1,720,971 research outputs found
"Comparison of V10 and V12 F1 Engines"
No full textThe paper compares 3.0 liter F1 engines having different architectures and developed in compliance with the 1998 FIA technical regulations. Similarity rules and non dimensional parameters from previous projects define key geometry and operating parameters for V10 and V12 engines having equal degree of sophistication. The paper presents computed classical engine outputs versus engine speed, including brake, indicated and friction values. The V12 solution shows clear advantages in terms of pure engine performances
Experimental and Computational Methods for Swirl Port Design in Internal Combustion Engines
No full textThe paper reviews the minimum losses and intake flow conditioning criteria typically adopted for the design of swirl ports in two valve Direct Injection (DI) Diesel engines, as well as in some two valve Spark Ignition (SI) engines. The standard experimental practice, based on the use of steady flow discharge and swirl coefficients as a measure of port design quality is first presented. The analogous computational methodology, where the steady flow is simulated, is then introduced. The computational methodology is extensively validated against a data set for a series of ports, of the direct, hybrid and helical type. The computational methodology is finally applied to simulate the transient flow within the engine during the intake stroke. The computed Intake Valve Closure (IVC) flow field provides a more rational basis for port optimization than steady flow coefficients, even if these latter simulations have still to be properly validated
Experimental and theoretical analysis of a Diesel fuel injection system
No full textThe paper presents experimental and theoretical results obtained for a mechanical Diesel fuel injection system, made up of a distributor-type pump, four delivery pipes and four four-hole injectors. Pressure in the pumping chamber, in two locations along the fuel line and within the injector is measured directly, as well as the injector needle lift. The flow rate is evaluated through the measure of pressure in the injection chamber.Experimental results are sustained by theoretical results. The numerical model considers systems of ordinary differential equations representing the operation of injector, pump, delivery valve and line volume elements. Only a few model details are presented. Similar approaches are in use by many years, and the accuracy they provide is generally accepted to be fairly good. Theoretical and experimental results are presented vs. the time at different pump speeds, showing a very satisfactory accuracy.The main objective of the paper is to describe the unsteady flow within the injector, and to show differences with reference to the steady flow. Despite the subject is not adequately covered in the open literature, several reasons suggest that steady and unsteady flow behaviors differ considerably. These differences may affect the prediction of both injection pressure and flow rate
Experimental and Computational Analysis of a High Performance Motorcycle Engine
No full textA high performance, motorcycle engine is analyzed by using integrated experimental and computational methods. Test bench experiments provide a few gross engine performance parameters. Dynamic simulations provide gross engine performance parameters and a detailed description of basic phenomena. Modelling guidelines are briefly reviewed. The accuracy of the model is finally assessed through comparison of experimental and computational gross engine performance parameters
Numerical optimization of a racing engine with variable intake and exhaust geometry and valve actuation
No full textThis paper presents a numerical study on a racing engine with variable intake and exhaust geometry and valve actuation. The study is carried out by using dynamic engine simulations. Aim of the analysis is the evaluation of the benefits these devices have on engine performance. Results show clear advantages over the full range of engine speed
Numerical Correlation of Combustion Evolution and Port and Combustion Chamber Shape in a High Speed, Four Valve, Spark Ignition Engine
No full textThe paper presents the results of a CFD 1D and 3D analysis carried out on a high speed 4 valve 4-Stroke engine
Numerical Study of Volumetric Efficiencies in a High Speed, Four Valve, Four Cylinder, Spark Ignition Engine
No full textHigh power output, four stroke, motorcycle engines are characterised by specific power levels well beyond 150 HPllitre also in production engines. These power levels are obtained through extremely high values of volumetric efficiencies in tbe range of high engine speed, resulting from highly optimised gas exchange processes. In the present paper, a four cylinder, four valve per cylinder engine with a four-in-one exhaust is optimised for volumetric efficiencies by using state-of-the-artcomputational methods. These computational metbods include stati c three dimensional computations as well as dynamic one and three dimensional computations. The engine geornetric and operating parameters optimised by using these computations agree fairly well with those optimised by using experiments, thus demonstrating the effectiveness of the proposed computational practice
Influence of Intake Port Design on Permeability and Rate of Combustion in a Four Valve High Performance Engine
No full textThe paper presents some improvements to the design of the intake port and valve assembly of a new Ferrari 5.5 liter engine, in order to increase both permeability and rate of combustion. Design has been supported by CFD-3D simulations and experiments
Numerical Simulation of Turbulent Combustion in a Four Valve Spark Ignition Engine with CRI/Turbokiva 2.0 Code
No full textAn enhanced engineering version of the Los Alamos National Laboratory's Kiva 3 code, called CRI/Turbokiva 2.0, was applied to the study of the mean and turbulent flow field evolution during compression and combustion in a spark ignition engine. A kinetically influenced turbulent combustion model was formulated to overcome the limitations of the standard turbulent combustion model. Mean velocity, turbulence intensity and turbulent length scale results are presented and compared with experimental data, providing satisfactory agreement. These comparisons provide a proper validation work for the fluid dynamic and combustion parts of the code
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