The Role of Simulation in the Development of a Fast-Actuation Solenoid C.R. Injection System

2004 ◽  
Author(s):  
Gian Marco Bianchi ◽  
Piero Pelloni ◽  
Giovanni Osbat ◽  
Marco Parotto ◽  
Rita Di Gioia ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Linear Analysis ◽  
Operating Conditions ◽  
System Model ◽  
Injection System ◽  
Multiple Injection ◽  
Pressure Regulator

Upcoming Euro 4 and Euro 5 emission standards are increasing efforts on injection system developments in order to improve mixture quality and combustion efficiency. The target features of advanced injection system are related to their capability of operating multiple injection with a precise control of amount of fuel injected, low cycle-by-cycle variability and life drift, within flexible strategies. In order to accomplish this task, performance must be optimised since injection system concept development by acting on. The extensive use of numerical approach has been identified as a necessary integration to experiments in order to put on the market high quality injection system accomplishing strict engine control strategies. The modelling approach allows focusing the experimental campaign only on critical issues saving time and costs, furthermore it is possible to deeply understand inner phenomena that cannot be measured. The lump/ID model of the whole system built into the AMESim® code was presented in previous works: particular attention was devoted in the simulation of the electromagnetic circuits, actual fluid-dynamic forces acting on needle surfaces and discharge coefficients, evaluated by means 3D-CFD simulations. In order to assess new injection system dynamic response under multiple injection strategies reproducing actual engine operating conditions it is necessary to find to proper model settings. In this work the integration between the injector and the system model, which comprehends the pump, the pressure regulator, the rail and the connecting-pipes, will be presented. For reproducing the dynamic response of he whole system will be followed a step-by-step approach in order to prevent modelling inaccuracies. Firstly will be presented the linear analysis results performed in order to find injection system own natural frequencies. Secondly based on linear analysis results will be found proper injection system model settings for predicting dynamic response to external excitations, such as pump perturbations, pressure regulator dynamics and injection pulses. Thirdly experimental results in terms of instantaneous flow rate and integrated injected volume for different operating conditions will be presented in order to highlight the capability of the modelling methodology in addressing the new injection system design.

Engine Torque Non-Uniformity Evaluation Using Instantaneous Crankshaft Speed Signal

2001 ◽  
Author(s):  
Nicolò Cavina ◽  
Fabrizio Ponti
Keyword(s):  
Engine Speed ◽  
Combustion Engine ◽  
Control Strategies ◽  
Ignition Time ◽  
Operating Conditions ◽  
Injection System ◽  
Engine Torque ◽  
Production Variability ◽  
The One ◽  
Speed Fluctuations

Abstract The paper presents the development of a methodology for evaluating the torque non-uniformity between the various cylinders of an Internal Combustion Engine (ICE). This non-uniformity can be due, for example, to pathological operating conditions such as misfires or misfuels, as well as to other abnormal operating conditions. Between the nominal torque production and the one corresponding to the absence of combustion there exist, in fact, a series of possible intermediate conditions. Each of them corresponds to a value of produced torque that lies between the nominal value and the one corresponding to the lack of combustion (due for example to statistical dispersion in manufacturing or aging in the injection system). The diagnosis of this type of non-uniformity is a very important issue in today’s engine control strategies design. The use of the developed methodology should in fact allow the control strategy to adopt the appropriate interventions if the diagnosed non-uniformity is related to different behavior of the injectors. In order to evaluate this torque production variability between the various cylinders, information hidden in the instantaneous crankshaft speed fluctuations has been processed using a suitable methodology. The procedure has been validated running a supercharged 2.0 liters V6 engine, and a 1.2 liters L4 engine, in a test cell. During the tests, the in-cylinder pressure signal has been acquired together with the instantaneous engine speed, in order to determine a correlation between speed fluctuations and the indicated torque produced by each cylinder. The actual cylinder by cylinder torque non-uniformity can then be evaluated on-board by processing engine speed. The procedure is able to diagnose the absence of combustion (due for example to a misfire or a misfuel) as well as abnormal combustions that do not necessarily involve lack of combustion, with the accuracy needed for on-board use. Control interventions to injection and ignition time commands of one or more cylinders should in most cases be able to re-establish torque production uniformity.

Combined Experimental - Numerical Approach for the Fuel Jet Study in a LPP Combustor

2011 ◽  
Author(s):  
Amedeo Amoresano ◽  
Maria Cristina Cameretti ◽  
Raffaele Tuccillo
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Experimental Information ◽  
Liquid Fuels ◽  
Injection System ◽  
Spray Parameters ◽  
Flow Solver ◽  
Fuel Jet ◽  
Fuel Vapour

The purpose of the paper is the investigation of the phenomena that mainly affect the mixture preparation and the combustion development in lean-premixed chambers supplied with liquid fuels (LPP). In such a study, the experimental analysis, performed by PDA based measurements, is supported and addressed by a CFD tool that is able to simulate the injection conditions, by isolating and studying some specific phenomena. A 3-D fluid dynamic code (i.e., the FLUENT® flow solver) has been used to simulate the spray pattern in the chamber. Preliminarily, the numerical simulation refer to cold flow conditions, in order to validate the estimation of the fundamental spray parameters through the comparison with the experimental data; in a second step, the calculations employ boundary conditions close to those occurring in the actual combustor operation, in order to predict the fuel vapour distribution throughout the premixing chamber. In particular, the fuel is injected under the typical conditions that occur in the injection system of a gas turbine LPP combustor. In this phase, the experimental information are introduced in terms of air and fuel mass flow rates and of inlet characteristics of the air flow entering the prevaporizing chamber, in order to predict the fuel vapour formation and distribution. The paper also compares different approaches that have been experienced for the CFD simulation.

Engine Torque Nonuniformity Evaluation Using Instantaneous Crankshaft Speed Signal

2003 ◽  
Vol 125 (4) ◽  
pp. 1050-1058 ◽  
Author(s):  
N. Cavina ◽  
F. Ponti
Keyword(s):  
Engine Speed ◽  
Combustion Engine ◽  
Control Strategies ◽  
Ignition Time ◽  
Operating Conditions ◽  
Injection System ◽  
Engine Torque ◽  
Production Variability ◽  
The One ◽  
Speed Fluctuations

The paper presents the development of a methodology for evaluating the torque nonuniformity between the various cylinders of an internal combustion engine (ICE). This nonuniformity can be due, for example, to pathological operating conditions such as misfires or misfuels, as well as to other abnormal operating conditions. Between the nominal torque production and the one corresponding to the absence of combustion there exist, in fact, a series of possible intermediate conditions. Each of them corresponds to a value of produced torque that lies between the nominal value and the one corresponding to the lack of combustion (due for example to statistical dispersion in manufacturing or aging in the injection system). The diagnosis of this type of nonuniformity is a very important issue in today’s engine control strategies design. The use of the developed methodology should in fact allow the control strategy to adopt the appropriate interventions if the diagnosed nonuniformity is related to different behavior of the injectors. In order to evaluate this torque production variability between the various cylinders, information hidden in the instantaneous crankshaft speed fluctuations has been processed using a suitable methodology. The procedure has been validated running a supercharged 2.0 liters V6 engine, and a 1.2 liters L4 engine, in a test cell. During the tests, the in-cylinder pressure signal has been acquired together with the instantaneous engine speed, in order to determine a correlation between speed fluctuations and the indicated torque produced by each cylinder. The actual cylinder-by-cylinder torque nonuniformity can then be evaluated on-board by processing engine speed. The procedure is able to diagnose the absence of combustion (due for example to a misfire or a misfuel) as well as abnormal combustions that do not necessarily involve lack of combustion, with, the accuracy needed for on-board use. Control interventions to injection and ignition time commands of one or more cylinders should, in most cases, be able to re-establish torque production uniformity.

Analysis of a 6 Cylinder Turbocharged HCCI Engine Using a Detailed Kinetic Mechanism

2002 ◽  
Author(s):  
Giuseppe Cantore ◽  
Luca Montorsi ◽  
Fabian Mauss ◽  
Per Amne´us ◽  
Olof Erlandsson ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Operating Conditions ◽  
Engine Control ◽  
Gas Composition ◽  
Time Step ◽  
Hcci Engine ◽  
Power Code

When analyzing HCCI combustion engine behavior, the integration of experimental tests and numerical simulations is crucial. Investigations of possible engine control strategies as a function of the different operating conditions have to take the behavior of the whole HCCI engine into account, including the effects both of the combustion process and of complex devices. Therefore the numerical simulation code must be able both to model accurately the gas-dynamic of the system and to evaluate the combustion chemical kinetics. This paper focuses on the coupling between the commercial one-dimensional fluid-dynamic GT-Power Code and our in-house detailed chemical kinetic Ignition Code. An interface has been developed in order to exchange information between the two codes: the Ignition Code considers as boundary conditions the GT-Power Code values provided for the gas composition at IVC and the pressure and temperature at every time step and passes back to GT-Power the burnt fuel fraction and stores in an external file the in cylinder gas composition. Thus the whole engine cycle can be accurately simulated, estimating the interactions between the gas-dynamics phenomena along the intake and exhaust pipes and through the valves, and the chemical processes occurring during the closed valves period. This tool makes it possible to analyze the engine behavior under duty cycle operating conditions, and therefore it represents a useful support to the experimental measurements, reducing the number of tests required to assess the proper engine control strategies.

Analysis of a Double Inlet Gerotor Pump: A Dynamic Multi-Phase CFD Approach Accounting for the Fluid Compressibility and Temperature Dependent Properties

2019 ◽  
Author(s):  
Massimo Milani ◽  
Luca Montorsi ◽  
Stefano Terzi ◽  
Gabriele Storchi ◽  
Andrea Lucchi
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Bubble Formation ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Gerotor Pump ◽  
Fluid Properties ◽  
Intake Pressure ◽  
Multi Phase

Abstract The paper analyzes the fluid dynamic performance of a double inlet Gerotor pump by means of a multi-phase and multicomponent CFD approach. The numerical simulation includes the full 3D geometry of the pump as well as the real physics of the compressible hydraulic fluid and the rotating dynamic motion. The aeration and cavitation phenomena are included in the analysis adopting the Rayleight-Plesset equation and inertia controlled growth model for bubble formation. Cavitation and aeration phenomena are detected, especially when intake pressure is lower than atmospheric pressure. The influence of the fluid temperature variation on the component performance is also numerically predicted. The accuracy of a detailed modelling of the fluid properties variation with respect to the temperature and pressure is addressed and the effects on the numerical results is investigated. The rotational speeds of the internal and the external gears of the pump and the engagement between the teeth are addressed by means of an overset mesh approach. Constant leak height is considered between the gears and the case, while the overset mesh approach is adopted in order to accurately predict the leakage due to the teeth engagement. This numerical approach enables to investigate the dynamic performance of Gerotor gear pumps in terms of flow rate and pressure ripples and volumetric efficiency under standard and critical (actual) operating conditions. Good agreement between numerical and experimental results was found for specific operating conditions.

scholarly journals Theoretical and experimental control strategies assessment of a Sliding Vane Oil Pump

2020 ◽  
Vol 197 ◽  
pp. 06022
Author(s):  
Fabio Fatigati ◽  
Marco Di Bartolomeo ◽  
Giuseppe Lo Biundo ◽  
Francesco Pallante ◽  
Roberto Cipollone
Keyword(s):  
High Efficiency ◽  
Combustion Engine ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Rate Variation ◽  
Vane Pump ◽  
Oil Flow ◽  
Pros And Cons ◽  
Virtual Platform

To date, Sliding Vane Pump (SVP) technology is one of the most attractive solution in different technical applications thanks to its reliability and compactness and capability to keep a high efficiency even when it is working far from rated condition. In particular, this feature makes the SVP suitable to be employed for the oil circulation (SVOP) in Internal Combustion Engine (ICE) which is characterized by a wide oil flow rates variation, delivered pressure and temperature variation which causes operating conditions of the pump far from the design point. Flow delivered changes in these machines are produced by varying the eccentricity for a mechanical connection with the engine - or by varying the speed of revolution. The mild hybridization of the powertrains calls for a strong development of electrically assisted engine auxiliaries which undoubtedly makes the flow variations easier to be done, but the presence of an electric motor requires some technological choices not fully assessed, a cost increase and a reliability decrease. The paper presents a mathematical model of a SVOP for oil circulation in ICE, suitably validated by a wide experimental activity. The model integrates a mono and zero-dimensional fluid-dynamic analysis and allows to represent the intimate behaviour of the machine. Moreover, it was employed as virtual platform to discuss pros and cons of different flow rate variation strategies and their effect on the efficiency of the SVOP.

Experimental Investigation of Dynamics Effects on Multiple-Injection Common Rail System Performance

2005 ◽  
Author(s):  
A. E. Catania ◽  
A. Ferrari ◽  
M. Manno ◽  
E. Spessa
Keyword(s):  
Wave Propagation ◽  
Fluid Dynamic ◽  
Common Rail ◽  
Lumped Parameter Model ◽  
Injection System ◽  
Geometrical Parameters ◽  
System Control ◽  
Analysis Tool ◽  
Multiple Injection ◽  
Common Rail System

Fundamental aspects of Common Rail (C.R.) fuel-injection system dynamics were investigated, paying specific attention to the wave propagation induced pressure oscillations and to their relationships with the system control parameters and multiple-injection performance. A detailed experimental analysis of the pressure wave propagation phenomena in a last-generation C.R Multijet equipment of the solenoid type was carried out on a high performance new test bench Moehwald-Bosch MEP2000-CA4000 under real engine simulated conditions. The experimental results include pressure time-histories in the rail and at the injector inlet, as well as flow-rate patterns, for both single and multiple injection events. The measured volume of fuel injected on each injection pulse is also reported. The analysis of the system oscillating behavior was carried out with the support of a simple lumped parameter model. Such a model was shown to be capable of predicting the main frequencies of the hydraulic circuit and their dependence on the geometrical parameters. The good agreement between the outcome of this simple model and the experimental data also substantiated the reliable authors’ interpretation of the cause and effect main relations underlying the complex flow phenomena occurring in the system. A refined computational model was developed and validated in a parallel work ([9]), providing a hydrodynamic analysis tool complementary to experimentation and a means of hydraulic system layout design and optimization. Finally, the mutual fluid-dynamic interactions taking place between consecutive injection events by distinct injectors of the same system are investigated in addition to the difference in dynamics of VCO- and Minisac-nozzle injectors.

Fluid-Dynamic Characterization of a CNG Injection System

2012 ◽  
Author(s):  
Mirko Baratta ◽  
Daniela Misul ◽  
Ezio Spessa ◽  
Giuseppe Gazzilli ◽  
Andrea Gerini
Keyword(s):  
Mass Flow ◽  
Fluid Dynamic ◽  
Injection System ◽  
Rail Pressure ◽  
Dynamic Characterization ◽  
Pressure Regulator ◽  
Fuel Mass ◽  
Wide Range ◽  
The Impact

A renewed interest in CNG fuelled engines, which has recently been boosted by the even more stringent emissions regulations, has generated considerable R&D activity in the last few years. In order to fulfill such limits, most current CNG vehicles combine advanced technical and control solutions such as VVA intake systems, new turbocharging solutions, enhanced ECU strategies, etc. The present work focuses on the complete fluid-dynamic characterization of a gaseous injection system so as to support the design of the related control module and devices. To that end, a numerical investigation into the fluid-dynamic behavior of a commercial CNG injection system has been extensively carried out by means of the GT-POWER code. A detailed geometrical model including the rail, the injectors as well as the pipe connecting the pressure regulator to the rail has been built in the GT-POWER environment. The model has been validated by comparing the experimental to the numerical outputs for the rail pressure and for the injected mass quantity. The model has hence been applied to the prediction of the pressure waves produced by the injection event and of their effect on the actually injected fuel mass. Moreover, the influence of the pressure regulator dynamics has been assessed by simulating the impact on the system behavior of a pressure noise downstream from the regulator. Finally, the possibility of reducing the rail volume, thus enhancing its dynamic response, has been investigated. The results have shown a good agreement between the predicted and the measured rail pressure and injected fuel mass flow rates over a wide range of engine operation conditions. Moreover, the dynamic simulations sketched a dependence of the injected fuel mass on the average rail pressure level, which in turn appeared to reduce for increasing engine power outputs. Finally, the reduction in the rail volume has proved not to significantly affect the injected mass flow rate.

Numerical Study of SI Engine Part Load Operating Conditions Using Different VVA Strategies

2011 ◽  
Author(s):  
Michele Battistoni ◽  
Carlo N. Grimaldi ◽  
Francesco Mariani
Keyword(s):  
Numerical Study ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Load Control ◽  
Valve Closure ◽  
Intake Valve ◽  
Flamelet Model ◽  
Part Load ◽  
Engine Model

In SI engines, VVA (Variable Valve Actuation) technology is mainly used for the reduction of pumping losses at part load. This paper presents the results of fluid dynamic analyses on a 4V engine about the effects of different VVA strategies, by comparing and discussing the results in terms of organized charge motions, turbulence levels, flame developments, NO and CO emissions. CFD simulations cover five load control cases: comparison is among conventional throttling, EIVC (Early Intake Valve Closure) with symmetric and asymmetric intake lifts, LIVC (Late Intake Valve Closure) and symmetrical Multi-Lift strategies. 3D U-RANS simulations are performed, adopting the Extended Coherent Flamelet Model (ECFM) for the description of premixed SI combustion. The 3D model is also coupled to a 1D engine model which provides inlet/outlet boundary conditions. Simulation results highlight the potential of asymmetric Early Intake Valve Closure (EIVC) strategy which allows reducing pumping losses and, at the same time, achieving good turbulence intensity and combustion speed, if compared to other load control strategies. Multi-Lift strategy resulted excellent in terms of burn duration, but pumping losses are practically the same as in the throttled engine.

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