scholarly journals Investigation of Optimization of Combustion Processes in the Engine of Combat Vehicles by Use of Disk Structure

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7039
Author(s):  
Igor Korobiichuk ◽  
Viktorij Mel’nick ◽  
Volodimir Karachun ◽  
Vladyslav Shybetskyi

This work analyzes the possibility of a provision of force-majeure mode of the combat vehicles with the aid of disk construction installed in the baffler, the base of the operation of which is the method of residual cyclical quadratic chain code of construction of the “windows” of the movable disk. To determine the optimal parameters of the moving disk of the rotor system, mathematical modeling was performed. The results of mathematical modeling were used to create a PC-based calculation program. The calculation was performed for the rotational frequency ω = 300 s−1 andfor harmonic numbers from 1 to 100. The waveforms used in simulation were as follows: quasi-trapezoidal and rectangular. It is established that at the number of “windows” m = 276 in the moving disk of the rotor system the radiation spectrum acquires a uniform distribution. The object of the research is the process of extreme burning of fuel material in the combat vehicles’ engines, ensuring, according to the technical possibilities of the engine, the implementation of the force-majeure mode of the combat vehicle in the whole. The quantitative and qualitative criteria of fullness of fuel material burning in the engine are chosen as the basis for the evaluation of the reaching of the force-majeure mode. The “flat noise” of the efflux is chosen as the basis of this evaluation. This method ensures the construction of the stochastic structure of “flat noise” in the engine efflux and, in that way, confirms the possibility of technical implementation of the force-majeure mode. The rotor system further ensures not only the force-majeure formation, but also reaches the minimum noise of the combat vehicle at the change of its dislocation. The research results can be further used to optimize the design of exhaust systems, which will reduce emissions.

Author(s):  
Chen Zhang ◽  
Zongxuan Sun

A novel combustion control, i.e. the trajectory-based combustion control, was proposed previously. This control is enabled by free piston engines (FPEs) and utilizes the FPE’s controllable piston trajectory to enhance thermal efficiency, reduce emissions and realize variable fuels applications. On top of that, a control-oriented model was also developed aimed to implement the trajectory-based combustion control in real-time. Specifically, a unique phase separation method was proposed in the model, which separates an engine cycle into four phases (pure compression, ignition, heat release and pure expansion) and employs the minimal reaction mechanism accordingly. In this paper, the framework of the previous control-oriented model is extended to variable fuels, such as methane, n-heptane and bio-diesel. Such an extension is reasonable since the separated four phases are representative in typical combustion processes of all fuels within an engine cycle. Besides, a least-squares optimization is formulated to calibrate the chemical kinetics variables for each fuel. At last, simulation results and the related analysis show that all the derived control-oriented models have high fidelity and much lighter computational burdens to represent the HCCI combustion of each fuel along variable piston trajectories.


2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Yahui Cui ◽  
Zhansheng Liu ◽  
Yongliang Wang ◽  
Jianhuai Ye

To investigate the effect of oil film force on a geared rotor system, a short journal bearing model was applied to represent nonlinear oil film force. A dynamic model of the geared rotor oil journal bearing system was presented. The nonlinear gear mesh force and nonlinear oil film force were considered in the model. The nonlinear dynamic responses of the system were investigated by numerical integration method. This article shows that when the rotational speed is relatively low, the vibration of the system is mainly affected by nonlinear mesh force. With the increase of rotational speed, the influence of nonlinear oil film force also increases gradually, and the subsynchronous forward precession phenomena appear. When the speed increases to a certain value, the amplitude of the subsynchronous forward precession exceeds the amplitude of the rotational frequency, and the nonlinear mesh force is greatly affected by the nonlinear oil film force. However, the linear oil film force does not affect the nonlinear mesh force. The subsynchronous forward precession is difficult to be predicted by linear oil film force which was previously applied. This experiment is performed to validate the correctness of the dynamic model presented, and the numerical integration results of low speeds are validated by the experimental data.


2001 ◽  
Vol 1 ◽  
pp. 879-896 ◽  
Author(s):  
Jan Willem Erisman ◽  
Peringe Grennfelt ◽  
Mark Sutton

Europe has been successful in reducing the emissions of several nitrogenous pollutants over recent decades. This is reflected in concentrations and deposition rates that have decreased for several components. Emissions of nitrogen containing gases are estimated to have decreased in Europe by 10%, 21%, and 14% for NO, NOx, and NH3, respectively, between 1990 and 1998. The main reductions are the result of a decrease in industrial and agricultural activities in the east of Europe as a result of the economic situation, measures in the transport sector, industry and agricultural sector, with only a small part of the reduction due to specific measures designed to reduce emissions. The reduction is significant, but far from the end goal for large areas in Europe in relation to different environmental problems. The Gothenburg Protocol will lead to reductions of 50 and 12% in 2010 relative to 1990 for NOx and NH3, respectively. The N2O emissions are expected to grow between 1998 and 2010 by 9%. Further reductions are necessary to reach critical limits for ecosystem protection, air quality standards and climate change. Emissions of nitrogen compounds result from an overload of reactive nitrogen, which is produced by combustion processes, by synthesis of ammonia or by import from other areas as concentrated animal feeds. Although some improvements can be made by improving the efficiency of combustion processes and agricultural systems, measures to reduce emissions substantially need to be focused on decreasing the production or import of reactive N. Reactive N ceilings for regions based on critical limits for all N-related effects can help to focus such measures. An integrated approach might have advantages over the pollutant specific approach to combat nitrogen pollution. This could provide the future direction for European policy to reduce the impacts of excess nitrogen.


2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Fabian Feldhaus ◽  
Ingo Schmitz ◽  
Thomas Seeger

AbstractEmissions of internal combustion engines are linked to air pollution, global warming effects and are potentially harmful. In order to reduce emissions, a better understanding of combustion processes is necessary. Therefore, the combustion temperature is an important factor to know, because it has an impact on the amount of exhaust gases like soot and nitrogen oxides. This work presents a complete spectral resolved emission spectroscopy based sensor system for temperature determining in compression ignition engines. The sensor system is developed for series engines and can be used without any modification of the engine.


Author(s):  
Choluk Ri ◽  
Chunghyok Chae ◽  
Kwanggyun Sin ◽  
Yongil Sin ◽  
Kwangil Ri ◽  
...  

In this paper, based on the theory of rotor dynamics, the nonlinear dynamics of a rotor system with an eccentric rotor is analyzed. Taking the double-support rotor system with a single turntable as the object, the mathematical modeling method of the rotor system with an eccentric rotor and the rotation analysis of the turntable are analyzed in detail. According to ANSYS software, the influence of eccentricity on the rotor system and the relationship between eccentricity and nonlinearity are analyzed.


2021 ◽  
Author(s):  
E. V. Radkevich ◽  
N. N. Yakovlev ◽  
O. A. Vasil’eva

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