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The level of boost pressure has a significant effect on optimizing the steady-state and transient performance of turbocharged diesel engines. However the problem of matching the wide speed range diesel engine and the high pressure turbocharging system has to be resolved. The regulated two-stage (RTS) system is an effective method to improve the fuel economy, transient response and smoke emissions. Compared with the difficult matching problem of the RTS system, the problem of boost pressure control is more complex due to the frequently changing operating conditions. To overcome the limitations of an open-loop control strategy, a closed-loop boost pressure control strategy was studied numerically using a mean value model of a diesel engine with RTS system. The system identification was conducted for the transient response from the turbine bypass opening command to the boost pressure.

Draw beads are commonly used in stamping operations to control sheet metal flow. The amount of sheet metal flow, or called draw-in amount, is an important index that controls the formability and quality of sheet metal parts. Numerical simulation of sheet metal forming processes is widely adopted. The draw-in map obtained through simulation serves as a guideline for successful die tryout and robust stamping. This study addresses some issues of using draw bead in simulations such as the calculation of draw bead holding and pulling forces, the thinning effect of real draw bead on draw-in amount, the adjustment of math based draw-in amount, the feasibility of using draw bead geometry in simulation, and the effect of draw bead location and configuration on sidewall curl.