Engine speed reduction for hydraulic machinery using predictive algorithms

2019 ◽  
Vol 2 (1) ◽  
pp. 16 ◽  
Author(s):  
Travis Wiens
2014 ◽  
Vol 62 (4) ◽  
pp. 861-873
Author(s):  
W. Ostapski ◽  
A. Aromiński ◽  
S. Dowkontt

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.


Author(s):  
A. P. Shaikin ◽  
I. R. Galiev

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.


Author(s):  
Benedikt Alt ◽  
Jan Peter Blath ◽  
Klaus-Dieter Otto ◽  
Ferdinand Svaricek ◽  
Matthias Schultalbers

1944 ◽  
Vol 151 (1) ◽  
pp. 70-86
Author(s):  
W. Littlejohn Philip

The paper is limited to the application of hydraulic power to lathes designed for shell making although, in the author's opinion, there is an immense field for the application of the same principles in other directions. Self-contained hydraulic machine tools have been dealt with by Mr. H. C. Town,† but in the system to be described all the machines are operated from a central hydraulic plant. Three complete installations on this principle have been established by the author, and the present paper contains an account of this work from the first experiments in 1915 until about four years ago. The first plant was constructed in 1915 for the production of 3·29-inch shells, known as “18-pounders”, from the solid bar. The output was 2,000 shells per week of 135 hours, with girl operators working on three shifts. The second plant was put down in 1916–17 for an output of 500 9·2-inch howitzer shells per week of 135 hours, also with girls working on three shifts. The third plant is of recent design. It was started in 1938 for the production of 3·45-inch shells, known as “25-pounders”; and was laid out for an output of 1,000 shells per week of 47 hours. This plant included four types of hydraulic lathes which the author was engaged to design for the War Office. Soon after the commencement of the last war in 1914 it became evident that shell production would have to be greatly increased, and engineering firms were pressed to take up shell manufacture. The author, on behalf of his firm, undertook to help in the movement, and he at once set about the construction of some simple machines for the job. These conformed on general lines to the practice of the period as regards design and operation. He soon realized, however, that drastic changes would have to be made if production was to reach the high level that circumstances demanded. Although quite familiar with hydraulic machinery of various types and of many applications in presses and certain types of heavy tools, he was not aware of any instance in which hydraulic power had been applied to the movements of a lathe. It appeared to him, nevertheless, that it would be possible to construct a very useful machine on these lines, and he accordingly started immediately to carry out experiments and to prepare designs. It was considered essential that machines for the duty which the author had in mind should be much heavier and more rigid than the ordinary machines of the time, so that they should be free from vibration and “chatter” or spring with the heaviest possible cutting. The standard of rigidity aimed at was that which would permit a half-crown coin to remain balanced on edge on the moving saddle or turret while the tools were making the heaviest cuts. This object was achieved, and the demonstration was frequently made in the presence of those who came to see the lathes at work.


2021 ◽  
Vol 11 (4) ◽  
pp. 1742
Author(s):  
Ignacio Rodríguez-Rodríguez ◽  
José-Víctor Rodríguez ◽  
Wai Lok Woo ◽  
Bo Wei ◽  
Domingo-Javier Pardo-Quiles

Type 1 diabetes mellitus (DM1) is a metabolic disease derived from falls in pancreatic insulin production resulting in chronic hyperglycemia. DM1 subjects usually have to undertake a number of assessments of blood glucose levels every day, employing capillary glucometers for the monitoring of blood glucose dynamics. In recent years, advances in technology have allowed for the creation of revolutionary biosensors and continuous glucose monitoring (CGM) techniques. This has enabled the monitoring of a subject’s blood glucose level in real time. On the other hand, few attempts have been made to apply machine learning techniques to predicting glycaemia levels, but dealing with a database containing such a high level of variables is problematic. In this sense, to the best of the authors’ knowledge, the issues of proper feature selection (FS)—the stage before applying predictive algorithms—have not been subject to in-depth discussion and comparison in past research when it comes to forecasting glycaemia. Therefore, in order to assess how a proper FS stage could improve the accuracy of the glycaemia forecasted, this work has developed six FS techniques alongside four predictive algorithms, applying them to a full dataset of biomedical features related to glycaemia. These were harvested through a wide-ranging passive monitoring process involving 25 patients with DM1 in practical real-life scenarios. From the obtained results, we affirm that Random Forest (RF) as both predictive algorithm and FS strategy offers the best average performance (Root Median Square Error, RMSE = 18.54 mg/dL) throughout the 12 considered predictive horizons (up to 60 min in steps of 5 min), showing Support Vector Machines (SVM) to have the best accuracy as a forecasting algorithm when considering, in turn, the average of the six FS techniques applied (RMSE = 20.58 mg/dL).


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