Authors: Udit Kaul, Mahendarpal and Madhusudan Joshi Organization: International Centre for Automotive Technology, Manesar Introduction: In this paper, a study concerning multi-point CNG injectors (MPCI) or commonly known as injector rail would be presented. Here we would make a detailed analysis regarding the performance of MPCIs due to variation in physical and electrical parameters. In this case multiple MPCIs would be considered and there electrical and dimension parameters would be compared with respect to their performance. The performance comparison would be done based on the common compliance standard under standard laboratory conditions. We would also like to propose the optimal combination of electrical and dimension parameters for better performance. The variables to be considered for the proposed study are: injector valve open/shut timing, injector dimension, voltage levels, solenoid types etc. Key words : multi-point CNG injectors, injector valve, solenoid

In order to reduce engine development timing and cost, a numerical calculation used to evaluate valve train systems. This paper discusses the work done on kinematic and dynamic analysis of Valve Train (VT) system of a diesel engine by using 1-D Ricardo Valdyn software. The goal is to meet optimum intake, exhaust valve timing requirement, maximize valve open area and 20% overspeed requirement. Valve train model is prepared and inputs like mass and stiffness are estimated from actual weighing and finite element approach respectively. Simulation model is used for predicting valve bounce speed, valve displacement, cam-follower contact stress and strain in the rocker arm. Initially, Kinematic analysis is carried out to study the change in valve motion characteristics such as cam contour radius, tappet contact eccentricity etc. Further to this, dynamic analysis is carried out to assess forces and stresses on valve train components. Effect of cam tappet contact stresses, buckling load on push rod, spring surge, ratio of spring force to inertia force, valve seating velocity at increased speed condition etc. are discussed in…

This paper describes the design of a novel pneumatic gear shifting system to replace the existing gear stick manual shifting system for ease of the driver while shifting gears. The aim of this work is to have a semi-automatic shifting (pneumatic shifting) removing the need for the driver clutch operation. The system consists of a solenoid valve, CO2 gas-pressurized cylinder, double-acting cylinder, and single-acting cylinder. On basis of the signal received the gear needs to be changed, the shifter opens or closes a magnetic valve assembly. The solenoid valve allows the compressed air into the piston that comes from a pressurized cylinder, in order to create the effect of shifting gears. The pedal shifter and buttons are used to shift the gears. The pedal shifter was designed by using a 3-D printing technique using PLA material. The microcontroller used is ATMEGA-328 in this system. There are three switches, one for upshift, downshift, and clutch respectively. An algorithm has been created in a microcontroller for a sequential gearbox of CBR 600RR. The system has been so…

The restrictor is a component which controls the mass flow of air passing to the engine. The proposed work focuses on design and analysis of air intake restrictor of Duke 390cc engine which is used in formula vehicles. As an constrain of this system, the air flows through a single circular throat of diameter 20mm. In past decades conventional venture nozzles were used as a restrictor but it leads to nominal press drop. A de lavel nozzle is a tube pinched in the middle, making an asymmetric hourglass shape. It is used to accelerate a higher supersonic speed in the axial direction. The main objective is to utilize De-Laval Nozzle for the minimal pressure drop. The change in pressure will increases the engine power output. The analysis is done by varying design conditions such as three levels of convergent (12,14 and 16 degrees) and three levels of divergent angles (4, 6 and 8 degrees) are taken into consideration. After numerous CFD Simulations, it is inferred that the optimal angles of 14 and 4 degrees for…

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 determined 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 flow 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. In the past, most research work on valve flow coefficients left aside possible piston influence and, for dynamic boundary conditions, it largely omitted subtraction of the gas inertia effects, which are already covered by 1D simulation. In this work, concerning piston influence, various valve overlap…

The 2014 change in Formula One regulations, 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 a 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. In order to find the optimum length different design criteria can be applied: the so called “tuning”, the “un-tuning” or the “anti-tuning” are all valid possibilities, showing pros and cons. The scope of the paper is to study and present the possible different tuning options for the internal combustion engine (ICE) part…

This paper investigates the effects of hybrid electric turbocharging on the total system efficiency, the transient loading capability and the operational range of maritime engines, including the effects of the air control valves (cylinder bypass & charge air blow-off valve). An existing and validated mean-value first principle engine model has been adapted to simulate the operating principle of a combustion engine with a hybrid electric turbocharger system. The simulation of power-take-off/in together with an excess air ratio control strategy is included by means of torque addition to/removal from the turbocharger shaft and limiting it with seven boundary controllers. The analysis of the simulation results illustrates a trade-off between the increase of the system efficiency on one side and the transient loading capability of the engine on the other side. With turbocompounding, the system efficiency can be increased at the expense of a deteriorated gas exchange process and increased thermal loading of the engine. And assisting the turbocharger for steady state operation leads to a smaller operating envelope due to the limitation of compressor surge. Combining…