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, 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


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