New developments of advanced high-strength steels for automotive applications

Automotive industry asks for higher resistant steels to lighten parts and improve crash resistance. Keeping a good ductility while increasing tensile strength requires the development of new grades in which hardening mechanisms counteract the drop in elongation when enhancing mechanical resistance. This is mainly achieved with multiphase steels and completing dislocation hardening by twinning and martensite transformation during straining. This has led to high-strength steel families, some of them being already used in body in white (Dual Phase (DP) and TRIP steels). Others, still in development, will soon emerge on the market (Quenched and Partitioned (Q&P), medium-Mn steels or TWIP).     

高超音速飞行器及其关键技术简论

简要评述了高超音速飞行器及其关键技术, 包括: 高超音速飞行的定义、高超音速流动的特征、高超飞行覆盖范围、高超飞行器蒙皮温度、以及高超飞行设计特点; 高超飞行器的背景;高超飞行器研制的发展简史, 及经验与思考; 吸气式高超飞行器典型设计过程、发展战略、技术规划、和关键技术领域.      

Infrared seed inspection system (IRSIS) on painted car shells

This paper describes a newly-developed automated thermal system for detection of seeds on newly painted car shells. The system’s novel approach is to use thermal emission; previously applied techniques relied on light reflection strategies. The system is described beginning with analytical modeling of the underlying detection theory to verification on a pilot run in an automotive production line. Parker’s flash procedure, using a thermal detector, was performed to extract the thermal properties of inspected panels. New computer logic developed in-house for processing the acquired thermograms is also presented.     

Expert systems based on LCTV AND/OR logic

A problem in expert systems is typically represented by an AND/OR graph. A set of spatial light modulators which can perform AND and OR logic operations can directly be applied to form an optical inference engine. The threshold-dependence logic operations of relatively low contrast and small dynamic range liquid crystal television are explained. The parallel inference architecture operated by liquid crystal televisions is presented.     

Engine Modelling for Control Applications: A Critical Survey

In earlier work published by the author and co-authors, a dynamic enginemodel called a Mean Value Engine Model (MVEM) was developed. This model isphysically based and is intended mainly for control applications. In itsnewer form, it is easy to fit to many different engines and requires littleengine data for this purpose. It is especially well suited to embedded modelapplications in engine controllers, such as nonlinear observer basedair/fuel ratio and advanced idle speed control. After a brief review of thismodel, it will be compared with other similar models which can be found inthe literature. The attempt will be made to point out the differencesbetween the new modified MVEM and those developed elsewhere. In particular,the questions of fitting simplicity and general applicability are to betreated.     

Coupled radiation and turbulent multiphase flow in an aluminised solid propellant rocket engine

We present in this paper numerical simulations of coupled radiative transfer and turbulent flows at high temperature and pressure, typical of multiphase flows encountered in aluminised solid propellant rocket engines. The radiating medium is constituted of gases and of liquid or solid particles of oxidised aluminum. The turbulent flow of the gaseous phase is treated by using a four equation, low Reynolds number, boundary-layer-type turbulence model. The distributions of concentrations, temperatures, and temperature fluctuation variances of particles are calculated from a Lagrangian approach and a turbulence dispersion model. Thermal and mechanical non-equilibrium between the gas and different classes of particles is allowed. A locally one dimensional, iteratively based, radiative transfer solver is developed to compute wall fluxes and radiative source terms. It is shown that the thermal boundary layer attenuates significantly the radiative fluxes coming from the outer regions. Particle radiation is found to be much more important than gas radiation. Turbulent dispersion of particles in the boundary layer induces a decrease of particle concentration in the region of maximum turbulent kinetic energy, and then, decreases the attenuation effect of wall fluxes due to the boundary layer. The effects of turbulent temperature fluctuations are found to be small in the problem under consideration.     

我国汽车排气催化净化器的应用现状及发展趋势

本文评述了目前国内推广应用的各种汽车排气催化净化器的应用情况及其与发达国家的差距，并对国内汽车排气催化净化器的发展趋势及应用前景进行了描述。     

通用小型汽油机催化器应用研究

简要介绍了中国通用小型汽油机行业的现状及美国EPA对于通用小型汽油机的排放要求,并结合国内通用小型汽油机的排放统计现状,指出了催化器在通用小型汽油机行业应用的技术可能性,并针对通用小型汽油机的排放特点,指出了催化器应用于通用小型汽油机需注意的问题.     

The effect of basecoat pigmentation on mechanical properties of an automotive basecoat/clearcoat system during weathering

The aim of this study is to elucidate the effect of basecoat pigmentation on mechanical aspects of an automotive basecoat/clearcoat (BC/CC) system during artificial weathering exposures. A silver basecoat as the most reflective and a black basecoat as the most absorptive basecoat were selected. These two extreme behaviored basecoats were chosen with hopes that other basecoats would behave somewhere between the silver and the black extremes. The structural and mechanical properties of the coatings were investigated after various weathering exposure times (0, 150, 300, 450, 600 h). Dynamic mechanical thermal analysis (DMTA) was carried out to study variations in structure and basic characteristics of the system such as cross-linking density and T_g during weathering. In order to investigate variations in mechanical properties of the system, nano indentation, nano scratch, and tensile tests were also utilized.It was found that although both silver and black systems experienced post-curing reactions (dominant at earlier stages of weathering) and degradation reactions (dominant at later stages of weathering), but basecoat pigmentation affected the post-curing and degradation reaction rates of the BC/CC system, leading to variations in mechanical properties. It was concluded that post-curing occurred to a greater extent in the black pigmented system whilst in the silver pigmented system weathering degradation was much more sever.     

An analytical model for reverse automotive production planning and pricing

Automotive shredders need a reverse production planning strategy that includes determining at what price to purchase vehicle hulks from different sources. In this paper, we formulate the automotive reverse production planning and pricing problem in a nonlinear programming model, develop an approximate supply function for hulks when adjacent shredders price independently, and compare two hulk pricing strategies in three trends for ferrous metal and hulk prices: constant, increasing and decreasing. The case study results indicate that adjusting purchase price based on hulk composition in coordination with planning for purchasing, storing and processing can increase net revenue by 7–15%.