Geodesic
Numeracal simulation of gas flow in a "stage-diffuser" system in a wide range of modes with experimental verification
Matematičeskoe modelirovanie, Tome 36 (2024) no. 2, pp. 41-52 Cet article a éte moissonné depuis la source Math-Net.Ru

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Usually at the design stage of a gas turbine the nominal operating mode is considered. This mode is defined by the axial exit of the flow from the turbine, in order to reduce losses with the exhaust velocity. Axial entry into the diffuser is optimal, due to absence of attack angles on the power struts. Struts are the integral part of the diffuser, where the rear bearing support of the turbine rotor is located. However, gas turbine operates for a long time both in nominal and in variable modes. Partial modes are characterized by significant attack angles on the struts, which leads to flow separation and notable increase in pressure losses in the diffuser. Maintaining a satisfactory flow in the diffuser in the wide range of modes is an important issue. In this investigation the stage-diffuser system was studied by experimental and numerical methods at wide range of modes. Study has shown that at the last stage flow angle less than 50 degrees, the flow in the diffuser acquires an asymmetric character with developed vortices. This means that numerical simulation in an engineering approach cannot repeat the nature of the flow at low load modes. Nevertheless, a comparison of the experiment and simulation total parameters shows good agreement (a difference of about 5%) even for modes with large attack angles on the diffuser struts.
Mots-clés : diffuser
Keywords: turbine stage, exhaust nozzle, aerodynamics, pressure losses, partial load modes. 
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M. G. Cherkasova; V. A. Chernikov; E. Yu. Semakina. Numeracal simulation of gas flow in a "stage-diffuser" system in a wide range of modes with experimental verification. Matematičeskoe modelirovanie, Tome 36 (2024) no. 2, pp. 41-52. http://geodesic.mathdoc.fr/item/MM_2024_36_2_a2/

[1] S. Hummel, M. Bauer, D. Vogt, “Study of gas turbine exhaust diffuser flow and performance characteristics at off-design conditions”, 14th European Conference on Turbomachinery Fluid Dynamics Thermodynamics, 2021

[2] M. Bauer, S. Hummel, M. Schatz, M. Kegalj, D. Vogt, “Investigation of the Flow Field and the Pressure Recovery in a Gas Turbine Exhaust Diffuser at Design, Part-load and Over-load Condition”, Proceedings of ASME Turbo Expo, 2020, GT2020-14310

[3] K. Brown, S. Guillot, L. Iksang, K. Dongil, G. Hong, “Experimental Investigation of Gas Turbine Axial Diffuser Performance. P. II: Effect of Inlet Flow Profiles at On- and Off-Design Conditions”, Proc. of ASME Turbo Expo, 2020, GT2020-15305

[4] V. Dossena, G. Persico, B. Paradiso, C. Bettini, C. Canelli, S. Cecchi, F. Dacca, “Investigation of the Flow Field in a Gas Turbine Exhaust Diffuser at Design and Part Load Conditions”, Proc. of the 1st Global Power and Propulsion Forum, GPPF-2017-32

[5] S. A. Galaev, A. I. Kirillov, E. M. Smirnov, D. O. Panov, “Chislennoe modelirovanie nestatsionarnogo techeniia i teploobmena v vykhodnom diffuzore gazovoi turbiny”, Nauchno-tekhnicheskie vedomosti SPbPU, 2016, no. 254, 59–68

[6] L. O. Vokin, E. Iu. Semakina, V. A. Chernikov, “Vliianie zakrutki lopatok poslednei stupeni na effektivnost bloka «stupen-diffuzor» statsionarnoi GTU”, Izvestiia vysshikh uchebnykh zavedenii. Problemy energetiki, 23:4 (2021), 84–95

[7] V. A. Chernikov, “Eksperimentalnyi stend dlia gazodinamicheskikh issledovanii vykhodnykh diffuzorov i patrubkov turbin”, Teploenergetika, 2008, no. 6, 49–54

[8] M. G. Cherkasova, E. Iu. Semakina, V. A. Chernikov, “Validatsiia chislennogo metoda issledovaniia sistemy «stupen-diffuzor» i ego ispolzovanie dlia modernizatsii konstruktsii”, Vestnik Samarskogo universiteta. Aerokosmicheskaia tekhnika, tekhnologii i mashinostroenie, 21:2 (2022), 38–47