scholarly journals The vibration of prototype aircraft propeller speed reduction unit – test bench and FEM numerical simulation study

2014 ◽  
Vol 62 (4) ◽  
pp. 861-873
Author(s):  
W. Ostapski ◽  
A. Aromiński ◽  
S. Dowkontt
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Engine Speed ◽  
3D Model ◽  
Test Bench ◽  
Normal Modes ◽  
The Finite Element Method ◽  
Speed Reduction ◽  
Bench Tests ◽  
Lubrication Conditions

Abstract The results of torsional shaft vibration bench tests for a prototype aircraft propeller speed reduction unit are presented in this paper. The study was conducted as a function of engine speed and lubrication conditions. 3D model of the propeller speed reduction unit was developed. By using the finite element method, normal modes frequencies were defined. The simulation was conducted both unloaded and loaded under nominal power conditions.

Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

2019 ◽  
pp. 36-42
Author(s):  
A. P. Shaikin ◽  
I. R. Galiev
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Power Plants ◽  
Engine Speed ◽  
Combustion Engine ◽  
Fuel Mixture ◽  
Maximum Pressure ◽  
Chamber Volume ◽  
Excess Air ◽  
Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

Observer-based output tracking of engine speed and torque reserve at idle with sliding mode control

2007 ◽  
Author(s):  
Benedikt Alt ◽  
Jan Peter Blath ◽  
Klaus-Dieter Otto ◽  
Ferdinand Svaricek ◽  
Matthias Schultalbers
Keyword(s):  
Sliding Mode Control ◽  
Engine Speed ◽  
Sliding Mode ◽  
Output Tracking ◽  
Mode Control
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