scholarly journals Development of a method for selecting a cruising mode and engine control program of a ramjet aircraft

2021 ◽  
Vol 3 (3 (111)) ◽  
pp. 6-14
Author(s):  
Oleh Kislov ◽  
Mykhailo Shevchenko
Keyword(s):  
Fuel Consumption ◽  
Power Plants ◽  
Control Program ◽  
Operating Mode ◽  
Specific Fuel Consumption ◽  
Engine Control ◽  
Engine Operation ◽  
Control Factors ◽  
Range Parameter ◽  
Operation Parameters

For supersonic cruising, combined power plants can be used, in which a gas turbine engine reaches the cruising mode, and a ramjet is used for cruising. Supersonic transoceanic flights are characterized by a long cruising segment, which is decisive in terms of required fuel mass. Therefore, the selection of cruising and engine operation parameters is an important task. As a rule, when selecting the cruising mode, the range parameter is used, which depends on the flight and engine operation modes. To take into account the influence of the ramjet operating mode on the range parameter, dimensionless relationships of engine parameters with control factors were obtained. Using the obtained relationships together with the equations of aircraft motion in steady horizontal flight, it is shown that the values of the engine control factors and the range parameter do not change at the altitudes of 11...20 km. This made it possible to conclude that the range parameter can be increased only by selecting the cruising and engine parameters that provide the minimum specific fuel consumption. The variable cruising parameters are speed and initial altitude. A method for selecting the cruising and ramjet operation parameters was developed, based on the analysis of the relationship between the range parameter and the flight speed and initial altitude at the most advantageous values of the engine control factors. The obtained relationships allow selecting the cruising parameters and the engine operating mode, taking into account the restrictions. It is shown that the specific fuel consumption decreases by 0...30 %, depending on the engine operating mode, when the control program is optimized

scholarly journals STATE AND PROSPECTS OF THERMAL POWER GENERATION IN THE CONDITIONS OF UKRAINE’S COURSE ON CARBON-FREE ENERGY

2021 ◽  
pp. 4-16
Author(s):  
M.V. Cherniavskyi
Keyword(s):  
Power Generation ◽  
Free Energy ◽  
Power System ◽  
Fuel Consumption ◽  
Power Plants ◽  
Thermal Power ◽  
Specific Fuel Consumption ◽  
Regulatory Function ◽  
Thermal Power Plants ◽  
Thermal Power Generation

The structure of electricity cost formation for consumers, including depending on the cost of TPP generation, «green» energy and other sources, is investigated, and the main conditions of the efficient regulatory function fulfillment in the power system by thermal power generation in the conditions of Ukraine's course on carbon-free energy are formulated. It is shown that excessive electricity losses in networks and, especially, accelerated increase of the share of «green» generation, much more expensive than nuclear, hydro and thermal, mainly contribute to the growth of electricity costs for non-household consumers and the need to raise tariffs for the population. This accelerated increase directly contradicts the Paris Climate Agreement, according to which plans to reduce Ukraine’s greenhouse gas emissions must be developed taking into account available energy resources and without harming its own economy. The dependences of the specific fuel consumption on the average load and the frequency of start-stops of units are found and it is shown that the increased specific fuel consumption on coal TPPs is an inevitable payment for their use as regulating capacities of UES of Ukraine. In this case, the higher the proportion of «green» generation and a smaller proportion of generating thermal power plants, especially increasing specific fuel consumption. It is proved that in the conditions of growth of the share of «green» generation in Ukraine the share of production of pulverized coal thermal power plants should be kept at the level of not less than 30 % of the total electricity generation. It is substantiated that a necessary condition for coal generation to perform a proper regulatory role in the power system is to introduce both environmental and technical measures, namely — reducing the suction of cold air to the furnace and other boiler elements, restoring condensers and cooling systems, etc. An important factor in reducing the average level of specific fuel consumption is also the reduction of coal burn-out at thermal power plants, where it still remains significant, due to the transfer of power units to the combustion of bituminous coal concentrate. Bibl. 12, Fig. 5, Tab. 5.

scholarly journals ОСОБЕННОСТИ РАСЧЕТА И РЕГУЛИРОВАНИЯ ДВУХКОНТУРНОГО ТУРБОРЕАКТИВНОГО ДВИГАТЕЛЯ С ФОРСАЖНОЙ КАМЕРОЙ СГОРАНИЯ В НАРУЖНОМ КОНТУРЕ НА ПРЯМОТОЧНЫХ РЕЖИМАХ РАБОТЫ

2020 ◽  
pp. 15-23
Author(s):  
Олег Владимирович Кислов ◽  
Михаил Анатольевич Шевченко
Keyword(s):  
Mathematical Model ◽  
Fuel Consumption ◽  
Control Program ◽  
Critical Section ◽  
Specific Fuel Consumption ◽  
Outlet Section ◽  
Nozzle Outlet ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Ramjet Engines

A promising direction in aviation is the creation of anaircraft for supersonic cruise speeds (Mach 3...4). It is known that ramjet engines are more preferable for Mach numbers larger 3. However, they do not have starting thrust and uneconomical at subsonic flight speeds. At the same time, at subsonic flight speeds, turbofan engines are the most expedient. The combination of the positive properties of turbofan engines at subsonic speeds and a ramjet engines at supersonic speeds is possible by using duct-burning turbofan engine, which can operate at the ramjet mode with the blocked gas turbine duct at supersonic flight conditions. At this mode, duct-burning turbofan engine turns into ramjet engine, which, however, has special features due to the presence of fan in front of the combustion chamber, which operates in turbine mode or in zero power mode and also because of the outlet jet, which has annular shape, flows out from the duct causes the appearance of bottom drag. The presence of bottom drag requires both the development of a mathematical model for its calculation and taking into account its influence on the choice of the control law for the nozzle outlet area. The article presents a mathematical model of the working process of duct-burning turbofan engine at ramjet mode, taking into account the presence of fan in the flow path and bottom drug. Using the developed mathematical model, the regularities of changes in the internal and effective thrust, as well as the specific fuel consumption, depending on the relative fuel consumption and the critical section of the nozzle at a given altitude and flight speed are established. The critical section of the nozzle is the main regulating factor, and the relative fuel consumption is related to the main regulating factor - the fuel consumption. These patterns are useful for choosing a control program.There is such a combination of regulating factors whichprovides two extremes in the regularities of trust and specific fuel consumption changes: the mode of minimum specific fuel consumption and the mode of maximum thrust. In addition, the influence of gas underexpansion in the nozzle on the thrust-economic parameters of the engine and the required area of the nozzle outlet section were estimated. The obtained regularities are advisable to use when engine control program is chosen.

scholarly journals Average Fuel Consumption by a Ship on a Sales Line in Statistical Weather Conditions

2018 ◽  
Vol 1 (1) ◽  
pp. 573-579
Author(s):  
Tadeusz Szelangiewicz ◽  
Katarzyna Żelazny
Keyword(s):  
Fuel Consumption ◽  
Weather Conditions ◽  
Engine Control ◽  
Weather Parameters ◽  
Operation Parameters ◽  
Control Criteria ◽  
Ship Operation ◽  
Seasonal Weather

Abstract During operation of the ship, fuel consumption and associated emissions are very important for economic and ecological reasons. The fuel consumption is greatly influenced by the choice of shipping route, weather conditions on these routes and engine control criteria. The article presents its own algorithm for forecasting ship operation parameters, including fuel consumption on selected shipping routes for average, statistical (seasonal) weather parameters occurring on these routes. It shows what factors have the main impact on fuel consumption and how you can affect fuel consumption during the cruise in changing weather conditions.

scholarly journals Efficiency of using inverter power plants as part of multifunctional energy technology complexes

2020 ◽  
Vol 21 (4) ◽  
pp. 244-253
Author(s):  
Ivan Ya. Redko ◽  
Andrey A. Malozemov ◽  
Georgiy A. Malozemov ◽  
Alexey V. Naumov ◽  
Dmitry V. Kozminykh
Keyword(s):  
Power Plant ◽  
Fuel Consumption ◽  
Damage Accumulation ◽  
Power Plants ◽  
Fuel Efficiency ◽  
Point Of View ◽  
Operating Conditions ◽  
Simultaneous Increase ◽  
Boost Pressure ◽  
Engine Operation

A method has been developed for a comprehensive multi-criteria assessment of the efficiency of using inverter power plants as part of multifunctional energy-technological complexes with technical solutions aimed at reducing the negative consequences of the internal combustion engine operation with an optimal from the point of view of fuel efficiency speed. The method includes: synthesis of the optimal engine speed control algorithm, determination of the complex operating modes under operating conditions, assessment of changes in fuel consumption and harmful substances emissions with exhaust gases and resource consumption rate when the engine is switched to the operating mode with the optimal speed, complex technical and economic assessment of the inverter power plants efficiency. On the example of an inverter power plant with a capacity of 100 kW, the need to apply the method is proved. It was found that the engine operation with the optimal from the point of view of fuel efficiency speed and without additional design measures entails an increase in the damage accumulation rate by 1.7-2.1 times and therefore is economically inexpedient, despite a decrease in fuel consumption by 1% or more. It was found that a decrease in the compression ratio with a simultaneous increase in the boost pressure makes it possible to increase the engine resource up to a functional failure due to damage accumulation by 43% and to a parametric failure due to wear by 32%, while the operating costs of the inverter power plant will decrease by 3.7% relative to the base (no changes) power plants. The emission of soot particles will decrease by about 2 times, nitrogen oxides - by 2%, hydrocarbons - almost to zero.

Effect of Turbocharger Cut Out on Two-Stroke Marine Diesel Engine Performance and NOx Emissions at Part Load Operation

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Nikolaos F. Sakellaridis ◽  
Efthimios Pariotis ◽  
Antonis K. Antonopoulos ◽  
Leonidas Zissimatos ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Negative Impact ◽  
Specific Fuel Consumption ◽  
Engine Operation ◽  
Slow Steaming ◽  
Low Load ◽  
Marine Diesel ◽  
Promising Solution

The diesel engine is widely used for marine vessel propulsion due to its relatively high efficiency compared to existing alternative propulsion systems. The majority of these engines are slow speed two stroke ones. Despite the improvement of their efficiency there now exists a demand for drastic reduction of daily fuel oil consumption as a result of the global financial situation and continuously increasing fuel prices. Towards this effort, slow steaming is a promising solution for the drastic reduction of daily and specific fuel consumption when expressed in tn/mile. This requires engine operation in the low load (low speed) range where these engines are not designed to operate for long term. The main problem related to slow-steaming, is the lack of air which has a negative impact on the engine and its subsystems. A promising solution to the problem is turbocharger (T/C) cut-out at low load when more than one T/C exists. In the present work a combined computational and experimental investigation is conducted to evaluate the operation potential of a large two stroke marine diesel engine equipped with two T/Cs using T/C cut-out, for which the specific technology presents various challenges. This is achieved using an in-house engine simulation model and measurements with and without T/C cut-out. From the results it is revealed that using this technique the scavenging air and peak firing pressure increase while the specific fuel consumption decreases. In this way, some major problems related with the long term operation of the engine under low load conditions, i.e. accumulation of carbon deposits on the exhaust gas side and continuous operation of the auxiliary air blowers, are surpassed. Moreover, a theoretical investigation is conducted considering fuel injection retard to minimize the peak firing pressure penalty while taking care to limit the corresponding negative impact on specific fuel consumption. For NOx emissions the effect of T/C cut-out is also considered using tail pipe emission data measured during the official shop tests. From the analysis conducted it has been revealed that the technique of turbocharger cut–out (one of two) is technically feasible and could offer certain advantages when slow-steaming is implemented. Moreover, comparing the calculated with the measured results, it has been revealed that the simulation model successfully estimates engine operation with and without T/C cut-out, being a valuable tool for the engineers to investigate combustion and pollutant formation mechanisms under various engine configurations.

scholarly journals Experimental Study of the Effect of Fuel Catalytic Additive on Specific Fuel Consumption and Exhaust Emissions in Diesel Engine

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 54
Author(s):  
Marcin Tkaczyk ◽  
Zbigniew J. Sroka ◽  
Konrad Krakowian ◽  
Radoslaw Wlostowski
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Thermal Efficiency ◽  
Combustion Process ◽  
Specific Fuel Consumption ◽  
Fuel Additive ◽  
Engine Operation ◽  
Catalytic Additives ◽  
Positive Effect ◽  
Catalytic Additive

Fuel catalytic additives have been tested for many years. Herein, their influence on the overall efficiency of combustion engines is investigated, and their pro-ecological impact is assessed. The majority of this research concerns diesel engines. Despite many advantages, to this day, the use of catalytic additives has not become widespread. Wishing to clarify the situation, a research group from the Wroclaw University of Science and Technology decided to investigate this matter, starting with verification tests. This article presents the methodology and results of testing an actual diesel engine, and evaluates the effects of the use of a fuel catalytic additive. The focus was on the analysis of fuel consumption and exhaust gas emissions from a Doosan MD196TI engine. The tested additive was a commercial fuel performance catalyst (FAMAX) with up to 5% ferric chloride as an organometallic compound. The proportion of the mixture with the fuel was 1:2000. These studies provide an energy and ecological assessment of propulsion in inland vehicles relative to current exhaust emission standards. The tests were carried out in accordance with the ISO 8178 standard, albeit on a much broader scale regarding engine operation than required by the standard. In this way, a set of previously published data was more than doubled in scope. Detailed conclusions indicate the positive effect of the tested fuel additive. The emission values decreased, on average by 16.7% for particulate matter (PM), 10.1% for carbon monoxide (CO), and 7.9% for total hydrocarbons (THC). Unfortunately, the amount of nitrogen oxides (NOx) increased by 1.2%. The average difference in specific fuel consumption (BSFC) between the fuel with additive and pure diesel fuel was 0.5%, i.e. below the level of measurement error. The authors formulated the following scientific relationship between the thermal efficiency of the engine and the operation of the catalyst: the effect of the catalyst on the combustion process decreases with the increase of the thermodynamic efficiency of the engine. This conclusion indicates that despite the proven positive effect of catalysts on the combustion process, they can only be used in markets where engines with low thermal efficiency are used, i.e., older generation engines.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

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