Analysis of rotating coverplate receiver orifices influence on turbine cooling air supply system characteristics

2020 ◽  
Vol 12 (6) ◽  
pp. 271-281
Author(s):  
Roman Didenko ◽  
Shota Piralishvili ◽  
Valentin Shahov
Encyclopedia ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 893-904
Author(s):  
Krzysztof Marzec

Modern low-pressure turbine engines are equipped with casings impingement cooling systems. Those systems (called Active Clearance Control) are composed of an array of air nozzles, which are directed to strike turbine casing to absorb generated heat. As a result, the casing starts to shrink, reducing the radial gap between the sealing and rotating tip of the blade. Cooling air is delivered to the nozzles through distribution channels and collector boxes, which are connected to the main air supply duct. The application of low-pressure turbine cooling systems increases its efficiency and reduces engine fuel consumption.


Author(s):  
Gaowen Liu ◽  
Zhao Lei ◽  
Aqiang Lin ◽  
Qing Feng ◽  
Yan Chen

The pre-swirl system is of great importance for temperature drop and cooling air supply. This study aims to investigate the influencing mechanism of heat transfer, nonuniform thermodynamic characteristics, and cooling air supply sensitivity in a pre-swirl system by the application of the flow control method of the pre-swirl nozzle. A novel test rig was proposed to actively control the supplied cooling air mass flow rate by three adjustable pre-swirl nozzles. Then, the transient problem of the pre-swirl system was numerically conducted by comparison with 60°, 120°, and 180° rotating disk cavity cases, which were verified with the experiment results. Results show that the partial nozzle closure will aggravate the fluctuation of air supply mass flow rate and temperature. When three parts of nozzles are closed evenly at 120° in the circumferential direction, the maximum value of the nonuniformity coefficient of air supply mass flow rate changes to 3.1% and that of temperature changes to 0.25%. When six parts of nozzles are closed evenly at 60° in the circumferential direction, the maximum nonuniformity coefficient of air supply mass flow rate changes to 1.4% and that of temperature changes to 0.20%. However, different partial nozzle closure modes have little effect on the average air supply parameters. Closing 14.3% of the nozzle area will reduce the air supply mass flow rate by 9.9% and the average air supply temperature by about 1 K.


2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.


1992 ◽  
Vol 91 (5) ◽  
pp. 3083-3083
Author(s):  
Marian W. Dobry ◽  
Czeslaw Cempel ◽  
Wieslaw Garbatowski

Author(s):  
Oliver Popp ◽  
Horst Zimmermann ◽  
J. Kutz

The flow field in a preswirled cooling air supply to a turbine rotor has been investigated by means of CFD-simulations. Coefficients for system efficiency are derived. The influences of various geometrical parameters for different configurations have been correlated with the help of appropriate coefficients. For some of the most important geometrical parameters of the coverplate receiver design recommendations have been found. For the preswirl nozzles the potential of efficiency improvement by contour design is highlighted.


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