The paper presents the results of simulations and experimental investigations on natural frequencies and oscillation modes of pairwise-shrouded cooled turbine blades and their rings with allowance for a possible frequency mistuning and the assured contact of mating surfaces of the root and shroud platform halves. As the research object, the high-pressure turbine wheel of an aircraft bypass turbojet engine has been selected. 3D finite element models of the turbine wheel blades/ period were developed as a system with structural rotational symmetry. The contact interaction between blades over the mating surfaces was modeled on basis of solving the stationary problem. The calculation-and-experimental investigations were performed for two operating conditions of the engine – the non-running engine and the steady-state maximum take-off condition. Results have been cited for individual, isolated blades. The results show a good agreement between calculated and experimental data. The frequency mistuning of those blades is found to be considerably dependent on oscillation mode number, but the mistuning value is practically not affected by the operating condition of the engine. It is confirmed that two oscillation modes are excited in the blade pair as a regular system in the presence of the mistuning of their frequencies, which are close to the inphase and antiphase frequencies. The ratio of natural frequencies of those oscillation modes is dependent on oscillation mode of isolated blades. It is shown that the frequency mistuning of paired blades due to excitation of two oscillation (inphase and antiphase) modes causes doubling of the number of resonant states of the turbine wheel what must be considered when developing methods to ensure their vibrational reliability.
Similar content being viewed by others
References
I. A. Birger and B. F. Shorr, Dynamics of Aircraft Gas-Turbine Engines [in Russian], Mashinostroenie, Moscow (1981).
V. T. Troshchenko, V. V. Matveev, B. A. Gryaznov, et al., The Load Capacity of Rotor Blades of Gas-Turbine Engines under Vibration Loading [in Russian], Naukova Dumka, Kiev (1981).
V. V. Matveev, Damping of Vibrations of the Deformed Solids [in Russian], Naukova Dumka, Kiev (1985).
A. P. Zin’kovskii, M. V. Smertyuk, V. V. Matveev, et al., “Resonance vibrations of turbine blades with sectional Christmas-tree roots,” Strength Mater., 16, No. 9, 1314–1319 (1984).
Yu. S. Vorob’ev, Vibrations of Turbine Machine Blading [in Russian], Naukova Dumka, Kiev (1985).
A. P. Zin’kovskii, A. Ya. Adamenko, I. N. Buslenko, and I. G. Tokar’, “Resonant vibrations of shrouded blades with differing frequencies with clapper interference,” Strength Mater., 26, No. 11, 821–824 (1994).
A. P. Zin’kovskii, M. V. Smertyuk, and V. V. Matveev, “Effect of disk compliance on the resonance vibrations of paired blades with frequency detuning,” Strength Mater., 18, No. 1, 68–75 (1986).
R. P. Pridorozhnyi, A.V. Sheremet’ev, and A. P. Zinkovskii, “Peculiar features of azimuth crystallographic orientation of turbine cooling rotor blades,” Vestn. Dvigatelestr., No. 1, 58–62 (2011).
V. P. Ivanov, Vibrations of Turbomachinery Rotors [in Russian], Mashinostroenie, Moscow (1983).
R. P. Pridorozhnyi, A. V. Sheremet’ev, and A. P. Zinkovskii, “Comparative analysis of the stress state of turbine cooling rotor blades using the calculated models of various levels,” Vestn. Dvigatelestr., No. 2, 183–187 (2011).
V. V. Bolotin (Ed.), Vibration in Engineering [in Russian], in 6 volumes, Vol. 1: Vibrations of Linear Systems, Mashinostroenie, Moscow (1978).
Yu. S. Vorob’ev, E. V. Tishkovets, V. A. Potanin, et al., “Vibration and statis strength of turbine compressor blades,” Aviats.-Kosm. Tekhn. Tekhnol., No. 40/5, 72–74 (2003).
Author information
Authors and Affiliations
Corresponding author
Additional information
Sheremet’ev is deceased
Translated from Problemy Prochnosti, No. 6, pp. 5 – 17, November – December, 2019.
Rights and permissions
About this article
Cite this article
Pridorozhnyi, R.P., Zinkovskii, A.P., Merkulov, V.M. et al. Calculation-and-Experimental Investigation on Natural Frequencies and Oscillation Modes of Pairwise-Shrouded Cooled Turbine Blades. Strength Mater 51, 817–827 (2019). https://doi.org/10.1007/s11223-020-00133-6
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11223-020-00133-6