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The Nexus vehicle was designed and built for Transport Canada at the University of Saskatchewan to demonstrate that a safety compliant single passenger commuter vehicle could attain extremely low fuel consumption rates at modest highway speeds. Experimentally determined steady state fuel consumption rates of the Nexus prototype ranged from 1.6 L/100 km at 61 km/hr up to 2.8 L/100 km at 121 km/hr. Fuel consumption rates for the Society of Automotive Engineers (SAE) driving cycle tests were 4.5 L/100 km for the SAE Urban cycle and 2.0 L/100 km for the SAE Interstate 55 cycle. The efficiency of the power train was determined using a laboratory dynamometer, enabling the road test results to be compared to the results from an energy and performance simulation program. Predicted fuel economy was in good agreement with that determined experimentally. Widespread use of single passenger commuter vehicles would substantially reduce current transportation energy consumption.

Extensive experimental data was collected for CBN surface grinding of M2 tool steel to determine the relative grinding performance of three different vitrified CBN abrasive grit sizes. The results define the relationships between the grinding forces, the material removal rate and the resulting specific energy, while providing an evaluation of the ground surface characteristics including surface finish, microstructure, hardness and residual stress. The interaction of grinding process inputs including wheel grit size, workpiece velocity and depth of cut are considered, and a series of single factor tests and a 23 factorial test are conducted. The grinding forces increase linearly with increasing material removal rate for the range of parameters tested.

An analytical model based on “vortex sound” theory was investigated for predicting the frequency, the relative magnitude, the onset, and the offset of self-sustained interior pressure fluctuations inside a vehicle with an open sunroof. The “buffeting” phenomenon was found to be caused by the flow-excited resonance of the cavity. The model was applied to investigate the optimal sunroof length and width for a mid-size sedan. The input parameters are the cavity volume, the orifice dimensions, the flow velocity, and one coefficient characterizing vortex diffusion. The analytical predictions were compared with experimental results obtained for a system which geometry approximated the one-fifth scale model of a typical vehicle passenger compartment with a rectangular, open sunroof. Predicted and observed frequencies and relative interior pressure levels were in good agreement around the “critical” velocity, at which the cavity response is near resonance.

Original equipment manufacturers and their customers are demanding more efficient, lighter, smaller, safer, and smarter systems across the entire product line. In the realm of automotive, agricultural, construction, and earth-moving equipment industries, an additional highly desired feature that has been steadily trending is the capability to offer remote and autonomous operation. With the previous requirements in mind, the authors have proposed and validated a new electrohydraulic steering technology that offers energy efficiency improvement, increased productivity, enhanced safety, and adaptability to operating conditions. In this paper, the authors investigate the new steering technology's capacity to support remote operation and demonstrate it on a compact wheel loader, which can be remotely controlled without an operator present behind the steering wheel. This result establishes the new steer-by-wire technology's capability to enable full autonomous operation as well.

A feedback controller bas been developed using robust control techniques to control the sound radiated from turbulent flow driven plates. The control design methodology uses frequency domain loop shaping techniques. System uncertainty, sound pressure level reductions, and actuator constraints are included in the design process. For the wind noise problem, weighting factors have been included to distinguish between the importance of modes that radiate sound and those that do not radiate. The wind noise controller has been implemented in the quiet wind tunnel facility at the Ray W. Herrick Laboratories at Purdue University. A multiple-input, multiple-output controller using accelerometer feedback and shaker control was able to achieve control up to 1000 Hz. Sound pressure level reductions of as much as 15 dB were achieved at the frequencies of the plates modes. Overall reductions over the 100-1000 Hz band were approximately 5 dB.

An experimental program was conducted to verify the reduction in fuel consumption achievable with aerodynamic improvements to intercity buses. Wind tunnel model tests were used to develop effective aerodynamic improvements and full-scale road tests to validate the results. Greyhound Lines coach models MC-7 and MC-8 were tested with head- and crosswinds. Aerodynamic drag of the MC-7 was reduced 17 percent at zero yaw. Drag of the MC-8 initially was higher; it was reduced 27 percent at zero yaw by the best fairing. Both low-drag configurations were less sensitive to crosswinds than the original models; significant drag reduction was maintained to 15 degrees yaw angle. Fuel consumption measurements made with aerodynamic fairings installed on an MC-7 showed that the low-drag bus used 11.7 percent less fuel at a steady 55 mph. The cost of the full-scale modifications was estimated at $ 1,500 each for a retrofit kit and no added cost to produce on new vehicles.

NO and soot emissions from Diesel engines are dependent on several parameters related to the engine design and operating conditions. Multidimensional models are increasingly employed to study the effect of these parameters. In this paper, a multidimensional model for flows, sprays and combustion in engines is employed to study the dependence of NO and soot formation and oxidation on injection timing, injection pressure, chamber temperature, EGR and ignition delay, and compare the computed trends with those observed in experimental studies reported in the literature. Computations are carried out in a typical heavy-duty Diesel engine and additional computations in a constant volume chamber are used to clarify the engine results when appropriate. For several parametric changes, the experimentally observed trends are reproduced. However, several limitations are identified. The structure of the computed combusting jet has differences with those suggested from recent experiments.

The renewed interest in electric and hybrid-electric vehicles has been prompted by the drastic rise in oil prices in 2008 and launch of new initiatives by the Federal Government. One of the key issues is to promote the incorporation of electric drivetrain in vehicles at all levels and particularly with emphasis on educational activities to prepare the workforce needed for the near future. Purdue University has been conducting a Grand Prix for over 50 years with Gas-powered Karts. In April 2010, an annual event was initiated to hold an EV Grand Prix where 17 EV Karts participated in the competition. Four of the participating teams comprised of Purdue students in a new graduate course for EV design and fabrication. Using the basic framework of the gas-powered Kart, an electric version was developed as a part of this course. Other participants were also provided with the guidelines and design parameters developed for the course and competition.

The mobility modeling technique is applied to the structure-borne noise path through a vehicle suspension. The model is developed using measured FRF data taken on the isolated components of the suspension and body structure of a midsize sedan. Several important modeling issues of suspensions are resolved. It was determined that multiple degrees of freedom are required to model the coupling at joints between the suspension and body structure. The investigation also demonstrated that bushings should not be included in the measurements used to develop these models and should be added later using simplified bushing parameters. The importance of transfer mobility information between the various suspension attachments was also investigated. The agreement between the mobility model predictions and the measured FRF data for the overall system is better than similar data published in the literature to date.

Energy budgets for future Controlled Ecological Life-Support Systems (CELSS) must balance not only with respect to primary productivity (i.e., photosynthesis) vs. utilization steps (human maintenance plus preparative and recycling processes), but also with respect to necessary and desired nonlife-support activities of crews (e.g., exploration, research). Present objectives of the NSCORT program at Purdue University include identification of critical paths for biomass conversion to desired forms with energetics and rate-constant properties that are compatible with life-support sustainability within a CELSS. Physico-chemical recycling systems working in conjunction with bioregenerative ones likely will be required to keep time constants of critical processes within reasonable limits.

A unique concept for a multi-body test rig enabling the simulation of longitudinal, steering and vertical dynamics was developed at the Institute for Mechatronic Systems (IMS) at TU Darmstadt. A prototype of this IMS test rig is currently being built. In conjunction with the IMS test rig, the Vehicle Terrain Performance Laboratory (VTPL) at Virginia Tech further developed a full car, seven degree of freedom (7 DOF) simulation model capable of accurately reproducing measured displacement, pitch, and roll of the vehicle body due to terrain excitation. The results of the 7 DOF car model were used as the reference input to the multi-body IMS test rig model. The goal of the IMS/VTPL joint effort was to determine whether or not a controller for the IMS test rig vertical actuator could accurately reproduce wheel displacements due to different measured terrain constraints.

Grazing flows over open windows or sunroofs may result in “flow buffeting,” i.e. self-sustained flow oscillations at the Helmholtz acoustic resonance frequency of the vehicle. The associated pressure fluctuations may cause passenger fatigue and discomfort. Many solutions have been proposed to solve this problem, including for example leading edge spoilers, trailing edge deflectors, and leading edge flow diffusers. Most of these control devices are “passive” i.e. they do not involve dynamic control systems. Active control methods, which do require dynamic controls, have been implemented with success for different cases of flow instabilities. Previous investigations of the control of flow-excited cavity resonance have used mainly one or more loudspeakers located within the cavity wall. In this study, oscillated spoilers hinged near the leading edge of the cavity orifice were used. Experiments were performed using a cavity installed within the test section wall of a wind tunnel.

The Porous Ceramic Tube - Nutrient Delivery System (PCT-NDS) offers means to control water availability to plants under non-standard gravities. It is hypothesized that control can be obtained by applying suction pressure within the ceramic tubes. The research objectives include verifying the presented control equation for the PCT-NDS under micro-(less than 1 g) and hyper- (greater than 1 g) gravities. Experiments were conducted on a KC-135 subjecting the system to near-zero to 2 g's and to sustained hyper-gravities upto 10 g's using a centrifuge. Results indicated that the water availability can be controlled through applied suction pressure.

The object of the work reported here was to relate the acoustic intensity level measured near the contact patch of a driven tire on a passenger vehicle with the passby noise levels measured at a sideline microphone during coast and cruise conditions. Based on those measurements it was then possible to estimate the tire noise contribution to the passby level measured when the vehicle under test was accelerating. As part of this testing program, data was collected using five vehicles at fourteen passby sites in the United States: in excess of 800 data sets were obtained.

Farmers are a small group, mostly college educated who run multi-million dollar yearly operations. Recent favorable economics has allowed this sector to look at new technology and determine the best way to invest in it. New considerations in the last few years have led to minimum/alternative tillage and planting, site specific farming decisions and small technology groups of farmers. The authors have put together their thoughts and wants which should be evaluated by future suppliers of technology and farm machinery.

It is a time and cost consuming way to physically develop Hybrid Electric Vehicle (HEV) supervisor controller due to the increasing complexity of powertrain system. This study aims to investigate the HEV supervisor controller development process using dSPACE midsize Hardware in the Loop simulation system (HIL) for HEV powertrain control. The prototyping controller was developed on basis of MircoAutoBox II, and an HIL test bench was built on midsize HIL machine for the purpose of verification. The feasibility and capability of HIL were attested by the prototyping control strategy and fault modes simulation. The proposed approach was demonstrated its effectiveness and applicability to HEV supervisor controller development.

This article presents a simple methodology that can be used to increase productivity and reduce ergonomic risk in the workplace environment. First, the procedure will be presented and discussed in a step-by-step format. This ergonomic process will be applied and presented as an example from the aviation maintenance workplace.

Two structure-borne and two airborne paths were measured on 99 “identical” Isuzu RODEOs and 57 “identical” Isuzu pickup trucks. Significant effort was made to control measurement variability but not environmental (climate) variations. A record was kept of the tests of a reference vehicle over the variation of environmental factors. The frequency response functions (FRFs) of the reference vehicle varied by approximately 2-4 dB over the frequency range 0-500 Hz for the structure-borne paths and over 0-1000 Hz for the airborne paths due to measurement and environmental variations. The FRFs of the fleet varied by as much as 5-10 dB over the same frequency range. In this paper, the vehicle tests are described. The reference and the fleet data are shown in raw form. Reduced data and implications of the results are also discussed.

A noise source identification technique for the analysis of thermal systems is presented. The proposed method uses transient spectral sound data to assist in determining the source of sound radiation by tracking the variation of the frequency of tones during transient thermal loading (i.e., thermal system warm-up). By considering the temperature dependence of the modulus of elasticity (Young's modulus) it can be shown that structure related tones will decrease in frequency during warm-up. Tones due to propagation of sound in many fluids (i.e., gases and water) will increase in frequency during warm-up due to the temperature dependence of the speed of sound. The analysis method is demonstrated by identifying the source of several noise tones for a pulse combustion furnace.

Numerical simulations are performed to investigate noise generated by flow in automotive HVAC ducts. A hybrid computational method for analyzing flow noise is applied: Large Eddy Simulation (LES) for predicting flow fields and Multi-domain boundary element method for predicting acoustic propagation. LES gives time-resolved solutions of flow velocity and pressure fields. By applying the acoustic analogy theory, the unsteady flow parameters are translated into sound source in evaluating the acoustic propagation. The computational result shows the noise caused by the HVAC ducts is strong. The noise is of broadband with a peak value at 370Hz. A major contribution of the noise generation is from the center ducts. Two design modifications of the center ducts are explored to regulate the flow structures with the ducts for reducing noise generation. Test results demonstrate the effectiveness of the modifications.