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Internal combustion engines development with increased complexity due to CO2 reduction and emissions regulation, while reducing costs and duration of development projects, makes numerical simulation essential. 1D engine simulation software response for the gas exchange process is sufficiently accurate and quick. However, combustion simulation by Wiebe function is poorly predictive. The objective of this paper is to compare different approaches for 0D Spark Ignition (SI) modeling. Versions of Eddy Burn Up, Fractal and Flame Surface Density (FSD) models have been coded into GT-POWER platform, which connects thermodynamics, gas exchange and combustion sub-models. An initial flame kernel is imposed and then, the flame front propagates spherically in the combustion chamber. Flame surface is tabulated as a function of piston position and flame radius. The modeling of key features of SI combustion such as laminar flame speed and thickness and turbulence was common.

For human beings who have been reared on the earth with its 1 G gravitational field, the condition of weightlessness is a world with which we are unfamiliar. Even if the layout and equipment configuration of a spacecraft designed to compensate for operation under Zero-G conditions, there are some things which are not effective under actual weightless conditions. In the design of a manned spacecraft, it is necessary to accumulate design data on human performance in a weightless condition, then to undertake design evaluations and verification under weightless conditions. In this paper, testing for the purpose of evaluating the effectiveness of Zero-G simulation using neutral buoyancy, conducted first of all in Japan, and recommendations on the equipment and Facilities required to conduct such simulations, are described.

In spite of environmental issues related to cadmium and its electroplating process, electroplated cadmium is still extensively used in the aerospace and defense sectors. This trend is likely to continue especially for high strength steels because cadmium provides the best known corrosion and embrittlement protection for this application. Consequently, the environmental concerns related to the cadmium electroplating have been addressed using an alternative Zero-waste Physical Vapor Deposition (Z-PVD). This method does not use liquids, it recycles cadmium in situ, and is free of hydrogen embrittlement. The Z-PVD process is now in commercial production for the aerospace fasteners. The quality of the coatings has been at least equal to that of the electroplated cadmium.

A zero-dimensional dynamic model was developed in the Matlab/Simulink® environment to predict the behaviour of a variable-displacement lubricating vane pump for internal combustion engine applications. Based on the geometric and kinematic characteristics of the pump, the model allows predictions of the pressure evolution in each chamber of the pump and in the delivery piping, by employing an integrative-derivative approach. Simulation results were compared with experimental data of pressure transducers, which were fitted along the periphery of the pump case and in the delivery channel. The analysis of the experimental data shows that the pressure dynamics, which is experienced by the transducers, is in some cases quite different from the pressure dynamics in the pump chambers and produces pressure peaks which are not actually present in the original signal. The pressure transducers output was then also modelled in order to properly compare simulation results and experimental data.

This specification covers a zinc alloy in the form of die castings.

This specification covers a zinc alloy in the form of die castings.

This specification covers a zinc alloy in the form of die castings.

The ZA series of zinc alloys produce high strength die castings with the same cast-to size capability as the well proven SAE 903 alloy. The enhanced properties have been utilised in the two engine components described in this paper. ZA 27 has been used for the tooth belt drive camshaft pulley of a motorcycle engine and ZA8 has been used for the temperature resistant housing of a car ignition distributor.

SIMILAR SPECIFICATIONS—UNS Z33521, former SAE 903, ingot is similar to ASTM B 240-79, Alloy AG40A; and UNS Z33520, former SAE 903, die casting is similar to ASTM B 86-76, Alloy AG40A. UNS Z35530, former SAE 925, ingot is similar to ASTM B 240-79, Alloy AC41A; and UNS Z35531, former SAE 925, die casting is similar to ASTM B 86-82a, Alloy AC41A.

High damping capacity materials are useful in attenuating vibrations in mechanical structures such as functional automotive bracketry. The intrinsic damping properties of zinc alloys have only recently been systematically measured. Low and high frequency damping experiments have been conducted on die cast zinc alloys. and damping capacity has been measured as a function of temperature at high frequencies. The alloys show excellent damping properties over the range from 5 Hertz to a few hundred Hertz. for service applications from 40-80°C (104-176°F).

Traditional and new zinc-based casting alloys for functional and decorative applications are reviewed. Their compositions and standard alloy specifications are described, and recommendations for casting process selection and prototyping of applications are offered. The information presented shows the versatility achievable with zinc alloys. It is aimed at helping part designers make the most effective use of zinc for their component requirements.

Provision of a layer of zinc on aluminium to provide the fillets for soldering is well established but this usually necessitates a thick layer of zinc (>30μm) and soldering at temperatures below 450°C. New technology has been developed to enable sound joints to be made on aluminium heat exchangers using a much thinner layer of zinc (4 to 8 μm typically) on the aluminium component to provide the joint. By the correct combination of flux and zinc coating thickness, joints have been obtained over a wide range of heating conditions. Preferred temperature cycles are similar to those used by the industry today for brazing of Aluminium:Silicon braze-clad aluminium components which should facilitate tranfer by industry to the new technology.

The preceeding presentation explained the compositions of the zinc alloys. Now we can examine the properties that these combinations give rise to. In doing so, we must first understand the importance of each property to the design of any component. One must consider each of the properties individually so as to gain an understanding of cumulative effects and the relative importance of each property to the final application. The most effective way to attack the problem is to analyze the part's requirements with respect to applied stresses, environmental and operating conditions and economic constraints. While there are many mathematical models available to enable numerical analysis of property evaluations, they all rely on the same basic principle: The Total Systems Approach. That is, the consideration of all aspects of design. Properties evaluation is a critical step in this process.

Press-hardening steels get more and more popular for body in white applications as an approach to meet the demands of passenger safety and CO2 reduction. Unlike the larger part of the structure that is typically zinc coated, the majority of the PHS parts is either uncoated or aluminum silicon coated. This paper shall give an overview of press-hardening steels with zinc coatings with detailed results for corrosion resistance, weldability and mechanical properties for strength levels of 490 to 1800 MPa. Furthermore as for zinc coated material maintaining a robust press-hardening process is of even higher importance than for uncoated or AlSi coated material. A range of different processes including indirect and direct process are shown in detail. Especially the topic of micro-cracks, mechanisms and avoidance of micro-cracks in the direct process will be discussed. Results from industrial and semi industrial production are shown.

HOT-DIP galvanized steel sheets have been increasingly used in the automotive industry. However, two major problems occur during spot-welding because of the presence of zinc: 1/ Welding parameters differ from those used for bare sheets 2/ Electrodes life span often decreases. Two products have been thoroughly tested: 1/ Usinor MONOGAL® sheet 2/ Two-sides hot-dip galvanized sheet with various zinc-coating thicknesses. Welding parameters have been optimized by the determination of weldability lobes. Both products present a wide range of intensities, provided that weld current and electrode force are increased. The effect of an enventual variation of zinc-coating thickness is negligible. Electrodes life satisfies the FORD 2000 spot welds acceptance test. At last, temperature measurements inside the electrodes have shown the interest in increasing the electrodes tip diameter.

Interactions between a Zinc dialkyldithiophosphate (ZDP) and three different commercially available succinimide dispersants were observed through changes in solutions behavior, as determined by viscometry and Fourier Transform Infrared spectroscopy (FTIR), and four-ball tests. The viscometric response observed for two component blends of ZDP and succinimide dispersant in white oil changed as a function of the molar Zn to N ratio, indicative of specific interactions. The break in the viscometric response curve occurred at Zn:N=0.13 for all three succinimide dispersants. FTIR spectra of the same ZDP-dispersant blends were examined and similar Zn:N dependencies were observed. Four-ball tests measuring wear scar diameter, seizure load and weld load showed a dependence on the Zn to N ratio similar to that observed by viscometry. At very low Zn to N ratios wear and seizure load were decreased, while at higher ratios the seizure and weld loads were increased over that for ZDP alone.

Because of the drastic chilling involved in die casting and the fact that the solid solubilities of both aluminum and copper in zinc change with temperature, these alloys are subject to some aging changes, one of which is a dimensional change. Both of the alloys undergo a slight shrinkage after casting, which at room temperature is about two-thirds complete in five weeks. It is possible to accelerate this shrinkage by a stabilizing anneal, after which no further changes occur. The recommended stabilizing anneal is 3 to 6 h at 100 °C (212 °F), or 5 to 10 h at 85 °C (185 °F), or 10 to 20 h at 70 °C (158 °F). The time in each case is measured from the time at which the castings reach the annealing temperature. The parts may be air cooled after annealing. Such a treatment will cause a shrinkage (0.0004 in per in) of about two-thirds of the total, and the remaining shrinkage will occur at room temperature during the subsequent few weeks.

Zinc die casting products and metal casting processes continue to evolve for the benefit of end users. Through cooperative global research programs continuous improvements are still being made to the broad range of excellent mechanical properties, easy castability and the wide choice of finishes available for zinc die castings. Recent advances will be highlighted with case histories specific to automotive applications.

The role of zinc die castings in the materials marketplace has changed significantly in the last generation. In response to a shift in the available market, the industry has made major advances intended to improve competitiveness in both traditional and non-traditional areas. Better efficiency and performance have been achieved by the application of new methods and technologies. The ZA alloys, introduced to die casting during the last decade, have markedly expanded the capabilities of both zinc and the die casting process. This paper presents a review of several zinc die castings used in automatic applications.

Many papers have been written for SAE on electrochemical metallizing, a modern term for “selective” or “brush” plating. These papers have dealt primarily with the aerospace industry, including the use of non-embrittling cadmium LHE® coatings for corrosion protection on aircraft. Shadowed by 30 years of successes in the aerospace industry, electrochemical metallizing corrosion protection in the automotive industry is often overlooked. Specifically, the use of selectively applied zinc coatings for corrosion protection on wheel hubs during manufacture has proven integral at several European automotive manufacturers. In the past, environmental conditions have corroded both the hubs and wheels of automobiles. Quite often the corrosion is in the microscopic gap between the hub and the wheel, which over time causes the wheel to seize and prevents removal. This has been frustrating to both stranded motorists and shop mechanics.