Spray experiments of RP-3 jet fuel at non-evaporating and evaporating environments were studied on a constant volume spray chamber,and diffusive back-imaging technique was used to capture the transient spray developme...Spray experiments of RP-3 jet fuel at non-evaporating and evaporating environments were studied on a constant volume spray chamber,and diffusive back-imaging technique was used to capture the transient spray development processes.Spray tip penetration,projected spray area and cone angle of RP-3 jet fuel were derived from the spray development images,and compared to those of diesel fuel.It is observed that non-evaporating sprays of RP-3 jet fuel and diesel fuel do not exhibit significant differences,as their spray penetration distances,projected spray areas and spray cone angles are consistent at most test conditions.The evaporating sprays of RP-3 jet fuel produce shorter liquid-phase penetration distances and lower projected spray areas than those of diesel fuel,and these differences are particularly pronounced at low ambient temperatures.However,fuel effects on the evaporating spray cone angle are insignificant.Further,increased ambient density or ambient temperature shortens the liquid-phase spray penetration distance and reduces the liquid-phase spray area,and these effects are more pronounced for diesel fuel than RP-3 jet fuel.展开更多
Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic...Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic control unit, due to the system hydraulic lag or the possible communication malfunction. In this study,a simple estimate approach based on the injector inlet pressure is proposed to capture four critical characteristic instants at the start and end of injection. The critical characteristic moments estimated using this pressure-based approach are validated against those determined by the actual injection rate profiles, in the context of different single or split injection processes. The comparison revealed that the characteristic injection moments estimated by the injector inlet pressures and those determined by the actual injection rate profiles have a satisfactory agreement, certifying the broad applicability and reliability of this pressure-based approach in the detection of the real fuel injection start and end time.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.52022058 and 51776124)by Ministry of Education of China(Grant No.6141A020335)。
文摘Spray experiments of RP-3 jet fuel at non-evaporating and evaporating environments were studied on a constant volume spray chamber,and diffusive back-imaging technique was used to capture the transient spray development processes.Spray tip penetration,projected spray area and cone angle of RP-3 jet fuel were derived from the spray development images,and compared to those of diesel fuel.It is observed that non-evaporating sprays of RP-3 jet fuel and diesel fuel do not exhibit significant differences,as their spray penetration distances,projected spray areas and spray cone angles are consistent at most test conditions.The evaporating sprays of RP-3 jet fuel produce shorter liquid-phase penetration distances and lower projected spray areas than those of diesel fuel,and these differences are particularly pronounced at low ambient temperatures.However,fuel effects on the evaporating spray cone angle are insignificant.Further,increased ambient density or ambient temperature shortens the liquid-phase spray penetration distance and reduces the liquid-phase spray area,and these effects are more pronounced for diesel fuel than RP-3 jet fuel.
基金the National Natural Science Foundation of China(No.51306114)
文摘Fuel injection timing is an important control parameter for engine combustion optimization and emissions control. However, the actual fuel injection timing is different from the nominal one commanded by the electronic control unit, due to the system hydraulic lag or the possible communication malfunction. In this study,a simple estimate approach based on the injector inlet pressure is proposed to capture four critical characteristic instants at the start and end of injection. The critical characteristic moments estimated using this pressure-based approach are validated against those determined by the actual injection rate profiles, in the context of different single or split injection processes. The comparison revealed that the characteristic injection moments estimated by the injector inlet pressures and those determined by the actual injection rate profiles have a satisfactory agreement, certifying the broad applicability and reliability of this pressure-based approach in the detection of the real fuel injection start and end time.