The Interaction of Air Motion, Fuel Spray, and Combustion in the Diesel Combustion Process

1972 ◽  
Vol 94 (1) ◽  
pp. 11-14
Author(s):  
R. B. Melton ◽  
A. R. Rogowski
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Central Area ◽  
Combustion Efficiency ◽  
Fuel Spray ◽  
Spray Penetration ◽  
Buoyancy Forces ◽  
Fluid Jets ◽  
Air Mixing

This paper is pertinent mainly to combustion in open-chamber diesel engines employing air swirl. It is shown how an increase in air swirl rate can cause a marked loss of combustion efficiency unless fuel spray penetration is increased. High swirl reduces radial fuel spray penetration with central injection and the resulting excess fuel in the central area may be trapped by buoyancy forces following ignition, becoming isolated for as much as a tenth of a second in a chamber of four in. diameter. A brief explanation of fuel injection in terms of the mechanics of fluid jets is given and circumstances described in which buoyancy forces assist fuel-air mixing following ignition.

Fuel Efficiency – Challenges and Innovations in Emulsified Fuel Technology

2015 ◽  
Author(s):  
Jerry Ng ◽  
Kaisa Honkanen
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Combustion Efficiency ◽  
Secondary Atomization ◽  
Emulsified Fuel ◽  
Main Challenge ◽  
Marine Diesel ◽  
Initial Fuel ◽  
Fuel Technology

Emulsified fuel technology has been developed since the early 1980’s to the improve combustion efficiency of marine diesel engines by creating a secondary atomization effect after the initial fuel injection. The main challenge is to measure the improved sfoc of ships accurately and reliably. This paper presents a proposed method to measure the sfoc accurately and reliably to the order of 1%. Electronic governor also poses new challenge to measuring the sfoc of ships burning emulsified fuel. Meanwhile, fuel types supplied to ship owners are of increased varying properties although still complying to ISO8217 standard. This paper describes the innovations in emulsified fuel technology that were developed to meet these challenges.

Diesel Engine Intake Condition Control-Oriented Models for Active Fuel Injection Profile Control

2011 ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
High Fidelity ◽  
Exhaust Gas ◽  
Engine Model ◽  
Profile Control ◽  
Gas Recirculation

Fueling control in Diesel engines is not only of significance to the combustion process in one particular cycle, but also influences the subsequent dynamics of air-path loop and combustion events, particularly when exhaust gas recirculation (EGR) is employed. To better reveal such inherently interactive relations, this paper presents a physics-based, control-oriented model describing the dynamics of the intake conditions with fuel injection profile being its input for Diesel engines equipped with EGR and turbocharging systems. The effectiveness of this model is validated by comparing the predictive results with those produced by a high-fidelity 1-D computational GT-Power engine model.

Scaling liquid penetration in evaporating sprays for different size diesel engines

2019 ◽  
Vol 21 (9) ◽  
pp. 1662-1677 ◽  
Author(s):  
Xinyi Zhou ◽  
Tie Li ◽  
Yijie Wei ◽  
Ning Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Speed ◽  
Scaling Laws ◽  
Fuel Injection ◽  
Pollutant Emissions ◽  
Liquid Penetration ◽  
Spray Characteristics ◽  
Penetration Length ◽  
Air Mixing

Scaled model experiments can greatly reduce the cost, time and energy consumption in diesel engine development, and the similarity of spray characteristics has a primary effect on the overall scaling results of engine performance and pollutant emissions. However, although so far the similarity of spray characteristics under the non-evaporating condition has been studied to some extent, researches on scaling the evaporating sprays are still absent. The maximum liquid penetration length has a close relationship with the spray evaporation processes and is a key parameter in the design of diesel engine spray combustion system. In this article, the similarity of maximum liquid penetration length is theoretically derived based on the hypotheses that the spray evaporation processes in modern high-pressure common rail diesel engines are fuel–air mixing controlled and local interphase transport controlled, respectively. After verifying that the fuel injection rates are perfectly scaled, the similarity of maximum liquid penetration length in evaporating sprays is studied for three scaling laws using two nozzles with hole diameter of 0.11 and 0.14 mm through the high-speed diffused back-illumination method. Under the test conditions of different fuel injection pressures, ambient temperatures and densities, the lift-off law and speed law lead to a slightly increased maximum liquid penetration length, while the pressure law can well scale the maximum liquid penetration length. The experimental results are consistent with the theoretical analyses based on the hypothesis that the spray evaporation processes are fuel–air mixing controlled, indicating that the local interphase transports of energy, momentum and mass on droplet surface are not rate-controlled steps with respect to spray evaporation processes.

Paper 2: Similarity Considerations in Assessing Diesel Engine Fuel Spray Requirements

1965 ◽  
Vol 180 (14) ◽  
pp. 10-29 ◽  
Author(s):  
B. E. Knight
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Spray ◽  
Theoretical Expression ◽  
Engine Fuel ◽  
Wide Range ◽  
Air Mixing ◽  
Dimensionless Variables ◽  
Mixing Problem

A simplified dimensional analysis has been made of the fuel-air mixing problem in diesel engines. The dimensionless variables describing the mixing pattern have been expressed in terms of the dimensionless variables describing the engine and fuel injection conditions by means of explicit equations with numerical values for the constants. A wide range of such equations has been derived and tables of numerical values are given as examples, together with examples of engine air motion calculations for comparison. A theoretical expression for fuel-spray penetration into a cross-wind has been compared with a few experimental results. Engine smoke and specific consumption measurements have been plotted against the appropriate dimensionless variables in two instances. In both instances the response of the engine to the variables is quite different. It is believed that the wide range of methods of engine performance data analysis outlined in this paper will make a significant contribution to progress in understanding diesel engine combustion.

Investigation of Fuel Spray Propagation, Combustion and Soot Formation/Oxidation in a Single Cylinder Medium Speed Diesel Engine

2012 ◽  
Author(s):  
Fridolin Unfug ◽  
Uwe Wagner ◽  
Kai W. Beck ◽  
Juergen Pfeil ◽  
Ulf Waldenmaier ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Speed ◽  
Liquid Fuel ◽  
Combustion Process ◽  
Fuel Spray ◽  
Soot Concentration ◽  
Single Cylinder ◽  
Medium Speed ◽  
532 Nm

To fulfil strict emission regulations and the need for higher efficiency of future Diesel engines require an optimized combustion process. Optical investigations represent a powerful tool for getting a better understanding of the ongoing processes. For medium speed Diesel engines, optical investigations are relatively rare or not available. The “Institut für Kolbenmaschinen” (IFKM) and MAN Diesel & Turbo SE performed extensive optical in-situ investigations of the injection and combustion process of a MAN 32/44 CR single cylinder medium speed Diesel engine that provide previously unavailable insights into the ongoing processes. The optical investigations aimed on fuel spray visualization, high-speed soot luminescence measurement and two colour pyrometry applied for five combustion chamber regions. To apply the optical measurement techniques, two optical accesses were designed. Access no. 1 is placed near the cylinder liner. Access no. 2 is located close to the injector in a 46° angle to the cylinder vertical axis. An insert was used which consists of an illumination port and a visualization endoscope. Additionally some special nozzle designs were used beside the standard nozzle, which have one separated nozzle hole. This enables a simultaneous view from both optical accesses on the same flame cone. For Mie-Scattering investigation a pulsed Nd:YAG-Laser with 532 nm wavelength was used for illumination and a CCD-camera with an upstream 532 nm optical filter was used for visualization. This combination allows observing the liquid fuel distribution even after start of combustion. Penetration depth of liquid fuel spray was analysed for different swirl numbers, intake manifold pressures, injection timings and injection pressures. High-speed flame visualization was done by two CMOS cameras which were mounted at two different optical accesses with view on the same flame cone. Due to this application a simultaneous measurement of the flame distribution of two different views was possible. This enables a 3-dimensional investigation of the flame propagation process. In addition, the advanced two colour pyrometry was applied for five different regions of the same flame cone. Due to a calibration after each measurement the absolute radiant flux can be calculated and thus the absolute temperature and soot concentration. With this procedure it was possible to give a real temperature and soot concentration distribution of the flame cone. To provide more detailed information about the combustion process, selected engine operation points were simulated with a modified version of the CFD code KIVA3v-Release2 at the IFKM. The simulated results were compared to the measured data.

Experimental Stand to Investigate the Injection Process in Diesel Engines

2021 ◽  
Vol 42 ◽  
pp. 79-84
Author(s):  
Dragoș Tutunea ◽  
Ilie Dumitru ◽  
Laurenţiu Racilă
Keyword(s):  
Diesel Engines ◽  
Electric Motor ◽  
High Performance ◽  
Fuel Injection ◽  
Combustion Process ◽  
Injection Pressure ◽  
Injection System ◽  
Injection Process ◽  
Experimental Stand ◽  
Fuel Injection Pressure

The objective of this paper is to investigate the fuel injection system in diesel engines by using inline pumps. In a diesel engines, the fuel injection pressure plays an important role in the combustion process in order to obtain high performance and low fuel consumption. The experiments in this paper are been performed on a 6 cylinder inline pump which is actioned by an electric motor with variable r.p.m.-s The quantity of the fuel injected by each injector is measured function of time and the speed of electric motor. The experiments show the degree of non-uniformity of the fuel delivered by the pump to injectors.

Application of HFRT Methods to Diagnose the Technical Condition of High-Speed Marine Diesel Engines

2015 ◽  
Vol 236 ◽  
pp. 161-168
Author(s):  
Tomasz Lus
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Technical Condition ◽  
Injection System ◽  
Engine Fuel ◽  
Naval Academy ◽  
Marine Diesel

The paper presents problems related to testing of the technical condition of high-speed marine diesel engines that are not equipped with indicated valves, as it is in the case of larger medium-and low-speed marine internal combustion engines. In this case, in assessment of technical condition of engine fuel injection system and valve gear system a vibration signals (in time / angle domain) analysis modified method called HFRT (High Frequency Resonance Technique) can be used. This method indirectly helps also to evaluate the fuel combustion process in the engine cylinders. The paper presents the theoretical basis of a modified HFRT method, physical implementation of the marine diesel engine system’s analyzer used for marine engines testing built at the Institute of Construction and Operation of Ships at Polish Naval Academy (PNA) in Gdynia. The paper also includes a description of the vibration signal processing methodology and examples of measurements made in the ships conditions for a few selected types of engines.

Penetration and Vaporization of Diesel Fuel Sprays

1969 ◽  
Vol 184 (10) ◽  
pp. 147-170 ◽  
Author(s):  
R. Burt ◽  
K. A. Troth
Keyword(s):  
Combustion Chamber ◽  
Diesel Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Major Effect ◽  
Engine Fuel ◽  
Liquid Droplets ◽  
Fuel Sprays ◽  
Air Movement ◽  
Air Mixing

In the diesel engine, fuel is injected into the hot, compressed air in the combustion chamber. Thus the process of diesel combustion is essentially inhomogeneous, and the mixing of the fuel and air in the combustion chamber dominates the whole combustion process. Since fuel–air mixing is so important the distribution of the injected fuel has a major effect on combustion performance. This is particularly true of direct-injection diesel engines which have relatively low rates of air movement. In all diesel engines, fuel is injected into the combustion chamber at high pressure through small nozzles. The high-velocity liquid jet atomizes, after emerging from the nozzle, into a spray of liquid droplets. The penetration, distribution, and vaporization of the sprays, together with the air movement, govern the mixing of fuel and air. The penetration of fuel sprays is dealt with in Part 1 of the paper; Part 2 describes a study of the vaporization of fuel sprays.

scholarly journals Analysis of the repeatability of fuel spray indexes in a spray-guided direct-injection spark-ignition engine

2016 ◽  
Vol 164 (1) ◽  
pp. 49-55
Author(s):  
Ireneusz PIELECHA
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition Engine ◽  
Fuel Spray ◽  
Injection Duration ◽  
Cylinder Test ◽  
Direct Injection Spark Ignition ◽  
Spray Velocity ◽  
Made In

The development and research works on liquid fuel injection in spark-ignited direct injection (SIDI) engines, apart from so common in recent years simulation methods, still have a significant cognitive substrate. This is related to experimental research on repeatability of combustion process using multi- and mono-cylinder test engines and Rapid Compression Machines. The repeatability of preparation and delivery processes has immediate impact on repeatability of combustion process. Except for the necessity of obtaining the repeatability of fuel amounts, the repeatability of injected fuel spray is required. The penetration range and spray area in combustion chamber have direct impact on mixture creation and formation. The optical research on fuel injection has been made in order to determinate its repeatability. The research on unrepeatability of fuel spray propagation has been conducted using piezoelectric injectors of outward-opening type, being primary elements of the spray-guided combustion systems. The results of research were presented in the form of index of variation of the selected parameters. The evaluation of the results of the optical research concerns radial spray penetration and fuel spray velocity. Unrepeatability has been presented with coefficient of variation of radial penetration in relation to the time of injection duration. It has been observed that the coefficients of various parameters are lower with longer times of fuel injection.

scholarly journals Tribology in Marine Diesel Engines

2021 ◽  
Author(s):  
Sung-Ho Hong
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Tribological Performance ◽  
Engine Room ◽  
Medium Speed ◽  
Marine Engines ◽  
Marine Diesel ◽  
Power Outputs ◽  
Engine Components

This chapter deals with the tribology of marine diesel engines. Several types of diesel engines have been installed and used in the engine room of marine ships. Some of them, used for propulsion, operate at low-speed in a two-stroke combustion process in conjunction with propellers. Four-stroke engines are used for power generation and operates at medium-speed. In general, two or more four-stroke engines, including spares, are installed in the large ships. Tribological problems are important issue in the respect of reliability in the marine diesel engines, and there are many tribological engine components including bearings, pistons, fuel injection pumps and rollers. Moreover, the marine engines have lubricant problems such as lacquering. Improvements to the tribological performance of marine engine components, and lubricants can provide reduced oil and fuel consumption, improved durability, increased engines power outputs and maintenance. Therefore, this chapter shows better designs and methods in order to improve the tribological problem in the marine diesel engines.

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