scholarly journals Experimental studies of internal combustion engine in cracking-gas operation

Author(s):  
M.I. Arpabekov ◽  
◽  
A.A. Baubek ◽  
T.B. Suleimenov ◽  
Zh.M. Kuanyshbayev ◽  
...  
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко

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.


2011 ◽  
Vol 159 (1) ◽  
pp. 155-167
Author(s):  
Włodzimierz KUPICZ ◽  
Stanisław NIZIŃSKI

The paper presents a new method for diagnosing an internal combustion engine with compression ignition under traction conditions. The gist lies in determining the engine torque on the basis of acceleration recording in traffic conditions. The results of extensive preliminary and basic experimental studies have been discussed. Three options have been developed of the internal combustion engine diagnostic model, using the trivalent assessment of states. State control and engine damage localization algorithms have been proposed. The new method has been examined under traction conditions. The probability of the internal combustion engine correct diagnosis ranges between 0.85÷1.


2021 ◽  
Vol 20 (3) ◽  
pp. 97-109
Author(s):  
V. V. Biryuk ◽  
A. A. Gorshkalev ◽  
M. O. Zakharov ◽  
V. L. Larin

On the basis of the available theoretical calculations, methods for calculating the working process and power characteristics of internal combustion engines and the experimental studies carried out, a method for calculating the working process for small-sized two-stroke internal combustion engines was developed and tested. In the course of this work, the following results were obtained: the parameters of the working process and power characteristics of a small two-stroke internal combustion engine; the parameters obtained by calculation during the study of the Evolution 20GX2 engine were compared with the results of an experimental study. According to the results of the comparison, deviations in the values of the parameters of the engine under study from the results of the experimental study at the maximum power and maximum speed modes were identified.


2019 ◽  
pp. 15-19
Author(s):  
Виктория Сергеевна Корниенко ◽  
Роман Николаевич Радченко

Obtaining additional energy due to the deep utilization of the internal combustion engine (ICE) heat losses al-lows saving fuel used for the operation of the ship's power plant. This accordingly leads to a reduction of the emissions of harmful substances into the atmosphere, contributes to meet the more stringent standards of the International Maritime Organization (IMO) governing the limits of these emissions. The study aims to develop the system of complex exhaust gas cleaning for an internal combustion engine (ICE). For solving the tasks in the technology of proposed method there were 6 stages of technological process envisaged. Based on experimental and theoretical studies, a setup for complex exhaust gas cleaning using a cyclone and the effect of "microexplosions" of a water-fuel emulsion (WFE) droplet was developed. It has been established that as a result of activated WFE combustion we obtain at the engine outlet exhaust gases of a corresponding composition with a reduced amount of toxic ingredients down to 35 % and below and most importantly – an equimolar ratio of NO2 /NO to NOx. Experimental studies have shown that in the condensate acid under these conditions, an average concentration of about 57 % is established, which ensures a sharp increase in the absorption of SO2 and NOx. The presence of an equimolar (or almost this) NO2 /NO ratio in gases ensures the passivation of the condensation surface in exhaust gas boiler (EGB) from carbon steel. This ensures a sharp decrease in the low-temperature corrosion intensity, an increase in the operating reliability of condensation surfaces and the possibility of a sharp increase in the engine exhaust gas utilization depth to 80...90 °C instead of 160 °C. For the final gas cleaning, it was proposed to install a venturi scrubber and a cyclone-absorber on the gas path of ICE. Based on experimental studies, it has been established that the installation of a condensation heating surface in the EGB reduces the NOx content in gases by 55 %, SO2 - by 50 %, and the content of solid particles - by 3 times. The developed complex system can be used to clean the ICE gases to the level recommended by IMO.


Sign in / Sign up

Export Citation Format

Share Document