rical dimensions at the exit from the working wheel, first of all, it is necessary to compute flow parameters in this section.temperature at the exit from the turbine stage is calculated from the equation
;.
pressure at the exit from the turbine stage is calculated by the formula
;,
. component of the jet velocity is assigned at the exit from the working wheel:
;
;;.
velocity is calculated by the formula
;,.
area at the exit from the working wheel is calculated from the equation
;
.
, we assume.dimensions at the working wheel exit:
;
;
;
stage flow duct are drown in scale x: x (see pic xx)
. X.x Turbine stage flow duct
is necessary to determine stage loading coefficient for turbine stage calculation on the middle radius:
;
velocity and reduced velocity at the exit from the nozzle diaphragm is computed supposing axial flow output, ie : br/>
;;
;.
component of the jet velocity and parameter at the entry to the working wheel are calculated by the formulas:
;;
;.
components of the jet velocity at the entry to the working wheel and behind turbine stage, and parameters, and are calculated by the formulas:
;;
;;
;;
;;
;.
gas velocity and its circumferential component can be found from the expressions:
;;
;.
of the stream inlet into the working wheel in the relative direction is computed by formula
;.
velocity and reduced velocity at the exit from the working wheel are calculated by the formulas:
;;
;.
output angle at the exit from the working wheel in the relative direction can be found by the formula
;.
velocity at the exit from the working wheel and its circumferential component are determined by the formulas:
;;
;.
temperature and critical gas velocity in the relative direction are computed from the equations:
;
;
;.
is calculated by the formula
;.
velocities at the entry to the working wheel and behind turbine stage are calculated by the formulas:
;
;
Cinematic reactivity rate is determined from the equation
;.
velocities at the entry to the working wheel and behind it are accepted the same (). Turbine stage work is verified by the equation
;
;
;.
, all calculations are correct.calculate flow parameters on different radiuses, first of all, it is necessary to choose law of profiling across blade height. To do it, calculate reactivity rate an rate index value m = 1:
;
.
, we choose law of circulation constancy across the radius. parameters calculations on different radiuses are summarized in the table xx
Table X.x
Parameter and formulaSectionsleevemiddleperipheral, m0, 6860,7180,75, m/s382400417, 81,681,531,4, m/s222, 9222,9222,9, m/s641, 1612,5586,4, m/s678, 7651,8627 , 3
, 966
, 927
0,892, deg
.3
.3
22.3, m/s259, 1212,5168,6, m/s341, 8308279,5, deg
, 7
, 4
52,9, m/s263, 6263,6263,6, m/s000, m/s263, 6263,6263,6, deg
90
, 4
, 4
0,4, deg
, 6
, 4
32,2, m/s
, 2
494,7, m/s382, 1400418,6, K
1364
, 51
, 46
0,42
, 696
, 716
0,738
, 16
, 234
0,3, J/kg
245314,%
, 04
, 013
0,13 the basis of foregoing calculation we plot speed plans for three sections on blade height (see pic. X).
)
)
). X.x. Axial turbine stage speed plans: - sleeve section; b - middle section; c-peripheral section. br/>
