Present paper deals with numerical simulation of flow in simplified model of the axial turbine stage equipped with the hub-seal. Main subject of simulations is study of various geometrical modifications of the outlet-slot from the hub-seal. The purpose of these modifications is to suppress a negative effect of complex secondary structures on the stage efficiency. Secondary flow structures are formed as a result of interaction of main stream above the outlet-slot with the leakage-stream from the hub-seal. It was found that suitable shape of the outlet-slot can bring up to six tenth of percent in efficiency.

Topics
Computer simulation
1.
P.
 
Straka
, “
Numerical study of shaft-seal parameters for various geometry configuration and operating regimes
,”
EPJ Web of Conferences
,
180
,
02100
(
2018
).
https://doi.org/10.1051/epjconf/201818002100
Google Scholar
Crossref
Search ADS
 
2.
P.
 
Straka
 and
J.
 
Pelatn
, “
Numerical simulation of flow through a simplified model of the shaft-seal
,”
Proc. Conf. Engineering Mechanics 2018
, pp.
821
–
824
,
Svratka
(
2018
).
Google Scholar
 
3.
P.
 
Straka
, “
Numerical investigation of the hub-seal mass flow rate effect on the axial turbine stage efficiency
,”
Proc. Conf. Experimental Fluid Mechanics 2018
, edited by
P.
 
Dančová
 and
J.
 
Novosád
, pp.
541
–
545
,
Prague
(
2018
).
Google Scholar
Crossref
Search ADS
 
4.
P.
 
Straka
 and
M.
 
Němec
, “
Influence of the radial gap under the stator blade on flow around the hub-end of the rotor blade
,”
Applied Mechanics and Materials
,
821
, pp.
120
–
128
(
2016
).
https://doi.org/10.4028/www.scientific.net/AMM.821.120
Google Scholar
Crossref
Search ADS
 
5.
P.
 
Straka
, “
Modelling of unsteady secondary vortices generated behind the radial gap of the axial turbine blade wheel
,”
Proc. ECCOMAS Congress 2016
,
Crete
(
2016
).
Google Scholar
Crossref
Search ADS
 
6.
P.
 
Straka
, “
Simulation of a 3D unsteady flow in an axial turbine stage
,”
EPJ Web of conferences
,
25
,
01090
(
2012
).
https://doi.org/10.1051/epjconf/20122501090
Google Scholar
Crossref
Search ADS
 
7.
P.
 
Straka
, “Calculation of 3D unsteady turbulent flow in low-power experimental axial turbine stage,”
Report VZLÚ R-5904
,
Prague
(
2013
), (in Czech).
Google Scholar
 
8.
P.
 
Straka
, “Calculation of 3D unsteady inviscid flow in turbine stage ST6,”
Report VZLÚ R-4910
,
Prague
(
2010
), (in Czech).
Google Scholar
 
9.
C. L.
 
Rumsay
 and
T. B.
 
Gatski
, “
Recent turbulence model advances applied to multi-element airfoil computations
,”
Jour. Of Aircraft
,
83
, pp.
904
–
910
(
2001
).
https://doi.org/10.2514/2.2850
Google Scholar
Crossref
Search ADS
 
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2019
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