An Optical Engine Used as a Physical Model for Studies of the Combustion Process Applying a Two-Color Pyrometry Technique

Abstract

This work describes an experimental installation for the investigation of the combustion and injection processes. This installation is based on a two-stroke direct injection diesel engine with a total displacement of 3 L and a cylinder head equipped with three quartz windows. The windows are optical accesses that allow studying the process of injection, the atomization and evaporation of the fuel jet in an inert atmosphere (nitrogen), and the combustion process in a reactive atmosphere (ambient air). Additionally, the application of a two-color pyrometry technique to measure soot formation in this facility is presented. A methodological study is carried out regarding the influence of the dynamic range of the detectors and the wavelengths used. Maps of KL2C, flame temperature, and error probability are presented. The use of cameras with high dynamic range provides better results since the system seems to be less sensitive to measurement noise, and fewer points are obtained with a non-physical solution. Moreover, an appropriate combination of interference filters can improve the reliability of the solution. The greater the difference between the wavelengths of both interference filters, the fewer points with a non-physical solution, which improves the reliability of results.

Macroscopic Parameters of Fuel Sprays Injected in an Optical Reciprocating Single-Cylinder Engine: An Approximation by Means of Visualization with Schlieren Technique

“…The tests were carried out in an optically accessible experimental facility, which is described in detail in [ 17 ]. It is based on a two-stroke single-cylinder diesel engine (Jenbach JW-50), with a displacement of 3 L and an effective compression ratio of around 9.5/1.…”

“…Experimental setups with optical accesses allow the application of optical techniques for this purpose. One of these techniques is the Schlieren one, that allows visualizing the fuel spray to determine its penetration, area and cone angle (macroscopic parameters) [ 16 , 17 , 18 ]. In addition, this technique also makes it possible to obtain the ignition delay of the fuel [ 19 ].…”

A CFD Modelling Approach of Fuel Spray under Initial Non-Reactive Conditions in an Optical Engine

“…Experimental tests were carried out on a single-cylinder two-stroke diesel engine (Jenbach JW-50), which is explained in detail in [30]. It has an effective compression ratio of 9.5 and a displacement of 3 L. The experimental facility is optically accessible as it has four accesses on each side of the cylinder head.…”

Spray Momentum Flux Novel Estimation Procedure through the Fuel Rate of Injection Using Hydrogenated Fuels with Single Hole Nozzle Diesel Injector

“…The MF consists of measuring the impact of the fuel on a piezoelectric sensor that is inside a chamber filled with an inert gas. , This parameter is very important for predicting the blend potential of injection processes to achieve an efficient combustion process with low pollutants formation. Important factors such as spray penetration and cone angle, and air entrainment largely depend on the spray impulse. − Knowing this parameter, information is obtained about the flow exit velocity and the mass flow rate, thus controlling the air–fuel mixing together with the ambient density. − …”

“…Important factors such as spray penetration and cone angle, and air entrainment largely depend on the spray impulse. 23 − 27 Knowing this parameter, information is obtained about the flow exit velocity and the mass flow rate, thus controlling the air–fuel mixing together with the ambient density. 28 − 30 …”