In MADI, investigations are carried out in the field of diesel engine working process perfection for complying with prospective ecological standards such as Euro-6 and Tier-4. The article describes the results of the first stage of experimental research of the influence of injection pressure up to 3000 bar on working processes of diesel engine and its fuel system. Justification of the design of a Common Rail injector for fuel injection under 3000 bar pressure is presented. The influence of raising injection pressure (up to 3000 bar) on the fuel spray propagation dynamics is demonstrated. The combined influence of injection pressure (up to 3000 bar) and air boost pressure on fuel spray propagation dynamics is shown, including on engine emission and noise.

Fuel injection causes considerable oscillations of fuel pressure at the injector inlet. One of the reasons is hydraulic impact when the needle valve closes. For multiple injections, the previous injections affect the following. As both the fuel pressure in rail pac and the injection rate grow, the oscillations increase. The pressure oscillation range at the common rail injector inlet at pac=1500 bar is up to 350 bar, and at the rail pressure pac=500 bar, the amplitude decreases to 80 bar. Physical properties of the fuel are also important. As the viscosity of the fuel increases, its hydraulic friction grows which results in a rapid damping of pressure oscillations. The data for an injector operating on sunflower oil is presented. As compared with diesel fuel, the oscillations range decreases from 400 to 250 bar at the same operating mode. The influence of the interval between the impulses of a double injection on the injection rate of the second fuel portion was investigated. Superposition of two waves during multiple injections may result in amplification and damping of the oscillations. Simulation was performed to estimate the influence of fuel type and time interval Δτ between control impulses of a double injection on the injection quantity of the second portion at pressures of 2000-3000 bar. When the rail pressure pac grows, the oscillations and their impact on the injection process increase. For diesel fuel at pressure of pac=2000 bar, the variation in injection rates of the second portion is 2.36-4.62 mg, and at pac=3000 bar – 1.58-6.63 mg.

Further tightening of environmental rules and standards regulating the content of toxic substances in diesel exhaust gases, accompanied by an increase in the requirements for their fuel efficiency, creates prerequisites for the creation of Russian common rail fuel systems (CR). The performance of this task is possible with the use of new engineering solutions in combination with computational and experimental research methods implemented on the basis of the integrated computational and experimental complex IKTS-MADI. The complex consists of computing and research components. The computing component of the IKTS-MADI allows calculating the working processes of the entire high-pressure line when the high-pressure fuel pump (HPFP), rail and electro-hydraulic common rail injectors (CRI) work together, taking into account the influence of wave phenomena on the distribution of injection parameters across diesel cylinders. Obtaining new data to expand the library of existing technical solutions and testing of fuel equipment samples designed using mathematical modeling are carried out on the research component of IKTS-MADI. The CR and its components are tested together with the control system (control unit, sensors and wiring harnesses). The injection characteristics required for calculating the diesel operating process are recorded.