Examinatal Study on Common Rail Diesel Engine for Multi-injection Strategies
Based on diesel engine equipped with common rail, the multi-injection strategies common rail diesel engine test bed is established with NI test system. In this test bed, the influences of optimized multi-injection strategies to diesel engine performances are studied. The test results show that by using multi-injection strategies, the diesel engine exhaust temperature can reduce 50???, and noises can reduce 15dB, and emission improve obviously.
A comparative assessment on Common Rail Direct Injection (CRDI) engine characteristics using low viscous biofuel blends
Abstract The current study compares the performance, emission and combustion characteristics of two different biofuel extracted from waste peels of lemon and orange fruit through steam distillation process in common rail direct injection engine. The study is further extended by variation of parameters such as injection pressures, split injection quantities and exhaust gas recirculation. The brake thermal efficiency for orange peel is higher than diesel and lemon peel oil at 600 bar with 10% of pilot fuel quantity. The similar cetane index of orange peel oil (OPO) means there is minimal performance drop for its blend and lemon peel oil (LPO) performs well as compared to diesel however this benefit is not greater than OPO. However, for 30% pilot fuel quantity the fuel efficiency is dropped by 10.74% and 4.72% for OPO and LPO respectively as compared to 10% pilot fuel quantity. Through the use of a greater quantity of pilot fuel injection, the low viscosity of LPO further increases its performance characteristics whereas OPO sees a decrement. The inherent oxygen content of both biofuel blends shows reduced emission of un-burnt hydrocarbon and carbon monoxide emissions under 600 bar and 10% pilot injection with the penalty of oxides of nitrogen emission.
Computer-Aided System of Virtual Testing of Gas Turbine Engines
The article describes the concept of a virtual lab that includes subsystem of gas turbine engine simulation, subsystem of experiment planning, subsystem of measurement errors simulation, subsystem of simulator identification and others. The basis for virtual lab development is the computer-aided system of thermogasdynamic research and analysis “ASTRA”. The features of gas turbine engine transient modes simulator are described. The principal difference between the simulators of transient and stationary modes of gas turbine engines is that the energy balance of the compressor and turbine becomes not applicable. The computer-aided system of virtual gas turbine engine testing was created using the developed transient modes simulator. This system solves the tasks of operational (throttling, speed, climatic, altitude) characteristics calculation, analysis of transient dynamics and selection of optimal control laws. Besides, the system of virtual gas turbine engine testing is a clear demonstration of gas turbine engine working process and the regularities of engine elements collaboration. The interface of the system of virtual gas turbine engine testing is described in the article and some screenshots of the interface elements are provided. The developed system of virtual gas turbine engine testing provides means for reducing the laboriousness of gas turbine engines testing. Besides, the implementation of this system in the learning process allows the diversification of lab works and therefore improve the quality of training.