An Optimal Control Approach to Minimizing Entropy Generation in an Adiabatic Internal Combustion Engine

2006 ◽  
Author(s):  
Kwee-Yan Teh ◽  
Christopher F. Edwards
Keyword(s):  
Optimal Control ◽  
Internal Combustion Engine ◽  
Entropy Generation ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Control Approach ◽  
Optimal Control Approach

scholarly journals Entropy Generation Optimization in Internal Combustion Engine

2015 ◽  
Vol 2 (S1) ◽  
pp. 233-242 ◽  
Author(s):  
F. Bouras ◽  
M. E. H. Attia ◽  
F. Khaldi
Keyword(s):  
Internal Combustion Engine ◽  
Entropy Generation ◽  
Combustion Engine ◽  
Internal Combustion

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.

An Optimal Control Approach to Minimizing Entropy Generation in an Adiabatic IC Engine With Fixed Compression Ratio

2006 ◽  
Author(s):  
Kwee-Yan Teh ◽  
Christopher F. Edwards
Keyword(s):  
Optimal Control ◽  
Entropy Generation ◽  
Compression Ratio ◽  
Combustion Engine ◽  
Optimal Solution ◽  
Combustion Mechanism ◽  
Control Input ◽  
Piston Velocity ◽  
Ic Engine ◽  
Control Approach

Entropy generation due to combustion destroys as much as a third of the theoretical maximum work that could have been extracted from the fuel supplied to an engine. In this paper, an optimal control problem is set up to minimize the entropy generation in an adiabatic internal combustion engine, with the piston velocity profile serving as the control input function. The compression ratio of the engine is fixed, thereby imposing a constraint on the piston motion. The switching conditions for the optimal bang-off-bang control is determined based on Pontryagin's maximum principle. In thermodynamic terms, the optimal solution reduces to a strategy of equilibrium entropy minimization. This result is independent of the underlying combustion mechanism.

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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