Gas dynamic and strength tuning of low-sized axial turbine

Аuthors

Popov G. M.^*, Kolmakova D. A.^**, Krivcov A. V.^***

Samara National Research University named after Academician S.P. Korolev, 34, Moskovskoye shosse, Samara, 443086, Russia

*e-mail: popov@ssau.ru
**e-mail: kolmakova.daria@gmail.com
***e-mail: krivcov63@mail.ru

Abstract

The research subject of the present paper is a single-stage axial turbine of the turbocharger TK-32. Turbocharger is manufactured by LLC «Penzadieselmash» (Penza, Russian) and used as unit supercharge for locomotive diesel. The aim of this work is to ensure the turbine work capacity when rotor speed is increased by 10% without significant reduction of safety margin and coefficient of efficiency.
The workflow gas-dynamic analysis of turbocharger TK-32 turbine stage and the stress strain state calculation of its rotor blade in base variant at nominal mode (n=25500 rpm) and at forced mode (n=28000 rpm) were carried out in the given work. The conducted strain-stress state analysis at forced mode indicated the region of high stresses on turbine rotor blade at the level of 2/3 from root. The stresses are exceeding permissible. In addition, it was revealed the presence of plastic deformation in the attachment of the disk and blades.
The variant of the turbine modernization was proposed based on the performed strength and gas-dynamic computational studies. The peripheral rotor blade section tangential displacements were implemented to create a modernized turbine design. It is allowed to reduce the level of stresses almost by 20%. The derived value of safety margin of modernized turbine at the forced mode is not below the value of safety margin for base turbine version at nominal conditions. The flow in the turbine modernized in accordance with the received recommendations was investigated using Ansys CFX. The calculation showed that the coefficient efficiency of an improved turbine is increased by more than 1% compared with the original value.
Experimental results showed an increase in turbine efficiency which fully confirms the conclusions drawn by the authors.

Keywords:

turbocharger, stress-strain behavior, assurance factor, the gas-dynamic analysis

References

Popov, G.M., Baturin O.V. Vestnik Samarskogo gosudarstvennogo aerokosmicheskogo universiteta im. akademika S.P. Koroleva (natsional’nogo issledovatel’skogo universiteta), 2009, no. 3(2), pp. 365-368.


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