Conformities analysis of heat transfer coefficient calculation from the gas at high-pressure turbines entry nozzle blade edges

Аuthors

Gorelov Y. G.^*, Strokach E. A.

Gas turbine engineering research and production center Salyut, 16, Budennogo av., Moscow, 105118, Russia

*e-mail: Yury.Dina@gmail.com

Abstract

At the preliminary design stage of gas-turbine engines and high-temperature gas-turbine power plants one should use criterion dependencies to evaluate heat transfer coefficients from the gas at entry nozzle blade edges. Analysis of various criterion dependencies revealed that for the majority of correlations under consideration the degree of gas flow turbulence behind the combustion chamber was about (1 - 5)%, though for modern gas-turbine engine and high-temperature gas- turbine power plants Tu = (15-20)%. Information that behind the gathering main preceding the first stage nozzle set the degree of turbulence ε= 3 … 4% is not confirmed by the data obtained by Thole K. A. et al, Gandavarapu P., Ames F.E., Ames F. E., Nix A. C. at al, and in the area of maximum temperature field circumferential non-uniformity behind the combustion chamber. Thus, the paper by Thole K. A. et al shows that according to experimental results, verified by experiments and calculations with aircraft combustion cameras is gives 19%.

To compare various design procedures and identify the margins of their implementation the presented paper carries out comparison of criterion dependencies for the averaged and maximum local heat exchange at the entry blade edge with the results of 3D conjugated numerical calculation using ANSYS CFX and 2D calculations of turboprop engine nozzle blade with entry blade increased diameter.

The results of various techniques comparison revealed that H. Consigny and B. E. Richards averaged heat exchange criterion dependence should be used to evaluate the entry blade edge perimeter averaged heat exchange coefficients from gas. To evaluate maximum over entry blade edge perimeter heat exchange coefficients from gas, and in in the zone of combustion chamber maximum circumferential non- uniformity in particular (T^*_g = 2100 К and Tu ≈  20%), maximum heat exchange criterion dependence should be used. This dependency was obtained by the results of heat exchange while straight cylinder flow-around study carried out by Ekkert E. R. and Drake. As far as it is necessary at the preliminary design stage of turboprop engine nozzle blades to evaluate, in the first place, their high-temperature strength for the applied material, this design stage requires the use of criterion dependence . Position of maximum heat transfer coefficients over perimeter of the entry edge and their outstretch along its bumpy surface depends on many factors: gas backstreaming angle, gas turbulence intensity (Tu) behind the combustion chamber, the value of maximum gas temperature field circumferential non-uniformity behind the combustion chamber, and others.

Thus their location should be determined for each particular blade at the stage of 3D conjugated numerical calculations. The data, hereafter, on maximum local heat exchange coefficients on the entry edge external surface are verified experimentally.

Keywords:

entry blade edge, heat-transfer coefficient, nozzle vane, high-pressure turbine, blade thermal state, thermal state analysis in ANSYS CFX

References

1. Manushin E.A., Baryshnikova E.S. Turbostroenie (Itogi nauki i tekhniki, VINITI AN SSSR). Moscow, VINITI, 1980, 277 p.

2. Kopelev S.Z., Gurov S.V. Teplovoe sostoyanie elementov konstruktsii aviatsionnykh dvigatelei (Thermal State of Aircraft Engine Elements), Moscow, Mashinostroenie, 1978, 208 p.

3. Kutateladze S.S., Borishanskii V.M. Spravochnik po teploperedache (Reference Book on Heat Transfer). Moscow — Leningrad, Gosenergoizdat, 1959, 414 p.

4. Lokai V.I., Bodunov M.N., Zhuikov V.V., Shchukin A.V. Teploperedacha v okhlazhdaemykh detalyakh gazoturbinnykh dvigatelei letatel’nykh apparatov (Heat Transfer in Cooled Parts of Gas Turbine Engines of Flying Vehicles), Moscow, Mashinostroenie, 1985, pp. 30-32 (288 p.).

5. Thole K.A., Radomsky R.W., Kang M.B. and Kohli A. Elevated Freestream Turbulence Effects on Heat Transfer for a Gas Turbine Vane,Turbulence Heat Transfer Conference, 18-22 March, 2001.

6. Gandavarapu P., Ames F.E. The Influence of leading edge diameter on stagnation region heat transfer augmentation including effects of turbulence level, scale, and Reynolds number, Proceedings of ASME Turbo Expo, June 610, 2011, Vancouver, British Columbia, Canada, ASME GT2011-45735.

7. Nix A.C., Smith A.C., Diller T.E., Ng W.F., Thole K.E. High Intensity, Large Length-Scale Freestream Turbulence Generation in a Transonic Turbine Cascade, Proceedings of ASME Turbo Expo, June 36, 2002, Amsterdam, Netherlands, ASME GT-2002-30523.

8. Ekkert E.R., Dreik R.M. Teoriya teplo– i massoobmena (Theory of Mass and Heat Transfer), Moscow Leningrad, Gosenergoizdat, 1961, 680 p.

9. Kuznetsov N.V. Teplovoi raschet kotel’nykh agregatov. <Normativnyi metod> (Thermal Calculation of Steam Generation Units <Normative Method>), Moscow, Energiya, 1973, 296 p.

10. Konsin’i i Richards. Energeticheskie mashiny i ustanovki, 1982, vol. 104, no. 3, pp. 12-22.

11. Byvaltsev P.M. and Nagashima Toshio. Correlation of Numerical and Experimental Heat Transfer Data at the Turbine Blade Surface. JSME International Journal, Series B, 1998, vol. 41, no. 1, pp. 191-199.

12. Byvaltsev P.M., Kawaike K.A. Comparative Study of Two transition Zone Models in Heat Transfer Predictions. Transactions of the ASME, Journal of Turbomachinery, 2005, vol. 127, no. 1, pp. 230-239.
    

13. Gorelov Yu.G. Izvestiya vuzov. Aviatsionnaya tekhnika, 2015, no. 1, pp.44-49.