Application of Air Assisted Direct Fuel Injection to Pressure Charged Gasoline Engines

Cathcart, Geoffrey; Tubb, John

doi:10.4271/2002-01-0705

Cited by 26 publications

(8 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Air assisted fuel injectors have been mooted in the past [27][28][29][30][31][32][33][34]. In these studies, air assisted atomisation displayed promise for enhancing fuel atomisation, but adoption of air assisted atomisation in a conventional ICE architecture has so far been deemed prohibitive by manufacturers, possibly due to the potential gain versus the complexity and cost of adding and operating an auxiliary high pressure air system.…”

Section: Conceptual Air Transfer Processmentioning

confidence: 99%

Starting to Unpick the Unique Air–Fuel Mixing Dynamics in the Recuperated Split Cycle Engine

et al. 2021

View full text Add to dashboard Cite

In this work air fuel mixing and combustion dynamics in the recuperated split cycle engine (RSCE) are investigated through new theoretical analysis and complementary optical experiments of the flow field. First, a brief introduction to the basic working principles of the RSCE cycle will be presented, followed by recent test bed results relevant to pressure traces and soot emissions. These results prompted fundamental questioning of the air-fuel mixing and combustion dynamics taking place. Hypotheses of the mixing process are then presented, with differences to that of a conventional Diesel engine highlighted. Moreover, the links of the reduced emissions, air transfer processes and enhanced atomisation are explored. Initial experimental results and Schlieren images of the air flow through the poppet valves in a flow rig are reported. The Schlieren images display shockwave and Mach disk phenomena. Demonstrating supersonic air flow in the chamber is consistent with complementary CFD work. The results from the initial experiment alone are inconclusive to suggest which of the three suggested mixing mechanism hypotheses are dominating the air–fuel dynamics in the RSCE. However, one major conclusion of this work is the proof for the presence of shockwave phenomena which are atypical of conventional engines.

show abstract

Section: Conceptual Air Transfer Processmentioning

confidence: 99%

Starting to Unpick the Unique Air–Fuel Mixing Dynamics in the Recuperated Split Cycle Engine

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In order to overcome this problem and also to allow liquid and vapour phases to be displayed separately the laser induced Exciplex fluorescence (LIEF) method was developed [4][5][6][7][8][9][10]. With this technique two dopants with very similar emission wavelengths are added to the fuel.…”

Section: The Traditional Laser Induced Fluorescence (Lif)mentioning

confidence: 99%

“…The main injector then injects not only the fuel metered by the PFI injector but also a quantity of compressed air into the cylinder. This has the effect of dramatically improving the atomisation of the fuel, allowing the use of a very low injection pressure which in turn reduces the velocity and hence the penetration of the spray into the cylinder [10]. A typical injection sequence is shown in Figure 4.…”

Section: Fuel Systemmentioning

confidence: 99%

Two-phase Fuel Distribution in an Air Assisted DI Gasoline Engine(S.I. Engines, Combustion Diagnostics)

Leach¹,

Zhao²,

Li³

et al. 2004

COMODIA

View full text Add to dashboard Cite

During the injection and mixture formation processes of a DI gasoline engine fuel may exist in either the liquid or vapour phase and it is therefore advantageous to be able to observe both phases simultaneously. However, traditional LIF techniques are not suitable for this purpose since the large differences in fluorescence intensity from the two phases make the selection of a suitable light collection level virtually impossible. In an attempt to overcome this problem the Laser Induced Exiplex Fluorescence (LIEF) technique was applied to a single cylinder DI gasoline engine. The engine was equipped with an air assisted fuel injection system and it had full optical access through a quatz liner and transparent piston crown. Isooctane was used as the test fuel with dopants Naphthalene (7%) and N,N-dimethlylaniline (DMA) (7%). The expanded laser beam from a XeCl Excimer laser was used to illuminate the whole combustion chamber and act as the excitation source for the LIEF system. In order to collect simultaneously fluorescence signals from both liquid and vapour phases emissions an image doubling and filtering system was designed and constructed. The fluorescence images were recorded from the front of the cylinder, perpendicular to the axis of the crankshaft. In order to investigate the effect of absorption on the fluorescence signal the beam was introduced to the cylinder from 3 directions. Initially the beam entered from the left of the image. The experiment was then repeated with the beam entering from the right and finally entering from below through the transparent piston crown. The crank angle resolved results, from the start of injection to the end of the compression stroke are presented with an image for each illumination direction.

show abstract

“…Air-assist atomization was used by Rudolf Diesel in the first compression-ignition engines [8], and remained in use on larger engines into the 1940s [9]. The Orbital injector system uses a type of airassist atomization for spark-ignited direct-injection gasoline-fuelled engines [10]. In these systems, gas is used only to help disperse the liquid, not as the primary fuel.…”

Section: Introductionmentioning

confidence: 99%

Compression ignition of directly injected natural gas with entrained diesel

Laforet

Brown

Rogak

et al. 2010

International Journal of Engine Research

View full text Add to dashboard Cite

A new fuel injector prototype for heavy-duty engines has been developed to use direct-injection natural gas with small amounts of entrained diesel as an ignition promoter. This 'co-injection' is quite different from other dual-fuel engine systems where diesel and gas are introduced separately. In an engine with co-injection, diesel and gas are injected simultaneously through one set of nozzle holes as the piston approaches top dead centre. Most of the combustion is non-premixed, as in a conventional diesel engine, but the natural gas supplies over 90 per cent of the energy for typical operating conditions. Reliable compressionignition can be attained, but two injections per engine cycle are often needed to minimize engine knock. The present paper focuses on 800 r/min light-load operation (equivalence ratio between 0.05 and 0.22) with a single injection per cycle, in order to better understand how the ignition process is affected by in-cylinder conditions and the gas/diesel ratio. Two techniques were used to explore the data: response surface methodology and power-law fits. These methods both showed above a certain diesel/gas ratio that ignition delay approached that of pure diesel injections, but significant knock would occur if the total fuel energy of the injection was high. With high injection pressure and low cylinder pressure, the region of allowable diesel flow (i.e. the region with low knock intensity and high combustion efficiency) was increased for cases with low to moderate gas flow compared with low injection pressure. Injection pressure had little effect at high cylinder pressure, and had no significant effect on ignition delay.

show abstract

Application of Air Assisted Direct Fuel Injection to Pressure Charged Gasoline Engines

Cited by 26 publications

References 5 publications

Starting to Unpick the Unique Air–Fuel Mixing Dynamics in the Recuperated Split Cycle Engine

Starting to Unpick the Unique Air–Fuel Mixing Dynamics in the Recuperated Split Cycle Engine

Two-phase Fuel Distribution in an Air Assisted DI Gasoline Engine(S.I. Engines, Combustion Diagnostics)

Compression ignition of directly injected natural gas with entrained diesel

Contact Info

Product

Resources

About