Question

Steam enters a rotor of an axial turbine with an absolute velocity V₁ = 710 m/s at an angle α1 = 67.5°. The rotor speed is U = 200 m/s. The rotor blades are equiangular so that β2= -β1 and W2=0.91 W1.

(a) Draw the velocity triangles and show the velocity components along the radial and tangential directions.

Find the following.

(b) the relative flow angle β1.

(c) the magnitude of the velocity V₂of the steam that leaves the rotor,

(d) the flow angle α2 that V₂makes with the axial direction.

(e) the specific work of the stage.

U [m/s]	α1	V1 [m/s]	W2 = 0.91 W1
200	67.5°	710

Answer 1

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fxam intet Velocity tsiangle get we wi Sin B Sina lox Sin 67.S WixSin 83.76 2659.86 M/s wI660 m/S Civein Cind Sca and auegatie sign Shows _Oppasite in di'xection B aread taken it in agative we hawe dixection So Prom autlet vetocity_diagram donh WCas-u H hesre NagW Sin Va,- 600x Sin 83.76

and Wa Cos leng th of EH. SOL Apply Ri Py thoagota theoram get we 2 w Sin F) Cos -u 2 +600 XS83.76 2(bcoxSih 83.76 2 -200) 61.U mis fxom AEFH twsin P tund (W Cos B) t600*sings-76) Han o 7 600x (GS 83. 16 -Ro -77R6 Negative Sigin Shods _of angle is 'opposite -to direcstton Magnitude 1277.26 Ans

Specific Woxk in aur Comes Negative Negative sign since is Pfoblem tcuke W Cos Vw Goo X CoS 83.76 134.78 m Vi Cos and 70x CoS 67. 271.-70 Vw, So 200 x 1.70 -134.78 Wa 21385.04 27.38SKJ Ans