3. Turbine blades mounted to a rotating disc in a gas turbine engine are exposed to a gas stream that is at Too=1200°C and maintains a convection coefficient of h =250 W/m² -K over the blade. The blades, which are fabricated from Inconel, k=20 W/m K, have a length of L=50 mm. The blade profile has a uniform cross-sectional area of Ac=6 x 104 m² and a perimeter of P=110 mm. A proposed blade-cooling scheme, which involves routing air through the supporting disc, is able to maintain the base of each blade at a temperature of T₁=300°C. (a) If the maximum allowable blade temperature is 1050°C and the blade tip may be assumed to be adiabatic, is the proposed cooling scheme satisfactory? (b) For the proposed cooling scheme, what is the rate at which heat is transferred from each blade to the coolant? Answer: (a) 1037°C Yes (b) -508W Gas stream To h Air coolant Blade tip - Rotating disk

3. Turbine blades mounted to a rotating disc in a gas turbine engine are exposed to a gas stream that is at Too=1200°C and maintains a convection coefficient of h =250 W/m² -K over the blade. The blades, which are fabricated from Inconel, k=20 W/m K, have a length of L=50 mm. The blade profile has a uniform cross-sectional area of Ac=6 x 104 m² and a perimeter of P=110 mm. A proposed blade-cooling scheme, which involves routing air through the supporting disc, is able to maintain the base of each blade at a temperature of T₁=300°C. (a) If the maximum allowable blade temperature is 1050°C and the blade tip may be assumed to be adiabatic, is the proposed cooling scheme satisfactory? (b) For the proposed cooling scheme, what is the rate at which heat is transferred from each blade to the coolant? Answer: (a) 1037°C Yes (b) -508W Gas stream To h Air coolant Blade tip - Rotating disk

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.33P

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