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It is well understood that conditions encountered during racetrack driving are amongst the most severe to which vehicle braking systems can be subjected. High braking pressure is combined with enormous energy input and high temperatures for multiple braking events. Brake fade, degradation of brake pedal feel, and brake lining taper/overall wear are common results of racetrack usage. This paper focuses on how racetrack and high energy driving-type conditioning affects the performance of the brake caliper - in particular, its ability to maintain an even pressure distribution at all of its interfaces (pad to rotor, piston to pad backing plate, and housing to pad backing plate).

The dischargeable heat output and the cooling drag of motor vehicles are largely determined by the radiator size and the cooling air mass flow rate. In the present work, the effect of varying the radiator size on the cooling air requirement and the cooling drag of a motor vehicle is investigated. The starting point is the assumption that the transferred cooling power remains constant when the radiator size is changed. Based on the physical principles of heat and momentum transfer, a simple mathematical representation of the relationship between the radiator size, cooling air demand, and cooling drag is developed for this case, enabling an overall representation in clear diagrams. The results are validated by an experimental example from the literature. In addition, the application of the new equations is demonstrated in a real vehicle project where the aerothermodynamic challenge was a reduction in radiator size.

The turbulence environment in the real world is known to be significantly different to that found in a typical automotive wind tunnel. Various studies have shown that raising the level of freestream turbulence has an effect on the forces on generic bluff bodies and real vehicles. Previous work at Loughborough has shown a significant effect of raised freestream turbulence on edge radius optimisation using measurements of forces and moments, and in this paper the underlying changes in the flowfield are investigated using PIV. Results are presented of the flowfield around the leading edge radius of the generic bluff body used in the previous work. The effect of changing the Reynolds number is investigated in the clean tunnel (0.2% turbulence), and it is found that, when the radius is small, there is a significant separation that persists up to a high speed, and then abruptly collapses.

A study was undertaken to establish what happens to engine emissions, and to turbocharger and injection pressure requirements, as the specific output is raised. For any given engine package, increasing specific output increases injection pressures while reducing air/fuel ratios. Thus, if the highly rated engine must satisfy the same design constraints, then raising the engine operating torque by only 10% resulted in more than 30% increase in total particulates! However, the same emission levels may be maintained if increases in specific output are accompanied by changes to engine design so as to maintain the air-fuel mixing parameters, specifically air/fuel ratio and injection pressures, throughout the entire engine operating conditions.

Vegetable oils are very attractive as alternative fuels in view of closed carbon circulation in atmosphere and what follows the restriction of the greenhouse effect. Rape oil is one of plant derived fuels which use as a diesel fuel is thoroughly studied in many countries (Germany, Austria, France). The results of research in which particulate matter emission was measured in the 13-Mode Test Procedure, for rape oil - diesel oil mixtures with 10%, 15%, 20%, 30% and 40% rape oil contents, and comparatively for diesel oil, have been presented in the paper. AD 3.152 DI engine was the object of investigation. The research was conducted in conformity with the ECE R49 standard.

Much research has been carried out in recent years to estimate perceived comfort levels for passengers in motor vehicles. This interest is in part due to the introduction of specific provisions (e.g. Law 81/08 in Italy). Another factor is the increased interest and attention of customers. These studies have concentrated in large part on driver position. However, this work describes an application of postural analysis of with results obtained via data acquired during the interaction between the passenger and the dashboard. Tests were carried out in the Virtual Reality Laboratory (VR Lab) at the University of Salerno using a physical mock-up of a passenger car seat involving a fully reconfigurable seating buck. The interior of a FIAT Grande Punto, MY 2013, was configured by setting the seating-buck parameters. Twenty participants were asked to sit in the car seat with their shoulders against the seatback. They were then asked to reach each of the dashboard buttons.

The performance characteristic of a torque converter strongly depends on the reactor blade geometry, which directly affects its torque ratio and input capacity factor. We investigated the effect of the reactor blade geometry with varying thickness ratios and scroll angles on the performance of a torque converter. Using a previously developed design software, TorconMaster®, several reactor blades were newly generated with varying thickness ratios and scroll angles. Their performance characteristics were analyzed by numerical analysis. The present numerical analysis considered the details of the full three-dimensional, viscous and turbulent flow field within the automotive torque converter adopting a mixing plane model and showed good agreement with experimental results. The numerical results provided refined relationships between geometry and performance.

The risk of sustaining injury in rear impact collisions is correlated to collision severity as well as other factors such as restraint usage. The most recent National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) data available (1997 to 2011) were analyzed to identify accidents involving passenger vehicles that have experienced an impact with a principal direction of force (PDOF) between 5:00 and 7:00, indicating a rear impact collision. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants who were at least sixteen years old and were seated in the outboard seating positions of the front row. These data were further analyzed to determine injury risk based on resultant delta-V and restraint system use. Each body region (head, spine, thorax, abdomen, upper extremity, and lower extremity) was considered separately.

Future Generation Intelligent Transport Systems (FGITS) will likely implement solutions to increase traffic density and thus throughput on existing infrastructures. Platooning (e.g. the close coupling of vehicles) may be a prominent feature of this solution, placing an understanding of near wake flows paramount to the FGITS case. However the notion of vehicles spaced at greater intervals is not only more commonly associated with present day conditions; it is furthermore characteristic of mixed-fleet conditions. These are likely to span the significant era between present day and complete FGITS fleets. Thus, far wake flows are similarly relevant. Near and far wake analysis of a variable geometry Ahmed Model (a research form able to replicate structured wakes pertinent to practical vehicle flows) is used to explore relevant generic flow structures.

A research program was conducted to determine the effects of thermal barriers in the combustion chamber on emissions and combustion of a direct-injection diesel engine operated on selected alternate fuels. Steady-state exhaust emissions, cranking characteristics and combustion data of a baseline water-cooled engine were compared with those of a heat insulated uncooled engine with both engines operated on a reference fuel and two alternate fuels. A high compression ratio water-cooled engine with intake air heating was also included in the study. Operating the baseline water-cooled engine on alternate fuel generally raised the level of exhaust emissions. In addition, ignition delay and the rates and relative amounts of premixed and diffusion burning were significantly altered when the baseline water-cooled engine was tested with alternate fuels.

An experimental investigation has been carried out to compare the indicated performance and heat release characteristics of a DI diesel engine at compression ratios of 18.4:1 and 15.4:1. The compression ratio was changed by modifying the piston bowl volume; the bore and stroke were unchanged, and the swept volume was nominally 500cc. The engine is a single cylinder variant of modern design which meets Euro 4 emissions requirements. Work output and heat release characteristics for the two compression ratios have been compared at an engine speed of 300 rev/min and test temperatures of 10, -10 and -20°C. A more limited comparison has also been made for higher speeds representative of cold idle at one test temperature (-20°C). The reduction in compression ratio generally produces an increase in peak specific indicated work output at low speeds; this is attributable to a reduction in blowby and heat transfer losses and lower peak rates of heat release increasing cumulative burn.

A Hybrid Electric Vehicle(HEV) has been developed for use in the intercollegiate 1993 and 1994 Hybrid Electric Vehicle Challenges. A conventionally powered vehicle was converted to a series drive hybrid electric vehicle, named AMPhibian II. The AMPhibian is designed to be an economically feasible HEV, for use in near term applications. To accomplish this, all components are based upon existing technology. Regenerative braking is used to improve the range and economy of the hybrid electric vehicle. The design and performance of the vehicle, including the relative benefits of regenerative braking are reported.

The effects of austenite grain size on the bending fatigue crack initiation and fatigue performance of gas carburized, modified 4320 steels were studied. The steels were identical in composition except for phosphorus concentration which ranged between 0.005 and 0.031 wt%. Following the carburizing cycle, specimens were subjected to single and triple reheat treatments of 820°C for 30 minutes to refine the austenite grain structure, and oil quenched and tempered at 150°C. Specimens subjected to bending fatigue were characterized by light metallography to determine microstructure and grain size, X-ray analysis for retained austenite and residual stress measurements, and scanning electron microscopy for examination of fatigue crack initiation and propagation. The surface austenite grain size ranged from 15 μm in the as-carburized condition to 6 and 4 μm diameter grain size for the single and triple reheat conditions, respectively.

In this work, reground post consumer plastic waste was melt blended with reinforcing additives and processed into boards using an extrusion molding process. The additives used were glass fiber, 50% long glass fiber reinforced polypropylene pellets, and polypropylene. Compressive, flexural and nail pullout tests were performed on the extruded plastic composite lumber substitute materials at three temperatures, namely -20°C, 20°C and 50°C. Similar tests were also performed on pressure treated lumber for comparison. In addition, the coefficient of friction of each formulation was evaluated both wet and dry. The results of the study show that additives and fibrous reinforcements can bring the compressive and flexural properties of the commingled plastic waste lumber closer to those of pressure treated lumber.

The subject study presents the results of an investigation into the effects of the level of mesh fineness used on the calculated test vehicle b1-Campbell and CRASH3 A and B stiffness coefficients based upon FMVSS 214D compliance and high-speed lateral NCAP assessment tests. An analytical method is presented based upon a matrix implementation of the existing CRASH3 formulation that allows for the rapid evaluation of all iterations of the equally spaced formulation based on the number of measured crush values present to the front face of the side-impact moving deformable barrier {N: 2 ≤ N ≤ 17}. This formulation accounts for the necessity for aligning the nodes used in the discretization of the direct damage regions of the test vehicle and the moving deformable barrier for the zonal implementation of the force balance method.

This paper presents a study of the effects of a resin soluble thermoplastic preform binder on the Resin Transfer Molding (RTM) process. The focus of the study is the rate of dissolution of the binder in the resin and the associated viscosity changes in the resin. Tests on the rate of binder dissolution from continuous strand glass mats show that after one minute of exposure to styrene, roughly half of the medium solubility binder from Unifilo 750 will dissolve and all of the high solubility binder from Unifilo 101 will dissolve. As the concentration of binder in the resin increases from 0 to 5 wt. percent, the viscosity of a vinyl ester resin increases from 125 cps to 280 cps. The viscosity of the resin has also been monitored in continuous flow experiments through the mats placed in a rectangular plague mold, at different flowrates. In these runs, the viscosity varied from 245 mPa-s to 145 mPa-s when the fill time was 2.2 minutes.

The Restorative Maintenance Program conducted by the Environment Protection Agency in late 1976 and early 1977 provides short test and Federal Test Procedure data on a large fleet of relatively new consumer owned automobiles. The program included testing of 300 vehicles in Chicago, Detroit and Washington, D.C. The vehicles that indicated a need for maintenance were repaired and retested by the FTP and the five short tests being considered by the agency for the Federal warranty regulations. These data are examined by conventional regression and correlation methods, contingency table analysis and maintenance effectiveness criteria. The conclusions of the study indicate that while the mathematical correlation coefficients are quite low for most of the tests, all five tests are effective in identifying vehicles in need of maintenance and significant hydrocarbon and carbon monoxide emissions reductions can be achieved at relative low vehicle failure rates.

The high level of protection afforded by the safety belt has been proved in the past beyond doubt. The results of national and international studies of its effectiveness are given. The possible relative reduction of the frequency of injuries to different parts of the body is pointed out. These reduction quotas are derived by means of direct comparison from equivalent real-life accidents. The effects of a 100% and 85% belt-wearing rate is described for the traffic accident incidence in the Federal Republic of Germany. On the basis of selected study material comprising 200 belted car drivers who were involved in head-on collisions, the injuries to the different parts of the body are presented in relation to the accident severity. In the light of these injuries, technical measures to the car and the belt system are proposed which might effect a further reduction of injuries.

Retrogression heat treatments were developed to improve the formability and mechanical behavior of age-hardenable aluminum wrought products in both the aerospace and automobile industries. The heat treatments can provide an improvement in the flanging and trimming behavior of age-hardenable aluminum sheet alloys. The present paper reviews the effect of retrogression heat treatments on flanging by demonstrating reduced springback and increased flange length; on trimming by showing the elimination of metal slivers; and on shape fixability through a three point deflection test. This work should aid in the development of improved aluminum alloys and modified forming processes to enable the increased use of aluminum sheet products.

This study investigates the isolated effect of rib shape on the mechanical characteristics of ribs subjected to multiple forms of loading. It aims to measure the variation in stiffness due to shape that is seen throughout the population and, in particular, provide a tool for researchers to better understand the influence of shape on resulting stiffness. A previously published six-parameter shape model of the central axis of human ribs was used. It has been shown to accurately model the overall rib path using intrinsic geometric properties such as size, aspect ratio, and skewness, through shapes based on logarithmic spirals with high curvature continuity. In this study the model was fitted to 19,500 ribs from 989 adult female and male CT scans having demographic distributions matching the US adult population. Mechanical loading was simulated through a simplified finite element model aimed at isolating rib shape from other factors influencing mechanical response.