Optimal Control of the Heat Release Rate of an Internal Combustion Engine With Pressure Gradient, Maximum Pressure, and Knock Constraints

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Florian Zurbriggen ◽  
Tobias Ott ◽  
Christopher Onder ◽  
Lino Guzzella
Keyword(s):  
Optimal Control ◽  
Pressure Gradient ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Mechanical Work ◽  
Maximum Pressure ◽  
Temperature Dependent ◽  
Ideal Gases ◽  
Burn Rate

In this paper, we present an analysis of the optimal burn rate in an internal combustion engine (ICE) considering pressure gradient, maximum pressure, and knocking. A zero-dimensional model with heat losses is used for that purpose. The working fluids are assumed to behave like ideal gases with temperature dependent gas properties. In the first part, it is assumed that the burn rate can be arbitrarily chosen at every time instance in order to maximize the mechanical work. This leads to an optimal control problem with constraints. In the second part, a Vibe type burn rate is assumed, where the center of combustion, the duration and the form factor can be chosen in order to maximize the mechanical work. This Vibe type burn rate is finally compared with the arbitrary combustion as the benchmark in order to evaluate the potential of the more realistic burn shape.

Effects of Compression Ratio on Performance and Emission of Internal Combustion Engine with Used Vegetable Oil Methyl Easter

2013 ◽  
Vol 768 ◽  
pp. 250-254
Author(s):  
N. Balakrishnan ◽  
K. Mayilsamy ◽  
N. Nedunchezhian
Keyword(s):  
Internal Combustion Engine ◽  
Vegetable Oil ◽  
Compression Ratio ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Maximum Pressure ◽  
Base Line ◽  
Promising Alternative ◽  
Performance And Emission ◽  
Used Vegetable Oil

Biomass derived vegetable oil is a promising alternative fuel for an internal combustion engine. Direct use of vegetable oil has inferior performance with higher emission due to its higher viscous in nature. This can be overcome by transesterification process with its byproduct which is called as used vegetable oil methyl ester. While blending this biodiesel with fossil diesel upto maximum of 30:70, will give the higher performance and lower emission than the fossil diesel alone. In this present study biodiesel in the form of B23 is used in a four stroke water cooled variable compression ratio engine without any modifications. The performance and emission characteristics are studied with different compression ratio and compared with a base line fossil diesel mode operation. This study reveals that the compression ratio of 18 is the optimum in the view of ignition delay, maximum pressure crank angle, exhaust gas temperature and Smoke emission.

scholarly journals TECS - a Dedicated Software for Thermal Engine Calculation

2018 ◽  
Vol XIX (1) ◽  
pp. 424-429
Author(s):  
Cebanu Andrei
Keyword(s):  
Internal Combustion Engine ◽  
Thermal Energy ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Mechanical Work ◽  
Dynamic Processes ◽  
Starting Point ◽  
Software Program

This paper addresses the thermal engine calculation problematics using a dedicated software program (TECS) in order to determine the indicated and effective engine parameters using different fuels (liquid or gaseous). The diagram indicated thus obtained by TECS can contribute to verify the judicious use of thermal energy, obtained through combustion of fuel and its transformation into Mechanical Work. The analysed thermo-dynamic processes can analytically and graphically determine the polytrophic exponents of compression and decomposition in values close to the stoichiometric calculations. The TECS software is addressed to the current and future electro-mechanical naval engineers with concrete concerns in verification, analysis and calculation of thermo-dynamic processes that govern the operation of the ship internal combustion engine. It can be a starting point eloquently in appreciation of fair uses thermal energy on board.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

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