Effect of the In-Cylinder Back Pressure on the Injection Process and Fuel Flow Characteristics in a Common-Rail Diesel Injector Using GTL Fuel

Abstract

The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liquid fuel (GTL) on the injection process, fuel flow conditions, and cavitation formation in a modern common-rail injector. First, the influence on injection characteristics was studied experimentally using an injection system test bench, and numerically using the one-dimensional computational program. Afterward, the influence of fuel properties on internal fuel flow was studied numerically using a computational program. The flow inside the injector was considered as multiphase flow and was calculated through unsteady Computational Fluid Dynamics simulations using a Eulerian–Eulerian two-fluid approach. Finally, the influence of in-cylinder back pressure on the internal nozzle flow was studied at three distinctive back pressures. The obtained numerical results for injection characteristics show good agreement with the experimental ones. The results of 3D simulations indicate that differences in fuel properties influence internal fuel flow and cavitation inception. The location of cavitation formation is the same for both fuels. The cavitation formation is triggered regardless of fuel properties. The size of the cavitation area is influenced by fuel properties and also from in-cylinder back pressure. Higher values of back pressure induce smaller areas of cavitation and vice versa. Comparing the conditions at injection hole exit, diesel fuel proved slightly higher average mass flow rate and velocities, which can be attributed to differences in fluid densities and viscosities. Overall, the obtained results indicate that when considering the injection process and internal nozzle flow, GTL fuel can be used in common-rail injection systems with solenoid injectors.

Zero-Dimensional Modeling of the Rate of Injection with a Diesel Common Rail System Using Single-Hole Nozzles with Neat Low-Carbon Fuels

“…Regarding the fuels, in all cases, more diesel fuel is injected, followed by HVO, and finally, GtL fuel, although the difference between them is slight. This result may be because cavitation is higher with GtL [56] and HVO fuels [41]. In Supplementary Materials, Tables S2-S4, show the injection timing values concerning the injector energizing of the experimental tests with every nozzle.…”

Obtaining the Synthetic Fuels from Waste Plastic and Their Effect on Cavitation Formation in a Common-Rail Diesel Injector

“…For the chosen medium mesh, the time-step independence study was conducted similarly to the mesh independence study. Three time steps, separated by a factor of ten, as shown in Table 8, were selected based on our experience [16]. The total injected fuel mass per injection cycle was monitored to analyse the time-step independence.…”

“…From the above short review of pyrolytic oils, it can be seen that plastic waste presents a suitable raw material for synthetic fuel production and has considerable potential for its usage in internal combustion engines as a substitute or additive to conventional fossil fuels. However, small differences in PO properties, compared to conventional fuels, can have an influence on internal fuel flow in diesel injectors, which will further influence spray formation, fuel combustion, and the emission formation process in modern diesel engines, where injection pressures are very high and injection times very short [16,17]. There are many studies in which the influence of different fuel properties on fuel flow conditions in common-rail diesel injectors was studied experimentally and/or numerically.…”

Influence of Spray Nozzle Operating Parameters on the Fogging Process Implemented to Prevent the Spread of SARS-CoV-2 Virus

“…In this respect, there is a noticeable scarcity of knowledge that needs to be supplemented with publications that extend to areas beyond the fogging process. Such publications mostly concern processes of the same nature, e.g., fuel spraying [18][19][20][21][22], water spray processes as part of fire protection systems [23,24], as well as issues related to ventilation and air conditioning [25]. Such studies often are concerned with the questions related to the maldistribution of air, which forms an important indication of the directions of disinfectant spray distribution in the enclosed space where the fumigation process is carried out.…”