10. (a) Prove that the centrifugal stress at the root of an untapered blade attached to the drum of anaxial flow turbomachine is given byo. = 7p„N°A‚/1800,where pm = density of blade material, N=rotational speed of drum, in rpm and A, = area ofthe flow annulus.(b) The preliminary design of an axial-flow gas turbine stage with stagnation conditions at stageentry of Po1 = 400 kPa, To1 = 850 K, is to be based upon the following data applicable to themean radius:Flow angle at nozzle exit, a, = 63.8°;Reaction, R=0.5;Flow coefficient, cJUm=0.6;Static pressure at stage exit, p3 = 200 kPa;Estimated total-to-static efficiency, 1s=0.85.Assuming that the axial velocity is unchanged across the stage, determine(i) the specific work done by the gas;(ii) the blade speed;(ii) the static temperature at stage exit.(c) The blade material has a density of 7850 kg/m³ and the maximum allowable stress in therotor blade is 120 MPa. Taking into account only the centrifugal stress, assuming untaperedblades and constant axial velocity at all radii, determine for a mean flow rate of 15 kg/s(1) the rotor speed (rev/min);(ii) the mean diameter;(iii) the hub-tip radius ratio.For the gas assume that Cp=1050 J/(kg K) and R=287 J/(kg K).

Answered: Image /qna-images/answer/11a813c4-70bc-4e46-a125-c34f57fd939e.jpg

Prove that the centrifugal stress at the root of an untapered blade attached to the drum of an axial flow turbomachine is given by ac = xp„N²A‚/1800, where p„= density of blade material, N=rotational speed of drum, in rpm and A, = area of the flow annulus.

Prove that the centrifugal stress at the root of an untapered blade attached to the drum of an axial flow turbomachine is given by ac = xp„N²A‚/1800, where p„= density of blade material, N=rotational speed of drum, in rpm and A, = area of the flow annulus.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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