal pump is known to be fully turbulent, three dimensional and unsteady with recirculation flows and separation at its inlet and exit.

The objective of this research is to develop a component based enhanced production process after End of Line (EOL) testing. This process will add more quality validation evaluations, but will not require any disassembling of the parts or damage to them. It will help the suppliers to avoid scrap and rework parts as well as General Motors (GM) to reduce warranty and recalls. An Enhanced Production Process was implemented in March, 2016 at a supplier in Mexico. The Enhanced Audit Station implementation is to ensure that the supplier is satisfying the Production Part Approval Process (PPAP) requirements. The most important four components are: Touch Appearance Lighting and Color (TALC), Appearance Approval Report (AAR), Dimensional Checks, and Function Testing. Through statistics, a pilot study was conducted to correlate the selected variables to reduce warranty.

An accurate prediction of elasto-plastic cyclic deformation becomes extremely important in design optimization. It also leads to more accurate fatigue life prediction and hence weight savings. In paper presents a two-stage notch root prediction method. This is based on a correction expression to Neuber's rule notch strain amplitude as the first stage, and a linear interpolation scheme as the second stage. The accuracy of this method is assessed by comparing the predicted results with the results obtained from elasto-plastic finite element analysis. Various types of steels with different yield strengths were used in this study. Notch deformation behavior under cyclic variable amplitude loading conditions was monitored for a double notched flat plate and a circumference notched round bar to cover plain stress and plain strain conditions. Elastic as well as elasto-plastic finite element analyses are performed.

The initiative of this paper is focused on improving the heat dissipation from the pressure wheel of a laser welding assembly in order to achieve a longer period of use. The work examines the effects of different geometrical designs on the thermal performance of pressure wheel assembly during a period of cooling time. Three disc designs were manufactured for testing: Design 1 – a plain wheel, Design 2 – a pierced wheel, and Design 3 – a wheel with ventilating vanes. All of the wheels were made of carbon steel. The transient thermal reaction were compared. The experimental results indicate that the ventilated wheel cools down faster with the convection in the ventilated channels, while the solid plain wheel continues to possess higher temperatures. A comparison among the three different designs indicates that the Design 3 has the best cooling performance.

The experimental methods focused on utilizing the newly developed NOVA induction heating and hardening manufacturing process as an adapted method to produce high performance engine valve springs. A detailed testing plan was used to evaluate the expected and theorized possibility for fatigue life enhancement. An industry standard statistical analysis method and tools were employed to objectively substantiate the findings. Fatigue cycle testing using NOVA induction-hardened racing valve springs made of ultra-high tensile material were compared to data for springs with traditional heat treatment and those with standard processing. The results were displayed using Wöhler and modified Haigh fatigue life diagrams. The final analysis suggests that NOVA processed springs have a seemingly slight, yet significant benefit in fatigue life of 5 - 7% over springs processed through a competing method.

Recently, there has been a new method for setting bearing preload on tapered roller bearings in a power transmission system. To move this new method into production, an analytical model that relates the bearing preload to the stiffness of the bearing was developed. This work develops an analytical model that links the preload on multi-row tapered roller bearings to the stiffness of the power transmission system. This study also validates the proposed analytical model by comparing it to both previous work and commercially available simulation software. The analytical model has shown that it is highly sensitive to the number of rollers in the bearing, which is discussed in this work.

This paper proposes and evaluates improvements to a crash simulation of a fuel delivery module in a fuel tank. The simulations were performed in ANSYS/LS-DYNA. Deviations between the original simulation and test data were studied and reasons for the deviations hypothesized. These reasons stemmed from some of the simplifying assumptions of the model. Improvements consisted of incorporating plasticity and strain rate effects into the material models. Performance criteria were also directly incorporated into the material models such that non-performing portions of the model could be deactivated during the simulation. Finally, solid-fluid interactions were added into the simulation to include the momentum transfer from fuel to the fuel delivery module. It was previously thought that effects of a crash would be most severe on the module when the fuel tank was empty and the module was full with fuel.