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The primary advantage of an Adaptive Wall wind tunnel is that the test section walls and ceiling are contoured to closely approximate the ‘open road' flowfield around the test vehicle. This reproduction of the open road flowfield then results in aerodynamic forces and moments on the test vehicle that are consistent with actual open road forces and moments. Aerodynamic data measured in the adaptive wall test section do not require blockage corrections for adjusting the data to open road results. Extensive full scale experiments, published scale model studies, and Computational Fluid Dynamics (CFD) studies have verified the simulation capability of adaptive wall technology. For the CFD study described here, high-downforce, open-wheel race cars were studied. The numerical simulations with a race car in an Adaptive Wall Test Section (AWTS) wind tunnel are compared with simulations in ‘free air' condition and in a closed wall test section.

This paper discusses the characteristic flow field of the new Honda FIT/Jazz as determined from the aerodynamic development process, and introduces the technique that reduced aerodynamic drag in a full model change. The new FIT was the first model to take full advantage of the Flow Analysis Simulation tool (FAST), our in-house CFD system, in its development. The FAST system performs aerodynamic simulation by automatically linking the exterior surface design with a predefined platform layout. This allows engineers to run calculations efficiently, and the results can be shared among vehicle stylists and aerodynamicists. Optimization of the exterior design gives the new FIT a moderate pressure peak at the front bumper corner as compared to the previous model, resulting in a smaller pressure difference between the side and underbody.

An aerodynamic styling evaluation system employed at an early automotive development stage was constructed. The system based on CFD consists of exterior model morphing, computational mesh generation, flow calculation and result analysis, and the process is automatically and successively executed by process automation software. Response surfaces and a parallel coordinates chart output by the system allow users to find a well-balanced exterior form, in terms of aerodynamics and exterior styling, in a wide design space which are often arduous to be obtained by a conventional CAE manner and scale model wind tunnel testing. The system was designed so that 5-parameter study is completed within approximately two days, and consequently, has been widely applied to actual exterior styling development. An application for a hatchback vehicle is also introduced as an actual example.

This paper describes the evaluation of flow characteristics inside a model engine cylinder using particle image velocimetry (PIV), laser Doppler anemometry (LDA), and numerical simulation by Partial Cells in Cartesian coordinate (PCC) method. The main goal of the study is to clarify the differences in the velocity characteristics obtained by these methods. The model engine head has a four-valve system. Single- and dual- valve opening conditions of the model engine head were tested by a steady flow test rig. The flow structures were completely different for these valve opening conditions. The mean velocities and their distributions obtained by the three methods show satisfactory agreement. However, there were differences in the turbulence intensities under several conditions and measuring positions. Taylor's hypothesis in the integral length scale of turbulence was also compared with single LDA and PIV measurements.

This paper investigates the aerodynamic simulation accuracy of several types of wind tunnel test sections. Computational simulations were performed with a closed wheel race car in an 11.0 m2 adaptive wall, a 16.8 m2 open jet, and a 29.7 m2 slotted wall test section, corresponding to model blockage ratios of 20.9%, 13.7%, and 7.7%, respectively. These are compared to a simulation performed in a nearly interference-free condition having a blockage ratio of 0.05%, which for practical purposes of comparison, is considered a free air condition. The results demonstrate that the adaptive wall most closely simulates the free air condition without the need for interference corrections. In addition to this advantage, the significantly smaller size of the adaptive wall test section offers lower capital and operating costs.

Gas shielded metal arc welding is generally applied to automobile chassis parts. However, the weld parts with the E-coat show poor corrosion resistance. Therefore, the corrosion mechanism of the weld parts was investigated. The results found two reasons why the weld parts corroded faster than the non weld parts:(1)inadequate phosphating (2)defects in the E-coat. After detailed investigation, it was clarified that the major cause of poor corrosion resistance was the defects in the E-coat caused by slags formed on the surface of the weld bead. Therefore the amount of slag has to be decreased to improve the corrosion resistance. The effect of shielding gas composition on the amount of slag was then investigated. In the case of Ar and oxidizing gas mixture, the corrosion resistance improved as the oxidizing gas content decreased. This was due to the reduction of slags.

New supplier / manufacturer relationship are necessary to produce products quickly, cost-effectively, and with features expected by the customer. However, the need for a new relationship is not universally accepted and endorsed. Resistance can be minimized through supplier self-assessment (such as Ford Motor Company's web-based instruments), management initiatives, and incentives. Trust and sharing are hallmarks. This strategy requires a new workplace paradigm affecting culture and people issues. Teams, extend across companies, share ideas and innovations. Decisions need to be mutually beneficial and the long-term value, for supplier and manufacturer, needs to be considered.

Turbine housings in car engine turbochargers, which use costly stainless steel castings, account for nearly 50% of the parts cost of a turbocharger. They are also the component which controls the competitiveness of the turbocharger, in terms of both function and cost. In this research, focusing on thermal fatigue resistance which is one of the main functions demanded of a turbine housing, achieving reduction in wall thickness while securing sufficient thermal fatigue resistance, it is possible to reduce the amount of material used in the turbine housing and aimed for cost reduction. Therefore, we built a method to quantitatively predict, using 3D FEM, the lifespan from the initiation of thermal fatigue cracking to the formation of a penetrating crack which leads to gas leakage.

There are several all-aluminum cylinder blocks. A typical example is a mono-block cylinder of alusil alloy produced by low pressure die casting. This material's resistance to abrasion and seizure, however, is not satisfactory for motorcycle; in addition, long processing time is another disadvantage. To cope with these problems, the authors developed a light and highly productive all-aluminum cylinder block with a cast-in liner through die casting. The liner is made from powder metallurgy composite (PMC) with 3 to 5 % alumina and 0.5 to 3 % of graphite additives. The PMC reconciles abrasion resistance and machinability. The hardness deterioration of the composite due to the heat at die casting is avoided by using heat-resistant rapidly-solidified powders, made from an aluminum-silecon-iron alloy, for the matrix.

In general, welding of high-pressure die casting (DC) parts has been difficult due to gases trapped in the castings. This is a result of the high-speed turbulent flow condition of the DC process. These gases are liberated during welding and produce porosity in the weld joint. The Author had found the range where an enough welding quality was obtained without great drop in castability to the middle of the laminar flow and turbulent flow. This range has been defined as the transition zone. Moreover high strength Al-Mg-Ni alloy was developed by non-heat-treatment. The Transition Flow Filling Method(TFFM) has been developed, that can not only reduce the amount of trapped gases but also is applicable to standard high pressure die casting equipment. With this method, high quality DC parts can be produced that are weldable, strong and have high toughness.

Amidst of the recent concerns on depletion of natural resources, a new heat resistant titanium alloy has been developed using the minimum amount of rare metals. Using Ti-811 as a basis and modifying the alloy composition to Ti-7Al-2Mo-0.2Si-0.15C-0.2Nb, the mechanical property, the creep resistance and the oxidation resistance at high temperatures are improved. At the same time, with the β transformation point shifted to a higher temperature, the hot formability is also improved. The newly developed alloy has made it possible to expand the application of titanium material to exhaust valves in reciprocating engines.

Wind Tunnel 8 of the Driveability Test Facility (DTF), which achieved full operational status in 2001, is designed to provide full powertrain, aerodynamic, and aero-acoustic test capabilities for automotive product development. In order for it to be fully integrated into product testing, the Ford product engineering community needed to correlate the facility. The major objective of the correlation is quantitative aerodynamic correlation, which will be achieved when aerodynamic coefficients measured in Wind Tunnel 8 can be understood in the context of aerodynamic measurements obtained in other wind tunnels that Ford has used for product testing. The motivation for this study is the aerodynamic interference that is present in all wind tunnels. Aerodynamic interference is the deviation between the true result—which is difficult to determine—and the actual result obtained from the wind tunnel.

Conventional HEV motors use neodymium magnets with added heavy rare earths, to realize high output and size reduction. However, deposits of heavy rare earths such as Dysprosium (Dy) and Terbium (Tb) are unevenly distributed, so it is important to reduce the amount used, because of supply issue and material cost. In this paper, the application of a heavy rare earth-free magnet is considered on the new motor for a two-motor hybrid system. Compared to conventional neodymium magnets, heavy rare earth free magnets tend to have low coercivity. Also, heavy rare earth-free magnet have low thermal durability, so it is not easy to apply them to motors for a two-motor hybrid system, which requires high output and small size. The motor requires twice as much torque and six times output than one-motor hybrid system. Increase demagnetization resistance and magnet cooling performance is studied by development of the new motor.

A toroidal variator is the core part of an advanced Continuously Variable Transmission (CVT) design. Knowing its behavior and internal forces is key to defining the operational conditions of the transmission. To maintain a steady-state speed ratio, or to accurately and efficiently move between speed ratios, optimal trunnion control force is required. The unique design of the toroidal CVT makes the design very sensitive to trunnion positioning and force transients. Analytical understanding of the mechanism response is critical to toroidal variator controller design. A critical feature of the toroidal CVT simulation is representation of the friction forces in the disk-roller contact. This effect is important to the mechanism torque capacity and efficiency.

In the early stages of aerodynamic development of commercial vehicles, the aerodynamic concept is balanced with the design concept using CFD. Since this development determines the aerodynamic potential of the vehicle, CFD with high accuracy is needed. To improve its accuracy, spatial resolution of CFD should be based on flow phenomenon. For this purpose, to compare aerodynamic force, pressure profile and velocity vector map derived from CFD with experimental data is important, but there are some difficulties to obtain pressure profile and velocity vector map for actual vehicles. At the point of pressure measurement for vehicles, installation of pressure taps to the surface of vehicle, i.e., fuel tank and battery, is a problem. A new measurement method developed in this study enables measurement of surface pressure of any desired points. Also, the flexibility of its shape and measuring point makes the installation a lot easier than the conventional pressure measurement method.

A new nitriding technology and material technology have been developed to increase the strength of microalloyed gears. The developed nitriding technology makes it possible to freely select the phase composition of the nitride compound layer by controlling the treatment atmosphere. The treatment environment is controlled to exclude sources of supply of [C], and H2 is applied as the carrier gas. This has made it possible to control the forward reaction that decomposes NH3, helping to enable the stable precipitation of γ′-phase, which offers excellent peeling resistance. A material optimized for the new nitriding technology was also developed. The new material is a low-carbon alloy steel that makes it possible to minimize the difference in hardness between the compound layer and the substrate directly below it, and is resistant to decline in internal hardness due to aging precipitation in the temperature range used in the nitriding treatment.

An air-dam spoiler is commonly used to reduce aerodynamic drag in production vehicles. However, it inexplicably tends to show different performances between wind tunnel and coast-down tests. Neither the reason nor the mechanism has been clarified. We previously reported that an air-dam spoiler contributed to a change in the wake structure behind a vehicle. In this study, to clarify the mechanism, we investigated the coefficient of aerodynamic drag CD reduction effect, wake structure, and underflow under different boundary layer conditions by conducting wind tunnel tests with a rolling road system and constant speed on-road tests. We found that the air-dam spoiler changed the wake structure by deceleration of the underflow under stationary floor conditions. Accordingly, the base pressure was recovered by approximately 30% and, the CD value reduction effect was approximately 10%.

In this research, a new wire material made using surface-reforming heat treatment was developed in order to enhance the corrosion fatigue resistance of suspension springs. The aim of surface reforming is to improve hydrogen embrittlement characteristics through grain refinement and to improve crack propagation resistance by partial softening of hardness. The grain refinement method used an α'→γ reversed transformation by rapid short-term heating in repeated induction heating and quenching (R-IHQ) to refine the crystal grain size of SAE 9254 steel spring wire to 4 μm or less. In order to simultaneously improve the fatigue crack propagation characteristics, the possibility of reducing the hardness immediately below the spring surface layer was also examined. By applying contour hardening in the second IHQ cycle, a heat affected zone (HAZ) is obtained immediately below the surface.

The change in the aerodynamic lift force (henceforth CL) by heave motion is discussed in this paper in order to clarify the effect of aerodynamic characteristics on the vehicle dynamic performance. We considered that phenomenon in actual car running at 160km/h and 1Hz heave frequency. Using a towing tank to change its water from the air to the working fluid to more easily observe this phenomenon. That makes possible to observe the same phenomenon with reduced velocity and small models under same Strouhal number condition. This method can be reducing vehicle speed to 3m/s (1/15 actual) and frequency to 0.2Hz (1/5 actual) in case using 40% scaled model. The results of these tests showed that unsteady CL is proportional to heave motion. These results showed the proportional relationship between unsteady CL and heave motion. The formularization of unsteady CL made it possible to introduce shape coefficients to vehicle dynamics simulations as functions of heave velocity.

Experimental and computational simulation techniques were concurrently employed throughout the aerodynamic development of the NASCAR Dodge Intrepid R/T in order to achieve a greater understanding of the complex flow fields involved. With less than 500 days to design, understand, and build a competitive vehicle, the development team utilized a closed loop approach to testing. Scale wind tunnel models and Computational Fluid Dynamics (CFD) were used to identify program direction and to speed the development cycle versus the traditional process of full scale testing. This paper will detail the process and application of both the experimental and computational techniques used in the aerodynamic development of the Intrepid R/T race vehicle, primarily focusing on the earlier stages that led to its competition introduction at the start of the 2001 season.