AIR SUPPLY SYSTEMS

1969 ◽  
pp. 113-125
Author(s):  
J. FLACK ◽  
A.J.S. BENNETT ◽  
R. STRONG ◽  
LEONARD J. CULVER
Keyword(s):  
Air Supply ◽  
Supply Systems

Turbine Stator Well CFD Studies: Effects of Coolant Supply Geometry on Cavity Sealing Performance

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Antonio Andreini ◽  
Riccardo Da Soghe ◽  
Bruno Facchini
Keyword(s):  
Air Cooling ◽  
Sector Model ◽  
Engine Efficiency ◽  
Air Supply ◽  
Sealing Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Cooling Air ◽  
Supply Systems

The increase of aeroengine performance through the improvement of aerodynamic efficiency of core flow is becoming more and more difficult to achieve. However, there are still some devices that could be improved to enhance global engine efficiency. Particularly, investigations on the internal air cooling systems may lead to a reduction of cooling air with a direct benefit to the overall performance. At the same time, further investigations on heat transfer mechanisms within turbine cavities may help to optimize cooling air flows, saving engine life duration. This paper presents a computational fluid dynamics (CFD) study aimed at the characterization of the effects of different geometries for cooling air supply within turbine cavities on wall thermal effectiveness and sealing mass flow rate. Several sealing air supply geometries were considered in order to point out the role of cooling air injection position, swirl number, and jet penetration on the cavities’ sealing performance. Steady state calculations were performed using two different computational domains: the first consists of a sector model of the whole turbine including the second stator well, while the second is a cut-down model of the stator well. Thanks to the simplified geometry of the test rig with respect to actual engines, the study has pointed out clear design suggestions regarding the effects of geometry modification of cooling air supply systems.

scholarly journals Nonlinear dynamics of self-organising bubble departures from twin nozzles

Meccanica ◽  
2019 ◽  
Vol 54 (14) ◽  
pp. 2119-2130 ◽  
Author(s):  
P. Dzienis ◽  
R. Mosdorf ◽  
T. Wyszkowski
Keyword(s):  
Nonlinear Dynamics ◽  
High Speed ◽  
Air Pressure ◽  
Air Bubbles ◽  
Pressure Oscillations ◽  
Engine Oils ◽  
Air Supply ◽  
Inner Diameter ◽  
The Mean ◽  
Supply Systems

Abstract The nonlinear dynamics of self-organising bubble departures from twin nozzles in engine oils was analysed. Air bubbles were generated from twin brass nozzles with an inner diameter equal to 1 mm. The flow of bubbles in bubble chains was recorded using high-speed camera. The time series of air pressure oscillations and signal from laser–phototransistor identifying the presence of bubbles over the nozzles outlet were recorded simultaneously. The self-organising bubble departures were observed and their stability was analysed. It was found that self-organising bubble departures become unstable because of successive (during subsequent bubble departures) decrease of the mean air pressure in one of the nozzle air supply system. It was shown that instability of self-organising bubble departures leads to equalization of pressures in both nozzles air supply systems which causes that simultaneous bubble departures appear. In the present experiment, this process was repeated in a cyclic and chaotic way. It was shown that stable self-organising bubble departures are accompanied by periodic air pressure oscillations in one of the nozzles and chaotic air pressure oscillations in the second one.

Improving the energy efficiency of a 6ChN13/15 gas engine with a Miller cycle by optimizing the valve timing

Trudy NAMI ◽  
2022 ◽  
pp. 41-52
Author(s):  
A. V. Kozlov ◽  
V. A. Fedorov ◽  
K. V. Milov
Keyword(s):  
Numerical Modeling ◽  
Thermodynamic Cycle ◽  
Practical Significance ◽  
Miller Cycle ◽  
Gas Distribution ◽  
Gas Engine ◽  
Model Studies ◽  
Air Supply ◽  
Scale Experiment ◽  
Supply Systems

Introduction (problem statement and relevance). The object of research in this work is an inline six-cylinder gas engine 6ChN13/15 with a Miller thermodynamic cycle. On the basis of its computer model studies minimization of the specific effective fuel consumption has been reached due to variation study of gas distribution and air supply systems parameters.The purpose of the study was to investigate the parameters regulation effect of gas distribution and air supply systems on the performance of a 6ChN13/15 gas engine with a Miller cycle on the external speed characteristic basing on numerical modeling.Methodology and research methods. The research was carried out by the method of computer simulation. Numerical modeling was made on the basis of data obtained during a full-scale experiment of a 6ChN13/15 gas engine with Miller thermodynamic cycle.Scientific novelty and results. A comparative analysis of a gas engine optimization results has been carried out. The results obtained will be used to create a gas engine and its further optimization by controlling the working process and the air supply system.Practical significance. The results obtained may be of interest to truck car manufacturers and engine specialists.

Risks of Violation of the Microclimate in Protective Structures (Shelters)

2020 ◽  
Vol 17 (5) ◽  
pp. 26-33
Author(s):  
R. D. Oktyabrskiy
Keyword(s):  
Design Parameters ◽  
Outdoor Air ◽  
Air Supply ◽  
Temperature And Humidity ◽  
Reduce Risk ◽  
Methodological Approaches ◽  
Protective Structures ◽  
Supply Systems ◽  
Selection Of

The article discusses one of the problems associated with the vulnerability of the population, as well as the personnel of hazardous industries, who are sheltering in protective structures (shelters) in case of emergency threats (emergencies) of a peaceful and military nature. The problem consists in the existing risk of violation of the permissible temperature and humidity parameters of the air in the shelter.Based on the analysis of the laws of climate and the duration of the period of autonomy of protective structures, methodological approaches to the selection of design parameters of outdoor air for the design of air supply systems of protective structures are substantiated.To estimate the effectiveness of the selected outdoor air parameters over reduce risk, a criterion is proposed: the probability of not violating the permissible microclimate in the protective structures.

scholarly journals DYNAMICS OF MOTION OF GASES FROM A SOURCE OF SPONTANEOUS COMBUSTION OF COAL IN MINE WORKINGS

2021 ◽  
Vol 36 (2) ◽  
pp. 109-117
Author(s):  
Viktor Kostenko ◽  
Yuriy Gamiy ◽  
Tetiana Kostenko ◽  
Sergii Tsvirkun ◽  
Maksym Udovenko
Keyword(s):  
Coal Mine ◽  
Spontaneous Combustion ◽  
Gas Flows ◽  
Fire Dynamics ◽  
Self Heating ◽  
Air Supply ◽  
Gas Hazard ◽  
Mine Workings ◽  
Metric Dimensions ◽  
Supply Systems

The object of this paper is to study the specificity of the dynamics of carbon monoxide in mining to determine the location of the source of coal self-heating or spontaneous combustion. The Fire Dynamics Simulator software package was used to model the gas hazard of coal mine workings. Given the typical details for the western coal basin of Donbas geo metric dimensions of workings, properties of coal, etc., a model of a fragment of emergency mining of a coal mine was created, which allows for the display of geometric and physical similarity to processes in actual mine workings. The results of the simulation for the studied scenarios with different air supply systems related to the detection and location of sources of self-heating or spontaneous combustion in the coal mine workings were obtained and analysed. It was established that low-density fire gases are concentrated in the vault of the workings, where they slowly dissolve in the air, with the dissolution process being linear. It was revealed that air velocity up to 0.67 to 0.7 m/s contributes to the formation of fire gas flows, which move towards the ventilation flow, almost without mixing, which is referred to as bifurcation. Numerical parameters of fire gas dynamics in near-real conditions were established, which can become a basis for the detection and location of sources of endogenous thermodynamic processes in mine workings.

Minimised Gear Lubrication by a Minimum Oil/Air Flow Rate

2007 ◽  
Author(s):  
Bernd-Robert Ho¨hn ◽  
Klaus Michaelis ◽  
Hans-Philipp Otto
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Load Carrying Capacity ◽  
Air Supply ◽  
Load Carrying ◽  
Air Lubrication ◽  
Oil Flow ◽  
Application Potential ◽  
Supply Systems

The objectives of the research project were to investigate the limits concerning possible reduction of lubricant quantity in gears without detrimental influence on the load carrying capacity. The investigations covered the influence of the oil level in dip lubricated systems as well as the oil flow rate in spray lubricated systems namely oil-air supply systems on power loss, heat generation and load carrying capacity. The load carrying capacity in terms of characteristic gear failure modes was determined and was compared to the results using conventional lubricant volumes with dip lubrication. Therefore in back-to-back gear tests the parameters speed, load and oil quantity were varied for examination of the four main gear flank damages: scuffing, wear, pitting and micropitting. The investigations showed the application potential of oil/air lubrication also for heavy duty transmissions nevertheless there exists a natural limitation for lowering the oil quantity in transmissions without detrimental influence on the load carrying capacity.

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