A Low Pressure Pneumatic Direct Injection Two-Stroke Engine by Activated Radical Combustion Concept

1998 ◽  
Author(s):  
Yoichi Ishibashi ◽  
Masahiro Asai
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Stroke Engine

Study of a Small Two-Stroke Engine with Low-Pressure Air-Assisted Direct-Injection System

1991 ◽  
Author(s):  
Huei-Huay Huang ◽  
Yu-Yin Peng ◽  
Ming-Hong Jeng ◽  
James H. Wang
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Injection System ◽  
Stroke Engine

Application of Low Pressure Direct Injection and Semi-Direct Injection to a Small Capacity Two-Stroke Engine

2008 ◽  
Author(s):  
Franz Winkler ◽  
Roland Oswald ◽  
Oliver Schögl ◽  
Roland Kirchberger ◽  
Andreas Ebner
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Small Capacity ◽  
Stroke Engine

Comparison of Stratified and Homogeneous Combustion in a Direct-Injected Two-Stroke Engine for Snowmobile Applications

2008 ◽  
Author(s):  
Justin Johnson ◽  
Karen R. Den Braven
Keyword(s):  
Fuel Economy ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Homogeneous Combustion ◽  
Unburned Hydrocarbons ◽  
Stratified Combustion ◽  
Operation Results ◽  
Stroke Engine

Gasoline direct injection (GDI) two-stroke engine technology has been developed for use in snowmobile applications. Applying GDI to a two-stroke engine significantly reduces emissions of unburned hydrocarbons and improves fuel economy by reducing or eliminating the short circuiting of fuel that occurs in conventional carbureted two-stroke engines. The GDI design allows for two different modes of combustion, stratified and homogeneous. Stratified combustion is typically used during idle and light to moderate loads at low engine speeds while homogeneous combustion is used at moderate to high loads and medium to high engine speeds. This work presents the process and results of determining which mode of combustion provides better fuel economy during cruise point operation, and where the transition from stratified to homogeneous combustion should occur in snowmobile operation. Results show that homogeneous calibration is the superior mode of combustion for the cruise points of a snowmobile.

Paper 10: The Influence of Moisture on the Efficiency of a One-Third Scale Model Low Pressure Steam Turbine

1965 ◽  
Vol 180 (15) ◽  
pp. 39-49
Author(s):  
A. Smith
Keyword(s):  
Steam Turbine ◽  
Correction Factor ◽  
Rotational Speed ◽  
Direct Injection ◽  
Maximum Level ◽  
Low Pressure ◽  
Full Scale ◽  
Scale Model ◽  
Supersaturation Ratio ◽  
Multi Stage

The rapid increase in blade-tip diameters and peripheral speeds of low pressure turbines in large 3000 rev/min turbo-generators has presented the designer with many difficult mechanical and aerodynamic problems. To assist in the aerodynamic development of such blading, design studies on an experimental low pressure (l.p.) turbine were started early in 1959. Economic and technical considerations limited the choice to a one-third scale model steam turbine capable of running at three times the normal rotational speed to preserve full-scale working Mach numbers on the blading. Overall output and steam consumption were measured on a hydraulic dynamometer and by volumetric tanking respectively. The inlet steam temperature was controlled by a direct injection desuperheater so that the expansion could be kept dry for traversing or reduced to design inlet temperatures for normal wet running. Three multi-stage sets with last row blade diameters corresponding to 90-in, 120-in, and 136-in full-scale turbines have now been tested in the experimental turbine and the wet performance of the largest forms the subject of this paper. The overall wetness losses on the model 136-in diameter turbine have been assessed from a series of seven tests in which the inlet superheat and rotational speed were varied whilst maintaining fixed inlet and outlet pressure levels. To isolate the stage moisture correction factor (α), however, where a stage-by-stage approach was adopted, in which the dry stage efficiencies were initially established from interstage traverses under dry steam conditions. Two wet steam analyses were made, the first assuming equilibrium and the second supersaturated expansion, but the choice seemed immaterial since the moisture correction factor was almost the same for both. In the case of the supersaturated expansion calculation, it was necessary to establish the point of reversion from supersaturated to near equilibrium expansion (the Wilson point) and supplementary water extraction results were used to establish the maximum supersaturation ratio. These suggest that the maximum level is nearer to 3 in the model turbine than to the value of 4–6 quoted for convergent-divergent nozzles.

Investigations on Low Pressure Gasoline Direct Injection for a Standard GDI Combustion System

2010 ◽  
Author(s):  
Stephan Schmidt ◽  
Martin Joyce ◽  
Jonathan Wall ◽  
Alexander Trattner ◽  
Roland Kirchberger ◽  
...  
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Gasoline Direct Injection ◽  
Combustion System

Parametric study of combustion characteristics in a direct-injection diesel homogeneous charge compression ignition engine with a low-pressurefuel injector

2005 ◽  
Vol 6 (3) ◽  
pp. 215-230 ◽  
Author(s):  
Y Ra ◽  
E J Hruby ◽  
R D Reitz
Keyword(s):  
Numerical Simulations ◽  
Diesel Fuel ◽  
Homogeneous Charge Compression Ignition ◽  
Direct Injection ◽  
Low Pressure ◽  
Combustion Characteristics ◽  
Compression Ignition ◽  
Fuel Injector ◽  
Compression Ignition Engine ◽  
Homogeneous Charge

Homogeneous charge compression ignition (HCCI) combustion is an alternative to current engine combustion systems and is used as a method to reduce emissions. It has the potential nearly to eliminate engine-out NOx emissions while producing diesel-like engine efficiencies, when a premixture of gas-phase fuel and air is burned spontaneously and entirely by an autoignition process. However, when direct injection is used for diesel fuel mixture preparation in engines, the complex in-cylinder flow field and limited mixing times may result in inhomogeneity of the charge. Thus, in order to minimize non-uniformity of the charge, early injection of the fuel is desirable. However, when fuel is injected during the intake or early compression stroke, the use of high-pressure injection is limited by the relatively low in-cylinder gas pressure because of spray impingement on the cylinder walls. Thus, it is also of interest to consider low-pressure injectors as an alternative. In the present paper, the parametric behaviour of the combustion characteristics in an HCCI engine operated with a low-pressure fuel injector were investigated through numerical simulations and engine experiments. Parameters including the start-of-injection (SOI) timing and exhaust gas recirculation were considered, and diesel and n-heptane fuels were used. The results show good agreement of behaviour trends between the experiments and the numerical simulations. With its lower vaporization rates, significant effects of the SOI timing and intake gas temperature were seen for diesel fuel due to the formation of wall films. The modelling results also explained the origin of high-temperature NO x-producing regions due to the effect of the gas density on the spray.

Mixture preparation and combustion of CNG low-pressure compound direct injection spark-ignited engines

2011 ◽  
Vol 17 (6) ◽  
pp. 411-417 ◽  
Author(s):  
Chunming Hu ◽  
Shengzhi Hou ◽  
Zhangsong Zhan ◽  
Bin Liu ◽  
Na Liu ◽  
...  
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Mixture Preparation

Analysis of the Low Pressure Circuit of a Gasoline Direct Injection System

MTZ worldwide ◽  
2016 ◽  
Vol 77 (2) ◽  
pp. 56-61
Author(s):  
Michael Spitznagel ◽  
Uwe Iben ◽  
Ronny Leonhardt ◽  
Michael Bargende
Keyword(s):  
Direct Injection ◽  
Low Pressure ◽  
Gasoline Direct Injection ◽  
Injection System
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