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This paper presents a computer model for simulating dynamic responses inside an injector of an automotive fuel rail system. The injector contains a filter at the top, a coil spring in the middle, and a needle and orifices at the bottom. The equations of motion for unsteady one-dimensional flow are derived for the fluid flowing through the injector. The needle motion is described by a second order ordinary differential equation. The forces exerted on the needle include the magnetic force that controls the opening and closing of the injector and the coil spring force. To account for the loss of kinetic energy, we define two loss factors Ka and Kb. The former describes the loss of kinetic energy as fluid enters the injector through the filter at the top, and the latter depicts that as fluid is ejected into a large chamber through the passage between the needle and the needle seat and across four orifices at the bottom of the injector.

A computer model is developed for predicting pressure fluctuations inside an automotive electronic fuel rail system, which consists of six injectors connected in series through pipelines and a pressure regulator. The pressure fluctuations are mainly caused by opening and closing of injectors fired in a particular order. The needles that control the opening and closing of the injectors are modeled by mass- spring-dashpot systems, whose equations of motion are governed by a second order ordinary differential equations. A similar second order ordinary differential equation is used to describe the motion of the membrane with nonlinear stiffness inside the pressure regulator. The responses of injectors and pressure regulator are coupled by unsteady one-dimensional flow through the pipelines. The pressure fluctuations are also required to satisfy a one-dimensional damped wave equation. To validate this computer model, pressure fluctuations inside injectors and pipelines are calculated.

The adoption of lithium-ion batteries in vehicle electrification is fast growing due to high power and energy demand on hybrid and electric vehicles. However, the battery overall performance changes with time through the vehicle life. This paper investigates the electric vehicle battery cell aging under different usages. Battery cell experimental data including open circuit voltage and internal resistance is utilized to build a typical electric vehicle model in the AVL-Cruise platform. Four driving cycles (WLTP, UDDS, HWFET, and US06) with different ambient temperatures are simulated to acquire the battery cell terminal currents. These battery cell terminal current data are inputs to the MATLAB/Simulink battery aging model. Simulation results show that battery degrades quickly in high ambient temperatures. After 15,000 hours usage in 50 degrees Celsius ambient temperature, the usable cell capacity is reduced up to 25%.