Efficiency of film cooling the concave surface of an aircraft gas turbine nozzle blade exposed to pulsed blowing through the fan-shaped holes

The paper presents results of experimental studies to determine the efficiency of film cooling concave surface of the aircraft engine turbine nozzle blade profile with pulsating injection of the secondary air flow through a series of the fan-shaped holes. It uses the data obtained after injection through the cylindrical holes under the otherwise equal conditions as the base data. The secondary air flow is injected at the angles of 30, 45, and 75 degrees. The secondary air flow pulsation frequency is 14 Hz, relative curvature of the concave surface — 0.00574, the secondary flow Reynolds number — (0.4…7.6)??104, and that of the main flow – 2.6?105. The injection parameter (numerical values determined by the hole inlet section) vary in the range of 0.5…2.0, the relative distance from the injection section — in the interval of 1…37. Analyzing the experimental results shows that in all the studied modes on a concave surface, injection through the fan-shaped holes provides higher efficiency of film cooling than through the cylindrical holes. Under the considered conditions, different trends in alteration of relative efficiency in the concave surface film cooling with an increase in the relative distance from the injection section are observed in the transition and main mixing sections of the thermal curtain. Unequal values of this parameter are caused by the difference in the mass transfer process between the main and secondary flows formed by the fan-shaped and cylindrical holes.
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References

[1] Inozemtsev A.A., Nikhamkin M.A., Sandratskiy V.L. Osnovy konstruirovaniya aviatsionnykh dvigateley i energeticheskikh ustanovok. T. 2 [Fundamentals of design of aircraft engines and power plants. Vol. 2]. Moscow, Mashinostroenie Publ., 2008. 366 p. (In Russ.).

[2] Danilchenko V.P., Lukachev S.V., Kovylov Yu.L. et al. Proektirovanie aviatsionnykh gazoturbinnykh dvigateley [Design of aviation gas-turbine engines]. Samara, Izd-vo SNTs RAN Publ., 2008. 619 p. (In Russ.).

[3] Gorelov Yu.G., Tyulkov K.V. [3D investigation of film cooling effectiveness for turbine nozzle vane with cylindrical, fan shaped and laidback fan-shaped film-cooling holes in adiabatic and conjugate conditions]. Problemy i perspektivy razvitiya dvigatelestroeniya. Mat. dok. mezhd. nauch-tekh. konf. Ch. 1 [Problems and Prospects of Engine Building Development. Proc. Int. Sci.-Tech. Conf. P. 1]. Samara, Samarskiy un-t Publ., 2016, pp. 9–11. (In Russ.).

[4] Hada S., Yuri M., Masada J.et al. Evolution and future trend of large frame gas turbines: a new 1600 degree C, J class gas turbine. Proc. ASME Turbo Expo, 2012, paper no. GT2012-68574, pp. 599–606, doi: https://doi.org/10.1115/GT2012-68574

[5] Shchukin A.V., Ilinkov A.V., Takmovtsev V.V. et al. Teplofizika rabochikh protsessov v okhlazhdaemykh lopatkakh gazovykh turbin [Thermophysics of working processes in cooled blades of gas turbines]. Kazan, Izd-vo KNITU-KAI Publ., 2020. 390 p. (In Russ.).

[6] Vinogradov K.A. Povyshenie effektivnosti gazovoy turbiny putem strukturno-parametricheskoy optimizatsii obvodov perekhodnogo kanala i formy otverstiy plenochnogo okhlazhdeniya. Diss. kand. tekh. nauk [Increase of a gas turbine efficiency by structural and parametric optimization of transition channel outline and shape of film cooling holes. Kand. tech. sci. diss.]. Rybinsk, RGATU Publ., 2015. 168 p. (In Russ.).

[7] Khalatov A.A., Borisov I.I., Dashevskiy Yu.Ya. et al. Teploobmen i gidrodinamika v polyakh tsentrobezhnykh massovykh sil. T. 10. Perspektivnye skhemy plenochnogo okhlazhdeniya [Heat exchange and hydrodynamics in fields of centrifugal mass forces. Vol. 10. Perspective schemes of film cooling]. Kiev, NTUU KPI Publ., Politekhnika Publ., 2016. 238 p. (In Russ.).

[8] Li X.C., Subbuswamy G., Zhou J. Performance of gas turbine film cooling with backward injection. Energy Power Eng., 2013, no. 5, pp. 132–137, doi: https://doi.org/10.4236/epe.2013.54B025

[9] Saumveber C., Schulz A., Wittig S. Free-stream turbulence effects on film cooling with shaped holes. J. Turbomach., 2003, vol. 125, no. 1, pp. 65–73, doi: https://doi.org/10.1115/1.1515336

[10] Wright M., McClaine S., Clemenson M.D. Effect of density ratio on flat plate film cooling with shaped holes using PSP. Proc. ASME Turbo Expo, 2010, paper no. GT2010-23053, pp. 1691–1702, doi: https://doi.org/10.1115/GT2010-23053

[11] Li W., Li X., Ren J., Jiang H. Experimental investigation of wall thickness and hole shape variation effects on full-coverage film cooling performance for a gas turbine vane. Appl. Therm. Eng., 2018, no. 144, pp. 349–361, doi: https://doi.org/10.1016/j.applthermaleng.2018.08.068

[12] Shchukin A.V., Ilinkov A.V., Takmovtsev V.V. et al. The effectiveness of film cooling with injection of pulsating air flow (review). Teploenergetika, 2023, no. 9, pp. 5–17, doi: https://doi.org/10.56304/S0040363623090060 (in Russ.). (Eng. version: Therm. Eng., 2023, vol. 70, no. 9, pp. 639–649., doi: https://doi.org/10.1134/S0040601523090069)

[13] Lutum E., Wolfersdorf J., Semmler K. et al. Film cooling on a concave surface: influence of external pressure gradient on film cooling performance. Proc. NATO/AGARD Symposium on Advanced Flow Management. Part B. Heat Transfer and Cooling in Propulsion and Power Systems, 2001, URL: https://www.researchgate.net/publication/235088269 (accessed: 16.06.2024).

[14] Lu Y., Dhungel A., Ekkad V. et al. Effect of trench width and depth on film cooling from cylindrical holes embedded in trenches. J. Turbomach., 2009, vol. 131, no. 1, art. 011003, doi: https://doi.org/10.1115/1.2950057

[15] Ilinkov A.V., Takmovtsev V.V., Tukmakov A.L. et al. Efficiency of heat shield generated by blowing the pulsating airflow through one-row bands of holes. Aviatsionnaya tekhnika, 2022, no. 4, pp. 139–145. (In Russ.). (Eng. version: Russ. Aeronaut., 2022, vol. 65, no. 4, pp. 791–798, doi: https://doi.org/10.3103/S1068799822040201)

[16] Ekkad S.V., Ou S., Rivir R.B. Effect of jet pulsation and duty cycle on film cooling from a single jet on a leading edge model. J. Turbomach., 2006, vol. 128, no. 3, pp. 564–571, doi: https://doi.org/10.1115/1.2185122