In your profession, an educated understanding of internal combustion engines is required, not optional. This two-day technology survey seminar covers the most relevant topics - ranging from the chemistry of combustion to the kinematics of internal components of the modern internal combustion engine - for maximum comprehension. Attendees will gain a practical, hands-on approach to the basics of the most common designs of internal combustion engines, as they apply to the gaseous cycles, thermodynamics and heat transfer to the major components, and the design theories that embody these concepts.
Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted.
With the actual tendency of space exploration, hypersonic flight have gain a significant relevance, taking the attention of many researchers over the world. This work aims to present a numerical tool to solve hypersonic gas dynamic flows for space propulsion geometries. This will be done by validating the code using two well-known hypersonic test cases, the double cone and the hollow cylinder flare. These test cases are part of NATO Research and Technology Organization Working Group 10 validation of hypersonic flight for laminar viscous-inviscid interactions. During the validation process several important flow features of hypersonic flow are captured and compared with available CFD and numerical data. Special attention is taken to the phenomenon of vibrational excitation of the molecules. Different vibrational non-equilibrium models are used and compared with the available data. The pressure and the heat flux along the surfaces are also analyzed.
Today’s frenetic engine manufacturing and transportation sector and its related traces viz; noise and vibration of our modern societies has adverse effect on environment as well as all of us. Generally, vehicle extensively tested to withstand against mechanical shocks, noise, vibration etc. While, accordingly make the provision such as suspension, dampers, air bags etc. still the problem of noise/vibration day-by-day incrementally arise and become severe with the age of vehicles. Noise/vibration is a controllable pollutant that deserves the attention were all the scientific community work hard for controlling their harmful effects. Modern research affords us the opportunity to understand the subject better and to develop advance technologies. Widely immediate slogan and goal of all industries might be to reduce Noise/vibration on predominantly basis while, make the quietest and smoothest running Engines.
Accurate and fast positioning of large aircraft component is of great importance for Automated Alignment System. The Ball joint is a widely-used mechanical device connecting the aircraft component and Automated Alignment System. However, there are some shortcomings for the device in man-machine engineering, such as the entry state of the ball-head still needs to be confirmed by the workers and then switched to the locking state manually. To solve above problems, a new positioning mechanism is present in this paper, which consists of a ball-head and a ball-socket. The new device is equipped with a monocular vision system, in which a calibrated industrial camera is used to collect the images of the ball-head. And then, the 3-D coordinate of the ball-head center is calculated by a designed algorithm, which combines the symmetry of the sphere and the principle of projection transformation, guiding the positioner to capture the ball-head.
The need to control emissions and maintain fuel economy is driving the use of advanced turbocharging technology in both diesel and gasoline engines. As the use of diesel engines in passenger car gasoline and diesel engines increases, a greater focus on advanced turbocharging technology is emerging in an effort to reap the benefits obtained from turbocharging and engine downsizing. This seminar covers the basic concepts of turbocharging of gasoline and diesel engines (light and heavy duty), including turbocharger matching and charge air and EGR cooling, as well as associated controls.
The advent of digital computers and the availability of ever cheaper and faster micro processors have brought a tremendous amount of control system applications to the automotive industry in the last two decades. From engine and transmission systems, to virtually all chassis subsystems (brakes, suspensions, and steering), some level of computer control is present. Control systems theory is also being applied to comfort systems such as climate control and safety systems such as cruise control or collision mitigation systems.
Driven by high fuel prices, environmental regulations, and consumer demand, the market for hybrid electric vehicles (HEV) has experienced rapid growth. Every major automotive company produces an HEV. There are approximately fifty different HEV models on the market and over eight million HEVs already sold. In order to meet current and future demands in the HEV and PHEV markets, success will depend on engineering personnel knowing how to develop and manufacture HEV powertrains. This two day seminar will cover the fundamentals of HEV powertrain design.
In partially premixed combustion engines high octane number fuels are injected into the cylinder during the late part of the compression cycle, giving the fuel and oxidizer enough time to mix into a desirable stratified mixture. If ignited by auto-ignition such a gas composition can react in an ignition wave-front dominated combustion mode. 3D-CFD modeling of such a combustion mode is challenging as the reaction speed is dependent on both mixing history and turbulence acting on the reaction wave. This paper presents a large eddy simulation (LES) study of the effects of energetic turbulence scale on the fuel/air mixing and on the propagation of reaction wave. The results are compared with optical experiments to validate both pressure trace and ignition location. The studied case is a closed cycle simulation of a single cylinder of a Scania D13 engine running PRF81 (81% iso-octane and 19% n-heptane).
The 2014 change in Formula 1 power units, from naturally aspirated to highly-downsized and heavily-boosted hybridized power units led to a relevant increase of the internal combustion engine brake specific power output in comparison with former V-8 units. The newly designed “down-sized” engines are characterized by a fuel flow limitation and relevant increase in the thermal loads acting on the engine components, in particular on those facing the combustion chamber. Furthermore, efficiency becomes an equivalent paradigm as performance. In the power unit layout, the air path is defined by the compressor, the intercooler and the piping from the intake plenum to the cylinder. Intake duct length is defined from intake plenum to valve seat and it is a key parameter for engine performance.
The paper aims at defining a methodology for the prediction and understanding of knock tendency in internal combustion engine piston crevices by means of CFD simulations. The motivation for the analysis comes from a real design requirement which appeared during the development of a new high performance SI unit: it is in fact widely known that, in high performance engines (especially the turbocharged ones), the high values of pressure and temperature inside the combustion chamber during the engine cycle may cause knocking phenomena. “Standard” knock can be easily recognized by direct observation of the in-cylinder measured pressure trace; it is then possible to undertake proper actions and implement design and control improvements to prevent it with relatively standard 3D-CFD analyses.
Engine valve flow coefficients are used to describe the flow throughput performance of engine valve/port designs, and to model gas exchange in 0D/1D engine simulation. Valve flow coefficients are normally estimated at a stationary flow test bench, separately for intake and exhaust side, in the absence of the piston. However, engine operation differs from this setup; i. a. the piston might interact with valve flow around scavenging top dead center, and instead of steady boundary conditions, valve flow is nearly always subjected to pressure pulsations, due to pressure wave reflections within the gas exchange ports. In this work the influences of piston position and pressure pulsation on valve flow coefficients are investigated for different SI engine geometries by means of 3D CFD and measurements at an enhanced flow test bench.
Natural gas is a promising alternative gaseous fuel due to its availability, economic, and environmental benefits. A solution to increase its use in the heavy-duty transportation sector is to convert existing heavy-duty compression ignition engines to spark-ignition operation by replacing the fuel injector with a spark plug and injecting the natural gas inside the intake manifold. The use of numerical simulations to design and optimize the natural gas combustion in such retrofitted engines can benefit both engine efficiency and emission. However, experimental data of natural gas combustion inside a bowl-in-piston chamber is limited. Consequently, the goal of this study was to provide high-quality experimental data from such a converted engine fueled with methane and operated at steady-state conditions, exploring variations in spark timing, engine speed and equivalence ratio.
The more stringent regulations on emissions induce the automotive companies to develop new solutions for engine design, including the use of advanced combustion strategies and the employment of mixture of fuels with different thermochemical properties. The HCCI combustion coupled with the partial direct injection of the charge, in order to control the performance and emissions and to extend the operating range, is a promising technique. In this work an in-house developed multi-dimensional CFD software package was used to analyse the behaviour of a multi stage direct injection (DI)-partially stratified charge compression ignition engine fueled with PRF. A skeletal kinetic mechanism for PRF oxidation was employed, with a dynamic adaptive chemistry technique to reduce the computational cost and a model based on the partially stirred reactor model to couple turbulence and chemistry.
Low temperature combustion (LTC) strategies have been a keen interest in the automotive industry for over four decades since they offer improved fuel efficiency compared to conventional spark-ignition (SI) engines. LTC strategies use high dilution to keep combustion temperatures below about 2000 K to reduce heat transfer losses while avoiding locally rich in-cylinder regions that produce high soot. High dilution also enables an efficiency improvement from reduced pumping work and improved thermodynamic properties, though it requires high ignition energy. Combustion can be achieved by triggering autoignition from compression energy. High compression ratios are typically required to produce this level of ignition energy, which further improves fuel efficiency. The timing of the autoignition event is influenced by fuel properties and mixture composition, and is exponentially sensitive to temperature.