Multidimensional Modeling of Impinging Sprays on the Wall in Diesel Engines

1999 ◽  
Vol 52 (4) ◽  
pp. 119-138 ◽  
Author(s):  
J. Senda ◽  
H. G. Fujimoto
Keyword(s):  
Diesel Engines ◽  
Formation Process ◽  
Fuel Injection ◽  
Soot Formation ◽  
Film Formation ◽  
Combustion Process ◽  
Interaction Process ◽  
Droplet Breakup ◽  
Wall Surface ◽  
Wall Interaction

This article summarizes model analysis of the dispersion process of a Diesel spray on the wall surface in order to simulate the spray-wall interaction process in Diesel engines. The mixture formation process near the wall of the piston cavity affects the combustion process and the hydrocarbon or soot formation process through the quenching of the mixture and flame at the wall surface. In particular, mixture burning occurs mainly near the cavity wall through the whole combustion period in the case of high pressure fuel injection. In this article, representative modeling approaches on spray-wall interaction process including the film flow formation are summarized briefly. Then, our models of spray impingement for low/high-temperature models including the process of fuel film formation, film breakup, wall-drop/film heat transfer, and droplet breakup owing to the solid-liquid interface boiling are introduced with the comparison of experimental results. This review article includes 83 references.

scholarly journals Possibilities of Simultaneous In-Cylinder Reduction of Soot andNOxEmissions for Diesel Engines with Direct Injection

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
U. Wagner ◽  
P. Eckert ◽  
U. Spicher
Keyword(s):  
Nitrogen Oxide ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Soot Formation ◽  
Soot Oxidation ◽  
The Other ◽  
Injection System ◽  
Nitrogen Oxide Emissions ◽  
Injection Strategy ◽  
Soot Emissions

Up to now, diesel engines with direct fuel injection are the propulsion systems with the highest efficiency for mobile applications. Future targets in reducingCO2-emissions with regard to global warming effects can be met with the help of these engines. A major disadvantage of diesel engines is the high soot and nitrogen oxide emissions which cannot be reduced completely with only engine measures today. The present paper describes two different possibilities for the simultaneous in-cylinder reduction of soot and nitrogen oxide emissions. One possibility is the optimization of the injection process with a new injection strategy the other one is the use of water diesel emulsions with the conventional injection system. The new injection strategy for this experimental part of the study overcomes the problem of increased soot emissions with pilot injection by separating the injections spatially and therefore on the one hand reduces the soot formation during the early stages of the combustion and on the other hand increases the soot oxidation later during the combustion. Another method to reduce the emissions is the introduction of water into the combustion chamber. Emulsions of water and fuel offer the potential to simultaneously reduceNOxand soot emissions while maintaining a high-thermal efficiency. This article presents a theoretical investigation of the use of fuel-water emulsions in DI-Diesel engines. The numerical simulations are carried out with the 3D-CFD code KIVA3V. The use of different water diesel emulsions is investigated and assessed with the numerical model.

Effects of Fuel Quantity on Soot Formation Process for Biomass-Based Renewable Diesel Fuel Combustion

2016 ◽  
Author(s):  
Wei Jing ◽  
Zengyang Wu ◽  
William L. Roberts ◽  
Tiegang Fang
Keyword(s):  
Diesel Fuel ◽  
Formation Process ◽  
Fuel Injection ◽  
Soot Formation ◽  
Injection Pressure ◽  
Soot Temperature ◽  
Renewable Diesel ◽  
Constant Volume Combustion Chamber ◽  
Kl Factor ◽  
Soot Measurement

Soot formation process was investigated for biomass-based renewable diesel fuel, such as biomass to liquid (BTL), and conventional diesel combustion under varied fuel quantities injected into a constant volume combustion chamber. Soot measurement was implemented by two-color pyrometry under quiescent type diesel engine conditions (1000 K and 21% O2 concentration). Different fuel quantities, which correspond to different injection widths from 0.5 ms to 2 ms under constant injection pressure (1000 bar), were used to simulate different loads in engines. For a given fuel, soot temperature and KL factor show a different trend at initial stage for different fuel quantities, where a higher soot temperature can be found in a small fuel quantity case but a higher KL factor is observed in a large fuel quantity case generally. Another difference occurs at the end of combustion due to the termination of fuel injection. Additionally, BTL flame has a lower soot temperature, especially under a larger fuel quantity (2 ms injection width). Meanwhile, average soot level is lower for BTL flame, especially under a lower fuel quantity (0.5 ms injection width). BTL shows an overall low sooting behavior with low soot temperature compared to diesel, however, trade-off between soot level and soot temperature needs to be carefully selected when different loads are used.

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.

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.

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.

CFD Analysis of the Scavenging Process in Marine Two-Stroke Diesel Engines

2014 ◽  
Author(s):  
Fredrik H. Andersen ◽  
Johan Hult ◽  
Karl-Johan Nogenmyr ◽  
Stefan Mayer
Keyword(s):  
Diesel Engines ◽  
Axial Velocity ◽  
Fuel Injection ◽  
Vortex Breakdown ◽  
Combustion Engine ◽  
Combustion Process ◽  
Tangential Velocity ◽  
Engine Performance ◽  
Adverse Pressure Gradient ◽  
Bottom Dead Center

The scavenging process is an integral part of any two-stroke internal combustion engine regardless of being spark ignited (SI) or compression ignited (CI). The scavenging process is responsible for replacing the burned gas from the combustion process from the previous working stroke with fresh air/charge before the subsequent compression stroke. This implies that the scavenging process is integral to engine performance as it influence the initial condition for the combustion process, thus affecting the fuel economy, power output and emission of hazardous gases. Two-stroke diesel engines for marine propulsion normally operates by the uniflow scavenging method, where the scavenge air enters the cylinder via inlet ports located near the bottom dead center and exits through one or several exhaust valves located in the cylinder head. This arrangement concentrates the airflow in one direction through the cylinder thus giving the method its name. The inlet ports are angled with respect to the local radius which will introduce a tangential velocity component to the air flow. The air moves axially through the cylinder in a swirling motion that favors mixing of fuel and air as the injected fuel is transported with the swirling air in the combustion chamber during fuel injection. A known characteristic of swirling flows is an adverse pressure gradient in the center of the rotating flow which might lead to a local deficit in axial velocity and the formation of central recirculation zones, known as vortex breakdown. Optimal scavenging is achieved when the gas exchange is done by displacement, the local deficit in axial velocity will increase the mixing of burned gas and scavenge air thus decreasing the amount of pure displacement.

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.

scholarly journals Analysis of the market structure of long-distance transport vehicles in the context of retrofitting diesel engines with modern dual-fuel systems.

2021 ◽  
Author(s):  
Janusz Chojnowski ◽  
Mirosław Karczewski
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Common Rail System ◽  
Long Distance ◽  
Long Distance Transport ◽  
Gas Standards ◽  
Reliable Solution

The demands placed on vehicles are constantly increasing. European legislation has forced commercial vehicle manufacturers to develop ever more powerful and dynamic engines with low fuel consumption. With the appearance of exhaust gas standards, truck manufacturers realized that it was necessary to improve the fuel supply system so that the combustion process was more efficient. To achieve this the fuel injected into the cylinders had to be finer in order to mix more easily with air. High-pressure unit injection systems have proved to be a good and reliable solution. They are also relatively cheap to produce and less prone to fuel contamination. Many years and millions of failure-free kilometers traveled on unit injectors effectively distracted some users and producers from the Common Rail system. Exhaust gas standards and increasing consumer expectations forced manufacturers to take another step in their development, i.e. the need for more precise fuel injection control. The injectors had to run faster in order to carry out the initiation dose, the actual injection and the extra injection. All these modifications make diesel engines in commercial vehicles such as tractor units much more powerful. They also allow for cooperation with aftermarket dual-fuel CNG-ON and LPG-ON installations. Dual-fuel solutions are perhaps another step towards reducing emissions, and thanks to reduced tolls, they are becoming a real alternative to conventional fuel-powered tractor units. This work focuses on the structure of the truck tractor market in terms of selecting cars used for the use of a non-factory dual-fuel CNG-ON installation.

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