Gas dynamic optimization of wedge-shape vaned diffuser of a centrifugal compressor of small-sized turbojet engines based on numerical modelling

Aeronautical and Space-Rocket Engineering

Thermal engines, electric propulsion and power plants for flying vehicles

DOI: 10.34759/vst-2019-4-134-143


Varsegov V. L.*, Abdullah B. N.**

Kazan National Research Technical University named after A.N. Tupolev, KNRTU-KAI, 10, Karl Marks str., Kazan, 420111, Russia



A competitive small-sized turbojet engine development under modern conditions of aviation engines building requires high efficiency values of parts with high degree of pressure ratio. Centrifugal compressors find extensive application while developing small-sized gas turbine engines employed for unmanned aerial vehicles and gas turbine power plants.

To ensure high efficiency and compressor pressure ratio, a numerical gas-dynamic calculation is performed with Ansys Workbench (Fluid flow CFX) program, which allows studying the air flow in the diffuser channels.

The presented article considers the flow in a wedge­shaped diffuser and optimize geometry optimization of the wedge-shaped diffusers blades of a centrifugal compressor, as well as geometry impact on the total pressure loss coefficient ξ, and the coefficient of static pressure recovery in the diffuser Cp at different entry angles α3l .

The main task of the calculation consists in determining the optimal shape of the wedge-shaped diffuser blades, insuring required parameters and characteristics of the diffuser, with an uninterrupted flow and a minimum of energy loss at given input angles.

The article presents also the results of the compressor stage numerical study, i.e. joint operation of the impeller with a diffuser to assess the quality of the geometry and operation of the diffuser to increase the compressor efficiency.

In the presented work, the calculation model is built with the SolidWorks program, and then, using the Turbo Grid program, the computational grid was applied. The flow simulation was performed using the SST turbulent viscosity model.


small-sized turbojet engine, diffuser, centrifugal compressor, geometry optimization, total pressure loss coefficient, total pressure recovery coefficient


  1. Chumakov Yu. A. Gazodinamicheskii raschet tsentrobezhnykh kompressorov transportnykh i kombinirovannykh dvigatelei (Gas- dynamic calculation of centrifugal compressors for transport gas turbine and combined engines), Moscow, MAMI, 2009, 72 p.

  2. Osipov I.V., Remchukov S.S. Small-size gas turbine engine with free turbine and heat recovery system heat exchanger within the 200 HP power class. Aerospace MAI Journal, 2019, vol. 26, no. 2, pp. 81-90.

  3. Shcherbakov M.A., Yun A.A., Marchukov E.Yu., Krylov B.A. The use of modern CFD software packages for nozzle jet engine computation. Aerospace MAI Journal, 2010, vol. 17, no. 5, pp. 116-120.

  4. Shcherbakov M.A., Yun A. A., Krylov B.A. A comparative analysis of turbulence models using Fastest-SD scientific code and ANSYS CFX commercial software package. Aerospace MAI Journal, 2009, vol. 16, no. 5, pp. 116-122.

  5. Sha M., Agul’nik A.B., Yakovlev A.A. The effect of the computational mesh while mathematical modeling of the inflow of a subsonic flow onto the profile of a perspective blade with a deflectable trailing edge in a three-dimensional setup. Aerospace MAI Journal, 2017, vol. 24, no. 4, pp. 110-121.

  6. Kostyukov V.M., Tran Q.D. Turbulence model validation for calculation of flow parameters and aerodynamic characteristics of a passenger plane. Aerospace MAI Journal, 2015, vol. 22, no. 1, pp. 14-20.

  7. Nesterenko V.V. First principles of methodology of integrated optimization of image and parameters in hot section of gas turbine turboshaft engine. Aerospace MAI Journal, 2009, vol. 16, no. 6, pp. 82-92.

  8. Baturin O.V. Konspekty lektsii po uchebnoi distsipline “Teoriya i raschet lopatochnykh mashin ” (Lecture notes on the academic discipline “Theory and calculation of blade machines: study guide, manual”), Samara, SGAU, 2011, 241 p.

  9. Denisov M.A. Matematicheskoe modelirovanie teplofizicheskikh protsessov. ANSYS i SAE-proektirovanie (Mathematical modeling of thermo-physical processes. ANSYS and CAE-design), Ekaterinburg, UrFU, 2011, 149 p.

  10. Mileshin V.I., Semenkin V.G. Computational study of Reynolds number effect on the typical first stage of a high-pressure compressor. Aerospace MAI Journal, 2018, vol. 25, no. 2, pp. 86-98.

  11. Rzhavin Yu.A., Emin O.N., Karasev V.N. Lopatochnye mashiny dvigatelei letatel’nykh mashin. Teoriya i raschet (Aircraft engines impeller machines. Theory and calculation), Moscow, MAI-PRINT, 2008, 700 p.

  12. Gusarov S.A. Trudy MAI, 2012, no. 53. URL:

  13. Garbaruk A.V., Strelets M.Kh., Shur M.L. Modelirovanie turbulentnosti v raschetakh slozhnykh techenii (Aircraft engines impeller machines. Theory and calculation), St. Petersburg, Politekhnicheskii institut, 2012, 88 p.

  14. Ledovskaya N.N. Upravlenie otryvom potoka v diffuzionnykh kanalakh. Eksperimental’noe issledovanie (Flow separation control in diffusion channels. Experimental research), Moscow, Doctor’s thesis, TsIAM im. Baranova, 2004, 156 p.

  15. Belousov A.N., Musatkin N.F., Rad’ko V.M., Kuz’michev V.S. Proektnyi termogazodinamicheskii raschet osnovnykh parametrov aviatsionnykh lopatochnykh mashin (Design thermo-gas-dynamic calculation of the aircraft blade machines main parameters), Samara, Samarskii aerokosmicheskii universitet, 2006, 316 p.

  16. Kuznetsov E.N., Lunin V.Yu., Panyushkin A.V., Chernyshev I.L. Boundaries of non-separation flow- around of bodies of rotation, with the nose part in the form of Riabouchinsky half-cavity. Aerospace MAI Journal, 2018, vol. 25, no. 4, pp. 7-15.

  17. Ivanov I.E., Kryukov I.A. Numerical investigations of turbulent flows with free and restricted shock separation. Aerospace MAI Journal, 2009, vol. 16, no. 7, pp. 23-30.

  18. Kryukov I.A. A computation of turbulent supersonic flows. Aerospace MAI Journal, 2009, vol. 16, no. 2, pp. 101-108.

  19. Bonaiuti D., Arnone A., Ermini M., Baldassarre L. Analysis and Optimization of Transonic Centrifugal Compressor Impellers Using the Design of Experiments Technique. Journal of Turbomachinery, 2006, vol. 128, no. 4, pp. 786-797. DOI: 10.1115/1.1579507

  20. Tamaki H., Nakao H., Saito M. The Experimental Study of Matching Between Centrifugal Compressor Impeller and Diffuser ASME. Journal of Turbomachinery, 1999, vol. 121, no. 1, pp. 113-118. DOI: 10.1115/1.2841218 — informational site of MAI

Copyright © 1994-2023 by MAI