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Aerodynamic had played a primary role in high performance car since the late 1960s, when introduction of the first inverted wings appeared in some formulas. Race car aerodynamic optimisation is one of the most important reason behind the car performance. Moreover, for high performance car using naturally aspired engine, car aerodynamic has a strong influence also on engine performance by its influence on the engine airbox. To improve engine performance, a detailed fluid dynamic analysis of the car/airbox interaction is highly recommended. To design an airbox geometry, a wide range of aspects must be considered because its geometry influences both car chassis design and whole car aerodynamic efficiency. To study the unsteady fluid dynamic phenomena inside an airbox, numerical approach could be considered as the best way to reach a complete integration between chassis, car aerodynamic design, and airbox design.

A realistic modeling of the wall heat transfer is essential for an accurate analysis and simulation of the working cycle of internal combustion engines. Empirical heat transfer formulations still dominate the application in engine process simulations because of their simplicity. However, experiments have shown that existing correlations do not provide satisfactory results for all the possible operation modes of hydrogen internal combustion engines. This paper describes the application of a flow field-based heat transfer model according to Schubert et al. [1]. The models strength is a more realistic description of the required characteristic velocity; considering the influence of the injection on the global turbulence and on the in-cylinder flow field results in a better prediction of the wall heat transfer during the compression stroke and for operations with multiple injections. Further an empirical hypothesis on the turbulence generation during combustion is presented.

Ford Motor Company is introducing “EcoBoost” gasoline turbocharged direct injection (GTDI) engine technology in the 2010 Lincoln MKS. A logical enhancement of EcoBoost technology is the use of E85 for knock mitigation. The subject of this paper is the optimal use of E85 by using two fuel systems in the same EcoBoost engine: port fuel injection (PFI) of gasoline and direct injection (DI) of E85. Gasoline PFI is used for starting and light-medium load operation, while E85 DI is used only as required during high load operation to avoid knock. Direct injection of E85 (a commercially available blend of ∼85% ethanol and ∼15% gasoline) is extremely effective in suppressing knock, due to ethanol's high inherent octane and its high heat of vaporization, which results in substantial cooling of the charge. As a result, the compression ratio (CR) can be increased and higher boost levels can be used.

In this work, a quasi-dimensional, multi-zone combustion model is analytically presented, for the prediction of performance and nitric oxide (NO) emissions of a homogeneous charge spark ignition (SI) engine, fueled with biogas-H2 blends of variable composition. The combustion model is incorporated into a closed cycle simulation code, which is also fully described. Combustion is modeled on the basis of turbulent entrainment theory and flame stretch concepts. In this context, the entrainment speed, by which unburned gas enters the flame region, is simulated by the turbulent burning velocity of a flamelet model. A flame stretch submodel is also included, in order to assess the flame response on the combined effects of curvature, turbulent strain and nonunity Lewis number mixture. As far as the burned gas is concerned, this is treated using a multi-zone thermodynamic formulation, to account for the spatial distribution of temperature and NO concentration inside the burned volume.

A numerical investigation on a series of Diesel spray experiments in constant-volume vessels is proposed. Non reacting conditions were used to assess the spray models and to determine the grid size required to correctly predict the fuel-air mixture formation process. To this end, not only computed liquid and vapor penetrations were compared with experimental data, but also a detailed comparison between computed and experimental mixture fraction distributions was performed at different distances from the injector. Grid dependency was reduced by introducing an Adaptive Local Mesh Refinement technique (ALMR) with an arbitrary level of refinement. Once the capabilities of the current implemented spray models have been assessed, reacting conditions at different ambient densities and temperatures were considered. A Perfectly Stirred Reactor (PSR) combustion model, based on a direct integration of complex chemistry mechanisms over a homogenous cell, was adopted.

The acoustic impedance of a circular, confined, side branch orifice subjected to grazing flow is studied. Two geometries are tested. In both geometries, the side branch dimension is of the same order as that of the main duct. The system is viewed as an acoustic three-port, whose passive properties are described by a system matrix. The impedance is studied with the acoustic field incident at different ports, which is shown to influence the results significantly. When excited from the leading edge or from the side branch, an interaction of the hydrodynamic and acoustic fields is triggered, while excitation from the trailing edge does not trigger such an interaction. For both the resistance and the reactance (here expressed as an end correction) the results vary in the three possible excitation cases. In the quasi-stationary limit the resistance is given by a loss coefficient times the Mach number, and the end correction collapses to a single value.

Herschel and Planck satellites have recently undergone the thermal vacuum and thermal balance (TVTB) test which was performed in the ESA-ESTEC Large Space Simulator for Herschel and in Centre Spatial de Liège (CSL) for Planck. One of the specific targets of the Herschel test was the verification of the thermal stability of two HIFI units (required to be better than 3.10−4 °C/s) and of the Star Tracker mounting plate (required to be better than 2.5.10−3 °C/s), with particular attention on the performance of the relevant feedback control loops. Control system design and model predictions are presented and compared against the test results. Further discussion on the requirement verification is provided.

Long-term exposure to the space radiation environment poses deleterious effects to both humans and space systems. The major sources of the radiation effects come from high energy galactic cosmic radiation and solar proton events. In this paper we investigate the radiation-mitigation properties of several shielding materials for possible use in spacecraft design, surface habitats, surface rovers, spacesuits, and temporary shelters. A discussion of the space radiation environment is presented in detail. Parametric radiation shielding analyses are presented using the NASA HZETRN 2005 code and are compared with ground-based experimental test results using the Loma Linda University Proton Therapy facility.

JSC-1A lunar simulant has been applied to AZ93 and AgFEP thermal control surfaces on aluminum substrates in a simulated lunar environment. The temperature of these surfaces was monitored as they were heated with a solar simulator using varying angles of incidence and cooled in a 30 K coldbox. Thermal modeling was used to determine the solar absorptivity (a) and infrared emissivity (e) of the thermal control surfaces in both their clean and dusted states. It was found that even a sub-monolayer of dust can significantly raise the α of either type of surface. A full monolayer can increase the α/ε ratio by a factor of 3–4 over a clean surface. Little angular dependence of the α of pristine thermal control surfaces for both AZ93 and AgFEP was observed, at least until 30° from the surface. The dusted surfaces showed the most angular dependence of α when the incidence angle was in the range of 25° to 35°.

The investigation of the flow through the metering section of hydraulic components plays a fundamental role in the design and optimization processes. In this paper the flow through a closed center directional control valve for load -sensing application is studied by means of a multidimensional CFD approach. In the analysis, an open source fluid-dynamics code is used and both cavitation and turbulence are accounted for in the modeling. A cavitation model based on a barotropic equation of state and homogeneous equilibrium assumption, including gas absorption and dissolution in the liquid medium, is adopted and coupled to a two equation turbulence approach. Both direct and inverse flows through the metering section of the control valve are investigated, and the differences in terms of fluid - dynamics behavior are addressed In particular, the discharge coefficient, the recirculating regions, the flow acceleration angle and the pressure and velocity fields are investigated and compared.

The cost of human natural language translation of Service Information, Assembly Instructions, Training Materials, Operator Manuals and other similar documents is a major expense for manufacturers. One translation avoidance method involves replacing most of a document’s text with still and/or animated graphics. While the graphics with minimum text concept has savings potential, clarity of communication must be maintained for widespread application of this technique. The necessary clarity should be achieved if standards are established for the symbols and graphical conventions used. This paper provides an example of a repair procedure documented using the graphics with minimum text paradigm, describes many of the anticipated standards and provides an update on the progress towards achieving a standard development project.

Brake judder is about oscillations excited by brake application, which are generated in the contact area between brake pad and brake disc and are transmitted by the elements of the suspension to body and steering system. The driver perceives these perturbations as brake pedal pulsations, steering wheel rotational and body vibrations. The evaluation of a suspension concerning brake judder often takes place for the first time in road tests, since established simulation processes with a high significance concerning ride comfort are missing. At such a late moment necessary modifications in the development process are only hardly possible and very expensive. For avoiding brake judder a systematic development process is needed for brake and suspension. Each one can separately be improved in measurably borders so that their assembly is free of cold brake judder. The present paper shows appropriate test and simulation methods to achieve this.

Scope of the DRESS project is to research, develop and validate a distributed and redundant electrical steering system technology for an aircraft nose landing gear. The new system aims to: • reduce system weight at aircraft level, replacing the current hydraulic actuation system with an electric one. • improve aircraft safety, achieving higher system redundancy levels compared to the current technology capabilities. This paper presents an outline of different activities occurring in the DRESS project and also shows preliminary results of the new system performance.

Patents granted recently to Mr. Rode have changed the industry capability to adjust and verify wheel-end bearings on trucks. Until now it was believed1 that there was nothing available to confirm or verify the most desirable settings of preload on these bearings. The new, breakthrough invention is a tool and spindle-locking nut that permit quick and accurate wheel bearing adjustment by utilizing direct reading force measurement. Bearings can be set to either SAE recommended preloads or specific endplay settings. The author has been working on bearing adjustment methods for industrial applications for over forty years, and considers these inventions to be his most important breakthrough for solving this elusive bearing adjustment problem. Consistent wheel bearing preload adjustment was not possible before, even though it was widely known to achieve the best wheel performance as noted in SAE specification J2535 and re-affirmed in 2006 by the SAE Truck and Bus Wheel Subcommittee.

A heavy truck wind tunnel test program is currently underway at the Langley Full Scale Tunnel (LFST). Seven passive drag reducing device configurations have been evaluated on a heavy truck model with the objective of understanding the practical limits to drag reduction achievable on a modern tractor trailer through add-on devices. The configurations tested include side skirts of varying length, a full gap seal, and tapered rear panels. All configurations were evaluated over a nominal 15 degree yaw sweep to establish wind averaged drag coefficients over a broad speed range using SAE J1252. The tests were conducted by first quantifying the benefit of each individual treatment and finally looking at the combined benefit of an ideal fully treated vehicle. Results show a maximum achievable gain in wind averaged drag coefficient (65 mph) of about 31 percent for the modern conventional-cab tractor-trailer.

The timing and associated levels of braking between initial brake pedal application and actual maximum braking at the wheels for a tractor-semitrailer are important parameters in understanding vehicle performance and response. This paper presents detailed brake timing information obtained from full scale instrumented testing of a tractor-semitrailer under various conditions of load and speed. Brake timing at steer, drive and semitrailer brake positions is analyzed for each of the tested conditions. The study further seeks to compare the full scale test data to predicted response from detailed heavy truck computer vehicle dynamics simulation models available in commercial software packages in order to validate the model's brake timing parameters. The brake timing data was collected during several days of full scale instrumented testing of a tractor-semitrailer performed at the Transportation Research Center, in East Liberty, Ohio.

A driving simulator capable of duplicating the critical sensations incurred during a spin, or when a driver is engaged in drift cornering, was constructed by Mitsubishi Heavy Industries, Ltd., and Hiromichi Nozaki of Kogakuin University. Specifically, the simulator allows independent movement along three degrees of freedom and is capable of exhibiting extreme yaw and lateral acceleration behaviors. Utilizing this simulator, the control characteristics of drift cornering have become better understood. For example, after a J-turn behavior experiment involving yaw angle velocity at the moment when the drivers attention transitions to resuming straight ahead driving, it is now understood that there are major changes in driver behavior in circumstances when simulator motions are turned off, when only lateral acceleration motion is applied, when only yaw motion is applied, and when combined motions (yaw + lateral acceleration) are applied.

Requirements analysis for aircraft simulators is often driven by photographs and videos of the actual aircraft. An engineer may gather and organize hundreds or even thousands of source photos of various instruments and devices unique to the aircraft. Managing all of this source information and referencing it to generate software requirements can be challenging and time-consuming. This paper explores Content Based Image Retrieval (CBIR) techniques to automatically process and search those images to generate basic requirements and to facilitate reuse. An unsupervised clustering algorithm groups source images based on minimal user input. Images processed in this way can also be queried by image similarity, thereby allowing project managers to find common source material among projects. The effectiveness of these techniques is demonstrated on an example cockpit.

A series hydraulic hybrid concept (SHHV) has been explored as a potential pathway to an ultra-efficient city vehicle. Intended markets would be congested metropolitan areas, particularly in developing countries. The target fuel economy was ~100 mpg or 2.4 l/100km in city driving. Such an ambitious target requires multiple measures, i.e. low mass, favorable aerodynamics and ultra-efficient powertrain. The series hydraulic hybrid powertrain has been designed and analyzed for the selected light and aerodynamic platform with the expectation that (i) series configuration will maximize opportunities for regeneration and optimization of engine operation, (ii) inherent high power density of hydraulic propulsion and storage components will yield small, low-cost components, and (iii) high efficiency and high power limits for accumulator charging/discharging will enable very effective regeneration.

Today, high performance race car efficiency is based on a very fine equilibrium between aerodynamic efficiency, engine performance, and chassis behaviour. In particular, from the engine point of view, one way to increase the performance is to increase its volumetric efficiency. The aim of this paper is to present the application of the Large Eddy Simulation (LES) approach for the fluid dynamic analysis of a high performance race car airbox geometry. For a naturally aspired engine, the fluid dynamic optimisation of the airbox geometry means to optimise the energy conversion (from dynamic to static pressure) inside the airbox itself, therefore to increase the flow energy on the engine trumpet sections. The LES approach seems to be the best candidate to investigate such a flow since flow unsteadiness are expected to affect airbox efficiency in terms of pressure recovery. The airbox simulations were performed by using the commercial CFD code Fluent v6.3.