Liquid fuel distribution in the combustion chamber by jet impingement on small cylindrical obstacles

Fuel ◽  
2021 ◽  
Vol 304 ◽  
pp. 121387
Author(s):  
Saeed Kazemi Seresht ◽  
Arash Mohammadi
Keyword(s):  
Combustion Chamber ◽  
Liquid Fuel ◽  
Jet Impingement ◽  
Fuel Distribution

Flow Dynamics of Charge Stratification in Small GDI Two-Stroke Engines

2002 ◽  
Author(s):  
Stefania Zanforlin ◽  
Roberto Gentili ◽  
Pierluigi Dell’Orto
Keyword(s):  
High Pressure ◽  
Combustion Chamber ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Flow Dynamics ◽  
Mixing Process ◽  
Stratified Charge ◽  
Fuel Distribution ◽  
Multidimensional Modelling ◽  
Partial Loads

Direct high-pressure liquid fuel injection is able to control the mixing process inside the cylinder for getting either stratified charge at partial loads or quasi-homogeneous conditions, as it is required at full load. This paper shows the development of this solution for small two-stoke engines, using multidimensional modelling. The aim is investigating how the design of scavenging ducts and combustion chamber influences charge stratification behaviour, taking into account fuel distribution and stratification stability varying engine load and speed.

Comparisons of Diesel Spray Liquid Penetration and Vapor Fuel Distributions With In-Cylinder Optical Measurements

1999 ◽  
Vol 122 (4) ◽  
pp. 588-595 ◽  
Author(s):  
Laura M. Ricart ◽  
Rolf D. Reltz ◽  
John E. Dec
Keyword(s):  
Liquid Fuel ◽  
Laser Diagnostics ◽  
Operating Conditions ◽  
Optical Measurements ◽  
Fuel Distribution ◽  
Wide Range ◽  
Model Predictions ◽  
Soot Distribution ◽  
Breakup Model ◽  
Vapor Distribution

The performance of two spray models for predicting liquid and vapor fuel distribution, combustion and emissions is investigated. The model predictions are compared with extensive data from in-cylinder laser diagnostics carried out in an optically accessible heavy-duty, D. I. diesel engine over a wide range of operating conditions. Top-dead-center temperature and density were varied between 800 K and 1100 K and 11.1 and 33.2 kg/m3, respectively. Two spray breakup mechanisms were considered: due to Kelvin-Helmholtz (KH) instabilities and to Rayleigh-Taylor (RT) instabilities. Comparisons of a wide range of parameters, which include in-cylinder pressure, apparent heat release rate, liquid fuel penetration, vapor distribution and soot distribution, have shown that a combination of the KH and the RT mechanisms gives realistic predictions. In particular, the limited liquid fuel penetration observed experimentally was captured by including these two competing mechanisms in the spray model. Furthermore, the penetration of the vapor fuel ahead of the liquid spray was also captured. A region of high soot concentration at the spray tip was observed experimentally and also predicted by the KH-RT spray breakup model. [S0742-4795(00)01504-0]

Post-Combustion In-Cylinder Vaporization During Cranking and Startup in a Port-Fuel–Injected Spark Ignition Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 397-402 ◽  
Author(s):  
Jim S. Cowart
Keyword(s):  
Combustion Chamber ◽  
Liquid Fuel ◽  
Combustion Process ◽  
Spark Ignition ◽  
Liquid Films ◽  
Spark Ignition Engine ◽  
Fuel Vapor ◽  
Intake Port ◽  
Warm Up ◽  
Flame Ionization

During port-fuel–injected (PFI) spark-ignition (SI) engine startup and warm-up fuel accounting continues to be a challenge. Excess fuel must be injected for a near stoichiometric combustion charge. The “extra” fuel that does not contribute to the combustion process may stay in the intake port or as liquid films on the combustion chamber walls. Some of this combustion chamber wall liquid fuel is transported to the engine’s oil sump and some of this liquid fuel escapes combustion and evolves during the expansion and exhaust strokes. Experiments were performed to investigate and quantify this emerging in-cylinder fuel vapor post-combustion cycle by cycle during engine startup. It is believed that this fuel vapor is evaporating from cylinder surfaces and emerging from cylinder crevices. A fast in-cylinder diagnostic, the fast flame ionization detector, was used to measure this behavior. Substantial post-combustion fuel vapor was measured during engine startup. The amount of post-combustion fuel vapor that develops relative to the in-cylinder precombustion fuel charge is on the order of one for cold starting (0 °C) and decreases to ∼13 for hot starting engine cycles. Fuel accounting suggests that the intake port puddle forms quickly, over the first few engine cranking cycles. Analysis suggests that sufficient charge temperature and crevice oxygen exists to at least partially oxidize the majority of this post-combustion fuel vapor such that engine out hydrocarbons are not excessive.

Semiempirical Analysis of Liquid Fuel Distribution Downstream of a Plain Orifice Injector Under Cross-Stream Air Flow

1982 ◽  
Vol 104 (4) ◽  
pp. 788-795 ◽  
Author(s):  
Ming-hua Cao ◽  
Hong-kun Jiang ◽  
Ju-shan Chin
Keyword(s):  
Ambient Temperature ◽  
Test Data ◽  
High Velocity ◽  
Liquid Fuel ◽  
Air Flow ◽  
Liquid Sheet ◽  
Flow Path ◽  
Preliminary Design ◽  
Fuel Injector ◽  
Fuel Distribution

An improved semiempirical analysis is presented for the liquid fuel distribution downstream of a plain orifice fuel injector under a cross-stream air flow of uniform high velocity and constant ambient temperature. The analysis is based on a simplified “flat-fan spray” model (ε–ψ model). A ε–ψ model is proposed which assumes that the fuel injected through the orifice forms a flat-fan liquid sheet with an average fan angle 2ψ0. Once the droplets have been formed, the trajectory of individual droplets determines the fuel distribution downstream. The validity of the analysis is confirmed by comparison of calculations based on the ε–ψ model and test data obtained from fuel distribution experiments under cross-stream air flow of ambient temperature. The agreement is shown to be very good. The semiempirical analysis presented offers a very useful approach in the preliminary design of the fan air flow path portion of turbofan afterburners.

scholarly journals Investigations of the Working Process in a Dual-Fuel Low-Emission Combustion Chamber for an FPSO Gas Turbine Engine

2020 ◽  
Vol 27 (3) ◽  
pp. 89-99
Author(s):  
Serhiy Serbin ◽  
Badri Diasamidze ◽  
Marek Dzida
Keyword(s):  
Nitrogen Oxides ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Turbulent Flame ◽  
Dual Fuel ◽  
Working Process ◽  
Fuel Supply ◽  
Low Emission ◽  
Gas Turbine Combustion

AbstractThis investigation is devoted to an analysis of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. The low-emission gas turbine combustion chamber with partial pre-mixing of fuel and air inside the outer and inner radial-axial swirlers was chosen as the object of research. When modelling processes in a dual-flow low-emission gas turbine combustion chamber, a generalized method is used, based on the numerical solution of the system of conservation and transport equations for a multi-component chemically reactive turbulent system, taking into consideration nitrogen oxides formation. The Eddy-Dissipation-Concept model, which incorporates Arrhenius chemical kinetics in a turbulent flame, and the Discrete Phase Model describing the interfacial interaction are used in the investigation. The obtained results confirmed the possibility of organizing efficient combustion of distillate liquid fuel in a low-emission gas turbine combustion chamber operating on the principle of partial preliminary formation of a fuel-air mixture. Comparison of four methods of liquid fuel supply to the channels of radial-axial swirlers (centrifugal, axial, combined, and radial) revealed the advantages of the radial supply method, which are manifested in a decrease in the overall temperature field non-uniformity at the outlet and a decrease in nitrogen oxides emissions. The calculated concentrations of nitrogen oxides and carbon monoxide at the flame tube outlet for the radial method of fuel supply are 32 and 9.1 ppm, respectively. The results can be useful for further modification and improvement of the characteristics of dual-fuel gas turbine combustion chambers operating with both gaseous and liquid fuels.

The Development Problems of Two-Fuel Burner for the Gas Turbine Combustion Chamber

2021 ◽  
Author(s):  
A. Yu Vasilyev ◽  
O. G. Chelebyan ◽  
A. I. Maiorova ◽  
A. N. Tarasenko ◽  
D. S. Tarasov ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Reverse Flow ◽  
Experimental Studies ◽  
Injection Pressure ◽  
Spray Angle ◽  
Preliminary Experimental Data ◽  
Fuel Injection Pressure ◽  
Air Channels

Abstract The work is devoted to the design of a spraying device for the combustion chamber GTE-65.1 on liquid fuel. The paper presents the following results: 1) The 3D calculations of the air channels characteristics for two burners types — pilot and main — were carried out. Data were obtained on the flow and pressure fields inside and at the burners outlet, and also the volumes of the reverse flow zones. 2) The main and pilot nozzles have been designed for the two spraying devices types. The values of droplet dispersity and spray angle were obtained, depending on the fuel injection pressure. 3) Based on the calculations carried out, the models of two spraying liquid fuel devices were designed and manufactured, the design of which is based on the design of the single-fuel combustion chamber (CC) on natural gas burners for GTE-65.1. At the next stage of the work, it is planned to carry out experimental studies of the two devices models aimed at obtaining an aerosol mixture with the desired properties to ensure uninterrupted operation of the GTE-65.1 on liquid fuel. Some preliminary experimental data are presented in this paper.

Monitoring of Gasoline Fuel Distribution in a Research Engine

1992 ◽  
Vol 206 (2) ◽  
pp. 107-115 ◽  
Author(s):  
E Winklhofer ◽  
G K Fraidl ◽  
A Plimon
Keyword(s):  
Combustion Chamber ◽  
Significant Influence ◽  
Engine Performance ◽  
Cylinder Liner ◽  
Operating Mode ◽  
Fuel Distribution ◽  
Gasoline Engines ◽  
Operating Modes ◽  
Ignition And Combustion ◽  
Absorption Measurements

Fuel distribution in gasoline engines has significant influence on the cyclic stability of charge ignition and combustion, and hence on engine performance parameters related to the variation of combustion and heat release. There are numerous ways to influence in-cylinder fuel distribution by means of mixture preparation systems, engine aspiration or by combustion chamber geometry itself. However, methods to observe in-cylinder fuel distribution are scarce, and very often charge distribution—homogeneous or highly stratified—is just heuristically assessed, based on engine performance data. Therefore, a method has been devised which allows observation of vaporized fuel in the cylinders of optically accessed engines. The method, based on the absorption of infra-red laser light radiation by hydrocarbon molecules, needs optical access to the combustion chamber to transmit a laser beam of appropriate wavelength and to monitor the attenuation caused by absorption and scattering. The paper describes the concept of the measurement technique and its application to an optically accessed single-cylinder research engine. The engine is equipped with a transparent cylinder liner to allow investigation of the entire cylinder volume. In order to evaluate the feasibility of the method, the response of the line-of-sight absorption measurements to various engine operating modes was investigated. A comparison with actual engine data showed that fuel distribution, as governed by the injector operating mode, can have significant influence on combustion and cycle-to-cycle stability.

Semiempirical Analysis of Fuel-Air Ratio Distribution Downstream of a Plain Orifice Injector Under Nonuniform Crossflow

1986 ◽  
Vol 108 (1) ◽  
pp. 204-208
Author(s):  
J. S. Chin ◽  
W. M. Li ◽  
M. H. Cao
Keyword(s):  
Experimental Data ◽  
Average Velocity ◽  
Liquid Fuel ◽  
Design Tool ◽  
Ratio Distribution ◽  
Fuel Distribution ◽  
Good Design ◽  
Average Flow ◽  
Maximum Value ◽  
Good Agreement

The present paper is a step further and a modification of the semiempirical analysis of liquid fuel distribution downstream of a plain orifice injector proposed previously [1]. It has been improved from the previous paper in two aspects: (i) the use of experimental data of plain orifice atomization under crossflow obtained by the present authors instead of using Ingebo’s correlation [2], and (ii) consideration taken of the effect of a nonuniform crossflow. The agreement between the calculated results and the experimental data on fuel-air ratio distribution is quite good. In particular the model is capable of predicting the maximum value of the fuel-air ratio distribution and its position. The model has been used for the calculation of fuel-air ratio distribution under nonuniform crossflow with different average flow velocities. Thus the authors are able to predict how the position of maximum fuel-air ratio changes with average velocity for the same profile. The results are in good agreement with the experimental data. From the results of present research the authors conclude that for fuel-air ratio prediction in afterburners or ramjets, it is necessary to consider the effects of nonuniform crossflow. The present semiempirical analysis provides a good design tool for combustor development.

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