Numerical Simulation of the Dynamic Response of a Diesel Fuel Injector Using CFD

2005 ◽  
Author(s):  
Yong Yi ◽  
Aleksandra Egelja ◽  
Clement J. Sung
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Dynamic Response ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Fuel Injector ◽  
Diesel Fuel Injection ◽  
Very High

The development of a very high pressure diesel fuel injection system has been one of the key solutions to improve engine performance and to reduce emissions. The diesel fuel management in the injector directly affects how the fuel spray is delivered to the combustion chamber, and therefore affects the mixing, combustion and the pollutants formation. To design such a very high pressure diesel fuel injection system, an advanced CFD tool to predict the complex flow in the fuel injection system is required in the robust design process. In this paper, a novel 3D CFD dynamic mesh with cavitation model is developed to simulate the dynamic response of the needle motion of a diesel fuel injector corresponding to high common rail pressure and other dimensional design variables, coupling with the imbalance of the spring force and the flow force (pressure plus viscous force). A mixture model is used for cavitation resulting from high speed flow in fuel injector. Due to the lack of experimental data, the model presented in this paper is only validated by a limited set of experimental data. Required meshing strategy is also discussed in the paper.

Development of cavitation and enhanced injector models for diesel fuel injection system simulation

2002 ◽  
Vol 216 (7) ◽  
pp. 607-618 ◽  
Author(s):  
H-K Lee ◽  
M F Russell ◽  
C S Bae ◽  
H D Shin
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Injection System ◽  
Fuel Injection System ◽  
Non Linear ◽  
Diesel Fuel Injection ◽  
Injection Pressures

To expedite the application of fuel injection equipment to diesel engines, powertrain engineers are simulating the rate of injection with computer models. Many of the simple models give quite substantial errors if fuel cavitation in the high pressure system and the variations in bulk modulus with temperature and pressure are not included. This paper discuses cavitation and a companion paper discusses the treatment of non-linear bulk modulus. Diesel fuel injection nozzle hole size has been reduced and the injection pressures have been raised, to improve combustion, and the termination of the injection has been accelerated, to reduce carbon particle mass in the exhaust. High injection pressures and rapid termination set up very large hydraulic waves in the pipes and drillings of the fuel injection system, be it pump-pipe-nozzle or accumulator/common rail in type. The fuel momentum generated in these vigorous wave actions leaves such low pressures in parts of the system that vapour bubbles form in the fuel. Cavitation changes the bulk modulus of the fuel and the collapse of the cavities imparts sudden high pressure pulses to the fuel columns in the system and changes injection characteristics significantly. When modelling devices to control injection rate, the cavitation and non-linear bulk modulus have to be incorporated into the model. To this end, the concept of ‘condensation’ has been useful. The cavitated pipe section is divided into liquid and liquid + vapour mixture columns and modified momentum and mass conservation equations are applied separately. The model has been validated with a particular application of a rotary distributor pump to a high speed direct injection diesel engine, which is one of the more difficult fuel injection systems to model in which cavitation occurs at several operating conditions. The simulation results show the cavitation characteristics very well. This cavitated flow calculation model may be applied to other one-dimensional flow systems In addition, a more comprehensive injector model is introduced, which considers two loss factors at the needle seat and holes, sac volume, and viscous drag and leakage. This enhanced injector model shows some improvement at low load conditions

scholarly journals Exploiting Bayesian networks for fault isolation: A diagnostic case study of diesel fuel injection system

2019 ◽  
Vol 86 ◽  
pp. 276-286 ◽  
Author(s):  
Jinxin Wang ◽  
Zhongwei Wang ◽  
Viacheslav Stetsyuk ◽  
Xiuzhen Ma ◽  
Fengshou Gu ◽  
...  
Keyword(s):  
Bayesian Networks ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Fault Isolation ◽  
Injection System ◽  
Fuel Injection System ◽  
Diesel Fuel Injection

A Procedure for Upgrading an Electronic Control Diesel Fuel Injection System by Considering Several Engine Operating Regimes Simultaneously

1999 ◽  
Vol 121 (1) ◽  
pp. 159-165 ◽  
Author(s):  
B. Kegl
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection System ◽  
Fuel Injection System ◽  
Electronic Control ◽  
Control Parameters ◽  
Design Variables ◽  
Cam Profile ◽  
Diesel Fuel Injection ◽  
Operating Regimes

This paper describes an optimal design procedure for improving the injection rate histories of an electronic control diesel fuel injection system (ECD-FIS) with sleeve-timing-controlled pump. The research objective was to develop an approach for upgrading an existing ECD-FIS by performing only some low-cost modifications on its design. Therefore, the design variables are related to a relative small number of geometrical and control parameters of the injection system. The geometrical parameters influence only the shape of a rational Be´zier curve, representing the cam profile of the pump. The control parameters influence the injection timing and injection quantity. These control parameters are introduced into the set of design variables in order to enable good results over the whole engine operating regime. The design problem is formulated in a form of a non-linear problem of mathematical programming. Several operating regimes are simultaneously taken into account by an appropriate objective function while some geometrical properties of the cam profile as well as some injection parameters are kept within acceptable limits by the imposed constraints. The theory is illustrated with a numerical example.

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